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Title: Vertebrates from the Barrier Island of Tamaulipas, México

Author: Robert K. Selander
        Richard F. Johnston
        Gerald G. Raun
        B. J. Wilks

Release date: November 13, 2011 [eBook #38004]

Language: English

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        the Online Distributed Proofreading Team at
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UNIVERSITY OF KANSAS PUBLICATIONS
MUSEUM OF NATURAL HISTORY

Volume 12, No. 7, pp. 309-345, pls. 5-8.

June 18, 1962

Vertebrates from the Barrier Island
of Tamaulipas, México

BY
ROBERT K. SELANDER, RICHARD F. JOHNSTON,
B. J. WILKS, AND GERALD G. RAUN

UNIVERSITY OF KANSAS
LAWRENCE
1962




UNIVERSITY OF KANSAS PUBLICATIONS
MUSEUM OF NATURAL HISTORY

Volume 12, No. 7, pp. 309-345, pls. 5-8.

June 18, 1962

Vertebrates from the Barrier Island
of Tamaulipas, México

BY

ROBERT K. SELANDER, RICHARD F. JOHNSTON,
B. J. WILKS, AND GERALD G. RAUN

UNIVERSITY OF KANSAS
LAWRENCE
1962


UNIVERSITY OF KANSAS PUBLICATIONS, MUSEUM OF NATURAL HISTORY

Editors: E. Raymond Hall, Chairman, Henry S. Fitch,
Theodore H. Eaton, Jr.

Volume 12, No. 7, pp. 309-345
Published June 18, 1962

UNIVERSITY OF KANSAS
Lawrence, Kansas

PRINTED BY
JEAN M. NEIBARGER, STATE PRINTER
TOPEKA, KANSAS
1962

29-3002




Vertebrates from the Barrier Island of Tamaulipas, México

BY

ROBERT K. SELANDER, RICHARD F. JOHNSTON, B. J. WILKS, and
GERALD G. RAUN


Lying between the Gulf of Mexico and the Laguna Madre de Tamaulipas is
a narrow barrier island extending from the delta of the Rio Grande
south for 140 miles to within 185 miles of Tampico, Tamaulipas (Plate
5). This island, like most of coastal Tamaulipas, has been all but
neglected by zoological collectors. Consequently, little is known of
the kinds, distribution, and seasonal status of the vertebrates
occurring there. The present paper is a report on land vertebrates
collected and observed on the northern part of the barrier island of
Tamaulipas from July 6 to 10, 1961. Our collection, which has been
deposited in the Museum of Natural History, The University of Kansas,
consists of 63 reptiles, 33 mammals, and 97 birds (58 skins, 19
skeletons, and 20 alcoholics).




Acknowledgments


We are especially indebted to Dr. Charles H. Simpson of Sinton, Texas,
who generously placed at our disposal his truck, a four-wheel drive
"Land Rover," without which travel on the island would have been
difficult. We also acknowledge a loan of field equipment provided by
Dr. Clarence Cottam, Director of the Welder Wildlife Research
Foundation, Sinton, Texas.

Financial support for the present research was provided by grants from
the National Science Foundation to The University of Texas (G 15882)
and to The University of Kansas (G 10043).

Permits to collect vertebrates in México were supplied by Ing. Luis
Macias Arellano, El Director General, Departamento de Conservación de
la Fauna Silves, México, D. F.

We are indebted to Dr. Richard H. Manville for arranging a loan of
specimens of _Geomys personatus tropicalis_ in the United States
National Museum. Dr. Marshall Johnston kindly identified specimens of
plants from the barrier island. Several bones of birds and mammals were
identified by Dr. Pierce Brodkorb and Dr. E. L. Lundelius. Mr. J. Knox
Jones identified some of the mammalian material, and Dr. W. E. Duellman
verified the identifications of the lizards; we thank all of these men
for their willing assistance.




The Ecological Setting


The barrier island of Tamaulipas geologically and ecologically
resembles Padre Island, of the Gulf coast of lower Texas, north of the
mouth and delta of the Rio Grande. South of the delta, the island in
Tamaulipas is a narrow strip of sand less than a mile in average width
and is broken by a series of narrow inlets or "passes" through which
water from the Gulf of Mexico mingles with that of the Laguna Madre de
Tamaulipas. The passes are subject to recurrent opening and closing.
North of the mouth of the Río Soto la Marina, eight passes are
designated by local fishermen, but only three, the Third, Fourth, and
Fifth, were open at the time of our visit.

The Laguna Madre de Tamaulipas is described by Hildebrand (1958) in
connection with a preliminary study of the fishes and invertebrates
there. The average depth is probably less than 70 cm. and the waters
are hypersaline. In the time of the recent drought in Texas and
northeastern México, salinity varied from 108 to 117 parts per thousand
in the northern part of the laguna near Arroyo del Tigre (measurements
taken in March, 1955) to from 39 to 48 parts per thousand in the
southern part near Punta Piedras (measurements taken in October and
November, 1953, and in March, 1954). Discussions of the geologic
history, ecology, and zoogeography of the lagoons of the Gulf coast of
the United States are given by Hedgpeth (1947; 1953).

Localities in coastal Tamaulipas mentioned in the text of this paper
are shown on Plate 5.

The principal animal habitats are found in three vegetational
associations (plates 6 and 7). On flats and low dunes lying between,
and partly sheltered by, larger active dunes, small clumps of _Croton
punctatus_ and a sedge (_Fimbristylis castanea_) are the only
conspicuous plants. Near the western edge of the dunes, _Ipomoea
pescaprae_ var. _emarginata_ is mixed with _Croton_, and there are
scattered clumps of shrubby wolf-berry (_Lycium carolinianum_ var.
_quadrifidum_), and mesquite (_Prosopis juliflora_).

The dunes are relatively stabilized on the western side of the island,
and there we found moderately dense stands of mesquite trees reaching
heights of from eight to 10 feet. Prickly-pear cactus (_Opuntia
lindheimeri_) was common in those stands of mesquite, and we saw an
occasional yucca tree. A fairly dense ground cover was formed by
blanket-flower (_Gaillardia pulchella_), marsh-elder (_Iva_ sp.),
_Flaveria oppositifolia_, _Enstoma exaltatum_, and _Croton capitatus_
var. _albinoides_.

A more open, xeric expression of the mesquite-cactus vegetation occurs
on exposed, low clay dunes (see description by Price, 1933) located on
alkaline flats bordering the laguna. At the time of our visit, most of
the mesquites in these stands were dead or dying, the cactus was
abundant, and the ground cover, which was sparse, included drop-seed
(_Sporobolus virginicus_), ragweed (_Ambrosia psilostachya_), and
_Commicarpus scandens_.

On alkaline flats flooded by hypersaline waters of the laguna following
heavy rains, _Batis maritima_ is found in the lower areas, but on the
slightly elevated areas there is low and almost continuous cover of
_Monanthochloë littoralis_, in which can be found _Batis_, _Borrichia
fructescens_, _Salicornia_ sp., _Iva_ sp., and sea-lavender (_Limonium
carolinianum_).

Near Third Pass, sea oats (_Uniola paniculata_), evening primrose
(_Oenothera_ sp.), and cordgrass (_Spartina_ sp.) are present on the
dunes, and on alkaline flats we collected _Conocarpus erectus_,
_Leucaena_ sp., and _Cassia fasciculata_ var. _ferrisiae_.




Itinerary


We reached Washington Beach from Matamoros on July 6, and drove to a
point approximately 33 miles south on the beach, where we made Camp 1
on the east side of large dunes 400 yards from the surf. From this camp
we worked the beach and dunes and also visited alkaline flats adjacent
to the Laguna Madre. On the afternoon of July 8, we drove south along
the beach and established Camp 2 on the south side of the Third Pass,
approximately 73 miles south of Washington Beach. We had intended to go
farther south but were unable to cross the Fourth Pass, an inlet three
miles south of the Third Pass. We left the barrier island on the
afternoon of July 10, after driving north from Camp 2 to the mouth of
the Rio Grande, 11 miles north of Washington Beach.

Mexican fishermen camped at the Fourth Pass told us that, had we been
able to cross the Fourth Pass, it would have been possible to drive
south on the beach all the way to La Pesca, a fishing village near the
mouth of the Río Soto la Marina, approximately 150 miles south of
Washington Beach.




Summary of Previous Work in the Area


The ornithologist H. E. Dresser (1865-1866) worked in southern Texas
and at Matamoros, Tamaulipas, in 1863, and on one occasion reached the
mouth of the Rio Grande ("Boca Grande"). He did not visit the barrier
island or the Laguna Madre de Tamaulipas.

In their extensive travels through México, E. W. Nelson and E. A.
Goldman made collections at three localities in the coastal region of
Tamaulipas but did not reach the barrier island (Goldman, 1951).
Goldman collected at Altamira, near Tampico, from April 2 to 24, 1898,
and from May 15 to 20 of the same year both he and Nelson made
headquarters at Altamira. Nelson and Goldman also collected in the
vicinity of Soto la Marina, 25 miles from the coast, from March 1 to
10, 1902, and, from February 13 to 15, they visited Bagdad, described
by Goldman (1951:260) as "a village at very low elevation on the Río
Grande about 6 miles above the mouth of the river."

In March, 1950, C. von Wedel and E. R. Hall collected four species of
mammals and one bird on the barrier island at Boca Jésus María (Eighth
Pass). A report of this work published by Hall (1951) contains
descriptions of three new subspecies of mammals from the island.

A few records of birds from the southern end of the barrier island and
from other parts of coastal Tamaulipas were reported by Robins, Martin,
and Heed (1951). In 1953, R. R. Graber and J. W. Graber made
ornithological studies in the vicinity of Tampico and also reached the
western edge of the Laguna Madre de Tamaulipas. Several papers on this
work have appeared (Graber and Graber, 1954_a_, 1954_b_; Graber, 1955),
but a comprehensive account of their observations and specimens was not
published. Finally, J. R. Alcorn collected some sandpipers 20 miles
southeast of Matamoros, on August 21, 1954, obtaining the first record
of the Semipalmated Sandpiper (_Ereunetes pusillus_) in Tamaulipas
(Thompson, 1958).




Accounts of Species


Catalogue numbers in the following accounts are those of the Museum of
Natural History, The University of Kansas.


_Reptiles_

=_Gopherus berlandieri_= Agassiz: Texas Tortoise.--A pelvic girdle and
complete shell with a few attached scutes (63494) were found in
stabilized dunes at Camp 1 on July 7, and tracks were seen in the same
area. Fragments of two other shells (63493, 63495) were found on sand
flats between active dunes at Camp 1.

=_Holbrookia propinqua propinqua_= Baird and Girard: Keeled Earless
Lizard.--This lizard was abundant on dunes and in pebble-strewn
blow-out areas between dunes at Camp 2, but it occurred in smaller
numbers in the less stabilized dunes of sparser vegetation at Camp 1.
Breeding was in progress at both localities, as evidenced by the
presence of eggs in the oviducts of several females, by the heightened
coloration of both sexes, and by mating behavior.

The mating behavior of this species has not been described in the
literature, and the following observations, made by Raun at Camp 2 on
July 8, may be of interest. A male was seen to circle a female as the
latter remained motionless with tail curved upward and to the side,
exposing a patch of bright pink-orange color on the ventral surface of
the tail. At times the male approached the female from the rear and
slightly to the side, biting the dorsal part of her neck and
simultaneously attempting to effect intromission. The female several
times reacted to this approach by running forward a few steps, thereby
freeing her neck from the grasp of the male. When the male did not
attempt to approach again, the female appeared to invite copulation by
moving in front of him with tail elevated and the colored ventral
surface prominently displayed. At the time of copulation, the male
mounted from the rear on the right side of the female, grasped her
neck, and circled his tail beneath her tail; at the same time the
hindquarters of the female were arched upward.

To confirm the presumed sexes of the two individuals under observation,
both were collected while in copulation. Examination of the
still-coupled specimens showed that both hemipenes of the male were
everted and the left one had been inserted.

Apparently the pink-orange subcaudal patch of females is present only
in the mating season. It was not present on specimens of this species
taken by Raun and Wilks on Padre Island, Texas, in autumn, and it is
not mentioned in taxonomic descriptions by Axtell (1954) and Smith
(1946).

Measurements of adult specimens in our series indicate that females are
of smaller average size than males, and, as previously noted by Smith
(1946:132), females of this species have disproportionately shorter
tails than do males (Table 1).

_Holbrookia propinqua_ was previously collected on the barrier island
by Axtell (1954:31; see also Axtell and Wasserman, 1953:2), who took
specimens at Boca Jésus María, at a locality six to seven miles south
of Boca Jésus María, and at a point 20 miles east-southeast of
Matamoros. Axtell (_loc. cit._) also lists specimens in the Museum of
Zoology, University of Michigan, from Tepehuaje and from one mile north
of Miramar Beach (Tampico).

Specimens (56): 3 [M] [M] adult, 1 [M] subadult, 63433-436, Camp 1,
July 7. 33 [M] [M] adult, 63437-440, 63443-445, 63447, 63448,
63450-456, 63458, 63460, 63462, 63463, 63465-468, 63470-478; 13 [F]
[F] adult, 63441, 63446, 63449, 63457, 63459, 63469, 63479-485; 6 juv.,
63442, 63461, 63464, 63486-488; Camp 2, July 9-July 10.

TABLE 1.--MEASUREMENTS IN MILLIMETERS OF ADULT SPECIMENS OF _Holbrookia
propinqua_ FROM THE BARRIER ISLAND OF TAMAULIPAS

=======+===========+=============+==========+===============
       |  Number   |             |          |    Ratio:
  SEX  |    of     | Snout-vent  |   Tail   |  snout-vent
       | specimens |   length    |  length  |    to tail
-------+-----------+-------------+----------+---------------
Male   |    33     | 56.0±0.5[A] | 77.0±0.7 |  0.731±0.001
       |           |  (49-62)    |  (69-85) | (0.682-0.817)
-------+-----------+-------------+----------+---------------
Female |    14     | 50.9±0.5    | 62.2±0.9 |  0.825±0.001
       |           |  (47-53)    |  (57-68) | (0.735-0.877)
-------+-----------+-------------+----------+---------------

[Footnote A: Mean ± standard error; range indicated in parentheses.]

=_Cnemidophorus gularis_= Baird and Girard: Whip-tailed Lizard.--At
both camps we found this species in the same general habitat in which
_Holbrookia_ occurred, but in numbers decidedly fewer than the latter.

Specimens (4): 2 [F] [F] adult, 63489, 63490, Camp 1, July 7. 1 [M]
adult, 63491, 1 [F] adult, 63492, Camp 2, July 9.

We failed to take specimens of snakes on the barrier island, but tracks
of snakes were noted on two occasions in dunes near Camp 1; one trail
led into a burrow of a kangaroo rat.


_Birds_

Unless otherwise indicated, specimens taken were not molting. For birds
undergoing postnuptial or postjuvenal molt, the degree of advancement
of the molt is indicated by recording the number of primaries of the
old plumage that have not been dropped. For example, the designation "4
P old" signifies that all primaries except the distal four have been
molted.

Table 2 presents results of a strip census of birds along the strand,
made by three of us from the moving truck on the morning of July 10.
Birds characteristically found on sand near the surf were thus
conveniently counted in accurate fashion. Birds not ordinarily found on
the strand could not be treated this way; most were considerably less
abundant than the eight most numerous species listed in Table 2.
Over-all, the numbers of individuals listed are a good index of
abundance of the Great Blue Heron and of the common charadriiform birds
on the beach in early July. The Black Tern is an exception, however,
and this is discussed in the account of that species on page 327.

TABLE 2.--BIRDS[A] RECORDED ALONG 17 MILES OF BEACH[B] ON THE BARRIER
ISLAND OF TAMAULIPAS

=====================+=============+================
       Species       |   Number    | Birds per mile
---------------------+-------------+----------------
Great Blue Heron     |           9 |         0.5
Oyster-catcher       |           1 |         0.1
Black-bellied Plover |          20 |         1.2
Wilson Plover        |          53 |         3.1
Willet               |          43 |         2.5
Sanderling           |          55 |         3.2
Laughing Gull        |         136 |         8.0
Black Tern           |          19 |         1.1
Caspian Tern         |          82 |         4.8
Least Tern           |         221 |        13.0
Royal Tern           |         301 |        17.7
Cabot Tern           |         122 |         7.2
                     +-------------+----------------
                     | Total: 1062 | Total: 62.4
---------------------+-------------+----------------

[Footnote A: Common Tern, Forster Tern, and Long-billed Curlew also
seen but not counted.]

[Footnote B: Between 56 and 73 miles south of Washington Beach, 11:00
to 11:45 a. m., July 10, 1961.]

=_Pelecanus erythrorhynchus_= Gmelin: American White Pelican.--A flock
of approximately 300 individuals was seen resting at the edge of the
Laguna Madre near Camp 2 on July 9. When disturbed by gunshots, the
birds circled high over the laguna and flew to the west. Among bones
found on sand flats at Camp 1 are a left tarsometatarsus and a pedal
phalanx of an American White Pelican.

Supposedly the only breeding colony of this species on the northern
Gulf coast is one in the Laguna Madre near Corpus Christi (Peterson,
1960:8), but the possibility of one or more such colonies existing in
northeastern Tamaulipas has been suggested by Amadon and Eckelberry
(1955:68) on the basis of their observations of individuals seen
soaring near the coast 15 to 20 miles south of Brownsville on April 15
and June 5, 1952. According to Hildebrand (1958:153, and personal
communication, August 14, 1961), small colonies of white pelicans do
breed in some years on two small islands, in the Laguna Madre of
Tamaulipas, located at 25° 26´ North and 93° 30´ West.

In Veracruz the species is recorded as a winter visitant and transient
(Loetscher, 1952:22; Amadon and Eckelberry, 1955:68). Coffey (1960:289)
reports the following observations for Veracruz and Tamaulipas: a flock
of 52 between Tlacotalpan and Alvarado, May 29, 1951; 80 near
Cacaliloa, April 20, 1958; 180 birds north of Alvarado, April 24, 1958;
four at Altamira, May 28, 1955; flocks of three, 13, and 37 "south" of
Matamoros, May 20, 1951; 72 at Lomas del Real, November 20, 1956.

=_Pelecanus occidentalis_= Gmelin: Brown Pelican.--Three individuals
flew north over the surf near Camp 1 on July 7, and a lone bird was
seen diving into the Gulf a short distance beyond the surf near Camp 2
on July 9. Birds seen by us probably were of the population named _P.
o. carolinensis_, which is resident along the Gulf coast (Mexican
Check-list, 1950:21).

=_Phalacrocorax_= sp.: Cormorant.--From 80 to 100 adult and juvenal
cormorants were on the laguna at Camp 2 on July 8 and 9. Probably they
were Common Cormorants (_P. olivaceus_), but, because specimens were
not taken, we cannot eliminate the possibility that some (or all) were
Double-crested Cormorants (_P. auritus_). The former breeds in coastal
lowlands of eastern México, whereas the latter is known in eastern
México only as a winter visitant and has not been recorded in
Tamaulipas (Mexican Check-list, 1950:24).

=_Fregata magnificens_= Mathews: Magnificent Man-o'-war Bird.--An
observation of a lone bird circling high over the laguna at Camp 2 on
July 9 seemingly constitutes the third record of this species in
Tamaulipas. Previous records were reported by Robins, Martin, and Heed
(1951:336), who found "large numbers" in the Barra Trinidad region (8
miles north of Morón) on April 27 to 29, 1949, and mentioned an
immature male taken at Tampico on April 23, 1923; this specimen has
been identified by P. Brodkorb as _F. m. rothschildi_.

=_Ardea herodias_= Linnaeus: Great Blue Heron.--Our records of this
heron are limited to the following observations: four individuals on
the beach and seven in the laguna at Camp 1, July 7; one on the beach
52 miles south of Washington Beach, July 8; one 74 miles south of
Washington Beach, July 8; two at Third Pass, July 8; 41 standing on
mud-flats at the edge of the laguna near Camp 2, July 9; nine on the
beach 56 to 73 miles south of Washington Beach, July 10; one on the
beach 42 miles south of Washington Beach, July 10.

The status of the Great Blue Heron in coastal Tamaulipas remains to be
determined. The subspecies _A. h. wardi_ (considered a synonym of _A.
h. occidentalis_ by Hellmayr and Conover, 1948) is resident and breeds
on the Gulf coast of Texas and is to be expected as a resident in
Tamaulipas (Mexican Check-list, 1950:27). The species may breed south
to Veracruz, where Loetscher (1955:22) reports it is "regular at nearly
all seasons, chiefly on the coastal plain"; he records an observation
near Tamós on July 1. The subspecies _A. h. herodias_ and _A. h.
treganzai_ winter through much of México and have been recorded in
Tamaulipas (Mexican Check-list, 1950:27).

=_Florida caerulea_= (Linnaeus): Little Blue Heron.--We saw a white
(immature) individual feeding with Reddish Egrets along an inlet at
Camp 2 on July 8.

=_Dichromanassa rufescens rufescens_= (Gmelin): Reddish Egret.--This
egret was recorded only about the inlet at Camp 2, where 15 individuals
were feeding, either singly or in small groups, on July 8 and 9. We
noted frequent use of the "Open Wing" method of foraging, as described
by Meyerriecks (1960:108).

Specimen: [F] juv., 38899, ovary inactive, 587 gm., Camp 2, July 8.
This specimen is referable to the nominate subspecies, which is
resident along the Gulf coast. Our record seems to be the first for the
species in Tamaulipas.

=_Leucophoyx thula_= (Molina): Snowy Egret.--Ten individuals of this
species were feeding in association with Reddish Egrets in the inlet at
Camp 2 on July 9.

=_Hydranassa tricolor_= (P. L. S. Müller): Tricolored Heron.--An
observation of one individual flying along the margin of the laguna
near Camp 2 is our only record of this species.

=_Nycticorax nycticorax_= (Linnaeus): Black-crowned Night Heron.--This
heron was found only at the edge of the laguna near Camp 2; ten
individuals were noted on July 8, and 20 were seen perched in a clump
of mesquite trees on July 9. Perhaps half the birds seen were in
juvenal plumage. A juvenile was shot and examined on July 9 but was not
preserved as a specimen.

There appears to be no definite evidence of breeding by this species in
Tamaulipas (Mexican Check-list, 1950:32), but such may be expected
because the species breeds locally in Texas (Peterson, 1960:19) and in
Veracruz.

=_Ajaia ajaja_= (Linnaeus): Roseate Spoonbill.--On July 9 at Camp 2,
38 spoonbills flew up from the edge of the laguna where they had been
resting near a large flock of white pelicans.

=_Cathartes aura_= (Linnaeus): Turkey Vulture.--One Turkey Vulture was
seen flying east at a point 2 miles west of Washington Beach on July
10. It is noteworthy that we saw no Yellow-headed Vultures (_C.
burrovianus_), a species recently recorded in the region of Tampico
north to Lomas del Real (Graber and Graber, 1954_a_).

=_Colinus virginianus texanus_= (Lawrence): Bob-white.--This species
was seen only in or near clumps of mesquite near Camp 1, where three
covies (7, 13, and 18 individuals) were flushed on July 7. Specimen:
[M] juv., 38900, testis 3 mm., 100 gm., 6 P old, Camp 1, July 7.

=_Porzana carolina_= (Linnaeus): Sora Rail.--On sand flats at Camp 1 we
found a left humerus and several other post-cranial skeletal elements
that have been identified by Dr. Pierce Brodkorb as belonging to this
species. All the bones are of Recent age. We have no other record of
the Sora Rail on the barrier island, but in all probability it occurs
as a migrant and winter visitant along margins of the laguna.

=_Haematopus ostralegus_= Linnaeus: Oyster-catcher.--One individual was
seen at Camp 2 on July 8, three were noted at the same locality on July
9, and one was present on the beach 72 miles south of Washington Beach
on July 10. The only previous records of this species in Tamaulipas are
a specimen ([M], 29348) taken by E. R. Hall 10 miles west and 88 miles
south of Matamoros on March 20, 1950 (herewith reported for the first
time), and three seen on the beach near Tepehuaje on May 9, 1949
(Robins, Martin, and Heed, 1951).

=_Squatarola squatarola_= (Linnaeus): Black-bellied Plover.--Plovers of
this species were uncommon but regular on the beach; frequently two
individuals were seen together, sometimes in association with one or
more Willets. Specimens (4): [M], 38915, testis 4 mm., 231 gm.; [M],
38914, testis 4 mm., 221 gm.; [M], 38916, testis 3 mm., 209 gm., Camp
1, July 7. Male, 38917, testis 4 mm., 186 gm., Camp 2, July 9. The
specimens were molting (3-4 P old) into winter plumage and showed
little or no subcutaneous fat.

Our specimens and records probably pertain to nonbreeding individuals
summering on the coast, as the species is known to do in Texas (Hagar
and Packard, 1952:9) and elsewhere in its range (Eisenmann, 1951:182;
Haverschmidt, 1955:336; A.O.U. Check-list, 1957:174). In any event,
our dates (July 6 to 10) are unusually early for autumnal migrants;
they do not reach Texas until August (Peterson, 1960:94), and Loetscher
(1955:26) gives August 7 as the earliest date for southbound migrants
in Veracruz.

=_Charadrius hiaticula semipalmatus_= Bonaparte: Ringed Plover.--We
have a single record, an adult male (38913, testis 2 × 1 mm., heavy
fat, 47.0 gm., 4 P old) taken on a sandbar at Camp 2 on July 9. The
bird was feeding in company with a flock of Sanderlings.

There is no previous record of the Ringed Plover in Tamaulipas. In
Texas, Hagar and Packard (1952:8) indicate that the first autumnal
migrants reach the central Gulf coast in the last week of July. In
coastal México, the species has previously been recorded from August 23
to May 12 (Mexican Check-list, 1950:91). Therefore, the present record
must represent an exceptionally early southbound migrant, or, more
probably, a nonbreeding, summering individual. According to the A.O.U.
Check-list (1957:166), nonbreeding birds are found in summer in coastal
areas south to California, Panamá, and Florida. Many individuals spend
the northern summer along the coast of Surinam (Haverschmidt,
1955:336).

=_Charadrius wilsonia wilsonia_= Ord: Wilson Plover.--This small plover
breeds commonly on the beach and on alkaline flats adjacent to the
laguna. Previous evidence of breeding in Tamaulipas consisted only of a
report of a male with brood patches and an enlarged testis taken near
Tamós on May 30, 1947 (Loetscher, 1955:26).

We saw many pairs of adults and a large number of well-grown juveniles,
and, at a point 4 miles south of Washington Beach, we collected a brood
of three small juveniles that had only recently hatched. The breeding
season apparently was drawing to a close, for several adults in our
collection were in postnuptial molt and showed marked gonadal
regression. From July 6 to 9, a few small groups of birds were noted,
but large groups were not seen until July 10, when several flocks of up
to 60 individuals were found along the coast 3 to 7 miles south of
Washington Beach.

Specimens (12): [M], 38904, testis 4.5 × 2 mm., 58 gm., 3 P old, brood
patches refeathering; [M], 38905, testis 5 × 2 mm., 59 gm., 4 P old,
brood patches refeathering; [M] juv., 38903, 6.2 gm.; 2 sex?, 38901,
38902, 5.7 and 6.2 gm., 4 miles south of Washington Beach, July 6.
Male, 38907, testis 5 × 2 mm., 56 gm., 7 P old, brood patches
refeathering; [F], 38906, ova to 1 mm., 61 gm., 3 P old, brood patches
refeathering; [F] juv., 38908, ovary inactive, 54 gm., in body molt;
Camp 1, July 6. Male, 38910, testis 6 × 3 mm., 60 gm., 4 P old; [F],
38909, ova to 1 mm., 57 gm., 4 P old, brood patches refeathering; Camp
1, July 8. Male, 38911, testis 2 × 1 mm., 55 gm.; juv., 38912, no
weight or sex recorded; Camp 2, July 9.

=_Numenius americanus parvus_= Bishop: Long-billed Curlew.--Lone
individuals and groups of two to five were noted occasionally along the
beach each day. In total, some 30 to 50 birds were counted, but some
individuals may have been recorded more than once on different days.
Specimens (2): [M], 38918, testis 4 mm., some fat, 459 gm., Camp 2,
July 9; [F], 38933, ova to 1 mm., no weight recorded, Camp 2, July 8.

Our assumption that some or all individuals seen by us were
nonbreeding, summering birds is supported by the fact that our
specimens are referable to the small, northwestern subspecies, _N. a.
parvus_, rather than to _N. a. americanus_; the latter breeds south in
the eastern United States to south-central Texas (A.O.U. Check-list,
1957:181). Loetscher (1955:27) saw a flock of 39 curlews near Tamós on
June 30, and he notes that nonbreeding birds are fairly common at all
seasons in Veracruz. Similarly, the species is present throughout the
year on the central Gulf coast of Texas (Hagar and Packard, 1952:8).
Authors of the Mexican Check-list (1950:94) do not mention the
possibility that birds of this species recorded in México in July are
summering rather than migrating. Twelve supposed migrants seen along
Laguna Chila (Cacalilao), Veracruz, by Coffey (1960:291) on May 31,
1957, may have been summering birds.

=_Limosa fedoa_= (Linnaeus): Marbled Godwit.--Three were seen in
shallow waters of the laguna at Camp 2 on July 9. Specimen: [M], 38919,
testis 6 × 2 mm., fat, 305 gm., 6 P old, Camp 2, July 9. Probably our
records were of nonbreeding birds, which are known to occur in summer
elsewhere in México (Mexican Check-list, 1950:94), sparingly in Texas
(Hagar and Packard, 1952:8), and in South Carolina (A.O.U. Check-list,
1957:205). Apparently the only record for this species in Veracruz is
one seen on May 11, 1954, east of Cacalilao (Coffey, 1960:292).

=_Tringa melanoleuca_= (Gmelin): Greater Yellowlegs.--Three birds were
seen on alkaline flats at Camp 1 on July 7, and two were noted at Camp
2 on July 9. There is one previous report of this species in
Tamaulipas, and, since it has been recorded as a migrant and winter
resident in México between July 26 and April 26 (Mexican Check-list,
1950:95), our records seem to pertain to unusually early autumnal
migrants or, possibly, to nonbreeding, summering birds. Other
mid-summer records are available from Tamós on June 30 and July 1, and
the species is "to be expected every month of the year" in Veracruz
(Loetscher, 1955:27). Sight records for Veracruz in May (Coffey,
1960:291) may well pertain to summering birds. There are
northern-summer records for this species from Texas (Hagar and Packard,
1952:8), Surinam (Haverschmidt, 1955:367), and other areas within the
winter range of this yellowlegs (A.O.U. Check-list, 1957:190).

=_Catoptrophorus semipalmatus semipalmatus_= Gmelin: Willet.--The
Willet was common on the island. We found evidence of breeding and also
saw large flocks of birds that were either nonbreeders summering in the
area or early, postbreeding migrants from more northerly places. All
along the beach and at the edge of the laguna at both camps we found
Willets in twos or threes, often accompanied by one or two
Black-bellied Plovers. On July 10 a small juvenile was captured; two
adults in breeding plumage evidenced obvious concern at this action. On
July 6 a flock of 30 birds flew east over Camp 1, and a flock of 90 was
seen flying south over Camp 1 on July 7.

Specimens (7): [M], 38922, testis 6 × 1 mm., 264 gm., breeding plumage;
[F], 38923, ova to 2 mm., 269 gm., breeding plumage; [F], 38924, ova to
1 mm., 280 gm., 3 P old; [F], 38925, ova to 1 mm., 319 gm.; [M], 38921,
testis 7 × 2 mm., 211 gm., breeding plumage; Camp 1, July 7. Male,
38927, fat light, 231 gm., 4 P old, Camp 2, July 9. Juvenile, sex not
recorded, 38920, 43.0 gm., 1 mile south of Washington Beach, July 10.
Two of our specimens, both males, are in worn breeding plumage and
evidence no molt; another specimen, a female, is also in breeding
plumage but is molting on the breast. The remaining two adult skins in
our series are three-quarters through the molt and are for the most
part in fresh winter feather.

Dresser (1866:37) took an unspecified number of specimens of the Willet
at the "Boca Grande" in July and August, but actual breeding in
Tamaulipas was first established by C. R. Robins, who found a
"scattered colony of breeding Willets" and took a female with an egg in
the oviduct on May 9, 1949, near Tepehuaje (Sutton, 1950:135). Sutton
(_op. cit._) has discussed the characters of this specimen and of birds
from Cameron County, Texas. The specimen from Tepehuaje reportedly is
closer to _C. s. inornatus_ than to _C. s. semipalmatus_ both in size
and color, and birds from Cameron County are intermediate between the
two subspecies in size but like _C. s. inornatus_ in color.

TABLE 3.--MEASUREMENTS IN MILLIMETERS OF SPECIMENS OF CATOPTROPHORUS
SEMIPALMATUS FROM THE BARRIER ISLAND OF TAMAULIPAS

=============+======+======+========+========+========
   SEX AND   |      |      |        |        | Weight
  CATALOGUE  | Wing | Tail |  Full  | Tarsus |   in
   NUMBER    |      |      | culmen |        |  grams
-------------+------+------+--------+--------+--------
[M] 38921[A] |  197 | 80.6 |  61.0  |  59.0  |   211
[M] 38922[A] |  198 | 74.4 |  61.9  |  57.9  |   264
[M] 38927    |  194 | 75.5 |  60.4  |  56.4  |   231
[F] 38923[A] |  201 | 71.0 |  59.0  |  55.4  |   269
[F] 38924    |  199 | 71.0 |  61.3  |  59.0  |   280
-----------+------+------+--------+--------+--------

[Footnote A: Specimens in worn breeding plumage.]

Measurements of our five adults from the barrier island are presented
in Table 3 for comparison with those of _C. s. semipalmatus_ and _C. s.
inornatus_ given by Ridgway (1919:316-319). Like the specimens from
Cameron County examined by Sutton (_op. cit._), our birds are
intermediate in size between average-sized individuals of the two named
subspecies. In color and pattern, we find that our specimens in
breeding plumage fall within the range of variation of _C. s.
semipalmatus_ as exemplified by five specimens in nearly identical
states of wear and fading in the Museum of Natural History.

On the basis of the evidence presently available, we are reluctant to
follow Sutton (1950:136) in assigning breeding birds from the Gulf
coastal region to _C. s. inornatus_, a name otherwise applied to a
population of birds breeding inland, in northwestern North America
south to central Utah and Colorado and east to South Dakota (and
formerly to western and southeastern Minnesota and Iowa; see A.O.U.
Check-list, 1957:190). The intermediate characters of birds breeding in
coastal Texas and Tamaulipas probably represent not the results of
actual genetic intermixing of the two named populations but, rather, an
adaptive response of the eastern coastal stock (_C. s. semipalmatus_)
to environmental modalities distinct from those operating elsewhere
within the range of the eastern coastal population or on the inland
population. Accordingly, we tentatively use the name _C. s.
semipalmatus_ for our Tamaulipan specimens, realizing that the patterns
of geographic variation in the species do not lend themselves well to
taxonomic treatment by the trinomial nomenclatural system. The need
for a comprehensive analysis of geographic variation in this species,
based, if possible, on proper segregation of age classes along the
lines followed by Pitelka (1950) for _Limnodromus_, is obviously
indicated.

PLATE 5

[Illustration: Map of coastal Tamaulipas, showing the barrier island
and localities mentioned in text. Stippled areas are extensively
marshy.]

PLATE 6

[Illustration: FIG. 1.--_Croton_ and _Fimbristylis_ on stabilized
dunes; the Laguna Madre and surrounding alkaline flats and clay dunes
are visible in the background. Habitat of Road-runner, Ord kangaroo
rat, and keeled lizard.]

[Illustration: FIG. 2.--Active dune near Camp 1. Other active dunes can
be seen in the background, in the right foreground is a clump of
_Croton_, and in the left foreground is a small clump of
_Fimbristylis_. Habitat of Road-runner, Ord kangaroo rat, and keeled
lizard.]

=_Arenaria interpres morinella_= (Linnaeus): Turnstone.--Approximately
40 individuals were noted along the beach from July 6 to 10, mostly in
small groups; the largest flock included 15 individuals. Specimens (5):
[M], 38931, testis 4 × 1 mm., moderately fat, 107 gm., 4 P old; [M],
38932, testis 3 × 1 mm., moderately fat, 103 gm., molting; 75 miles
south of Washington Beach, July 8. Male, 38928, testis 2 mm., 111 gm.,
3 P old; [M], 38929, testis 3 mm., moderately fat, 106 gm., 6 P old;
[M], 38930, testis 2.5 mm., moderately fat, 108 gm., 6 P old; Camp 2,
July 9.

The only previous record of the Turnstone in Tamaulipas is an
observation of an unspecified number at Tepehuaje on May 9, 1949
(Robins, Martin, and Heed, 1951). The dates of our records suggest that
nonbreeding birds summer along the coast of Tamaulipas. The species is
present in small numbers in summer along the central Gulf coast of
Texas (Hagar and Packard, 1952:8). Loetscher (1955:26-27) does not
report records for Veracruz in summer, but records of the species in
Yucatán on May 31, 1952 (Paynter, 1955:101), and on June 16, 1900
(Mexican Check-list, 1950:79), probably represent summering
nonbreeders. Probably also in the same class are supposed "migrants"
seen at Coatzacoalcos on May 17, 1954, and June 4, 1955 (Coffey,
1960:290).

Inasmuch as Haverschmidt (1955:368) reports that nonbreeding birds
summering in Surinam only occasionally assume breeding plumage, it is
noteworthy that our specimens were molting from nuptial (summer) to
winter plumage. None of the nonbreeding northern shorebirds observed by
Eisenmann (1951:183) in Panamá in summer were in nuptial plumage.

=_Crocethia alba_= (Pallas): Sanderling.--This sandpiper was noted each
day along the beach, occasionally singly but more frequently in groups
ranging from 10 to 50 individuals. Specimens (7): [M], 38936, testis 2
mm., light fat, 49 gm., 5 P old, Camp 1, July 7. Female, 38937, ova to
1 mm., fat, 58 gm., 4 P old; [M], 38939, fat, no weight recorded, 6 P
old, breeding plumage; 3 [M] [M], 38940-38942, fat, no weight recorded,
4-5 P old; Camp 2, July 9.

With one exception as noted, our specimens are in worn, nonbreeding
plumage and are replacing their old feathers with new ones
fundamentally the same in color and pattern; the exceptional specimen
is molting from worn breeding plumage into nonbreeding plumage. Only
one other individual in breeding feather was seen on the island.

According to the Mexican Check-list (1950:99), the Sanderling has been
recorded in México from August to May 19. In Texas, Peterson (1960:107)
reports that it is a migrant, April to June and July to November, and
that it winters along the coast. We suspect that many of the birds
present in Texas in June and July, together with those recorded by us
in Tamaulipas in July, are nonbreeding, summering individuals.
Haverschmidt (1955:368) reports northern-summer records from Surinam,
and, according to the A.O.U. Check-list (1957:208), nonbreeding birds
occur in summer extensively through winter range of the species,
including the Gulf coast of the United States.

=_Micropalama himantopus_= (Bonaparte): Stilt Sandpiper.--Two birds in
worn winter plumage were taken as they foraged together at the edge of
the laguna near Camp 2 on July 9. Specimens (2): [M], 38934, testis 2.5
mm., heavy fat, 116 gm., 4 P old; [M], 38935, testis 3 mm., fat, 111
gm., 4 P old.

Our specimens probably were nonbreeding birds summering between the
breeding range in arctic America and the winter range in northern South
America. The A.O.U. Check-list (1957:202) does not mention nonbreeding,
summering records of this species. The 251 birds seen by Coffey
(1960:292) at Cacalilao, Veracruz, on May 11, 1954, were probably
migrants.

=_Recurvirostra americana_= Gmelin: American Avocet.--This species was
seen only in three large flocks flying south along the beach, as
follows: 56 birds 72 miles south of Washington Beach, July 8; 38 birds
73 miles south of Washington Beach, July 8; 29 birds 72 miles south of
Washington Beach, July 10. All birds were in winter plumage.

All these birds were possibly autumnal migrants, but the dates are
early; the species has not previously been recorded on migration in
México before August (Mexican Check-list, 1950:101). The species is
known to breed in San Luis Potosí (Mexican Check-list, _loc. cit._) and
along the lower coast of Texas ("rarely to Brownsville"; A.O.U.
Check-list, 1957:209); avocets thus may also breed in coastal
Tamaulipas.

=_Larus argentatus_= Pontoppidan: Herring Gull.--A first-year bird was
observed near Camp 2 on July 8, and two subadult individuals were seen
on the beach between the Third and Fourth passes on July 8.

=_Larus atricilla_= Linnaeus: Laughing Gull.--This gull was common all
along the beach. Many individuals were in full breeding feather and
many subadult birds were also present. Specimens (6): [M] subadult,
38944, testis 5 × 1 mm., 325 gm., molting; [F], 38945, ovary small, 309
gm., in molt, brood patches refeathering; sex?, 38943, 315 gm., in
molt; sex? subadult, 38946, 327 gm., in molt; Camp 1, July 7. Female
subadult (second-year), 38947, 305 gm., in molt, Camp 2, July 8.
Female, 38926, ova to 2.5 mm., 313 gm., 8 P old, Camp 2, July 10.

The Mexican Check-list (1950:105) refers to the Laughing Gull as a
common winter resident on both coasts of México from August 7 to May
17, but Loetscher (1955:29) found it locally common throughout the year
on the coast of Veracruz, and he mentioned seeing birds a short
distance south of Tampico in June and July. The status of this gull in
Tamaulipas remains to be determined; probably it will be found breeding
locally, but many of the birds summering in eastern México are most
likely nonbreeders (A.O.U. Check-list, 1957:226).

=_Chlidonias niger surinamensis_= (Gmelin): Black Tern.--On July 6, 7,
8, 9, and on the morning of July 10, we saw this species only
occasionally, recording in total not more than 50 individuals. But,
about noon on July 10, we observed at least 300 birds in compact flocks
of about 50 individuals each between Washington Beach and a point about
9 miles south of that locality. Approximately one in ten birds seen was
in breeding plumage, the rest being in winter or subadult plumages,
which are indistinguishable in the field. Perhaps some of the birds
seen were nonbreeding, summering individuals, but we presume that the
large groups were southbound migrants, and we note that autumnal
migrants appear in northern Veracruz as early as July 1 (Loetscher,
1955:30). On the central Gulf coast of Texas, Hagar and Packard
(1952:9) indicate that an influx of birds occurs in the last week of
July, and small numbers of birds, presumably nonbreeding individuals,
are present along the Gulf coast throughout June and July. Dresser
(1866:45) found this species to be "common at the Boca Grande during
the summer."

Specimens (2): [M], 38948, testis 6 mm., moderately fat, 68 gm., in
breeding plumage, Camp 1, July 7. Female, 38949, ovary inactive, 49
gm., molt into winter feather almost complete, Camp 2, July 10.

=_Hydroprogne caspia_= (Pallas): Caspian Tern.--The only published
record of the Caspian Tern in Tamaulipas is a report of one seen at
Lomas del Real on November 20, 1956 (Coffey, 1960:260), but we found it
moderately common all along the beach and at the margin of the laguna.
It was frequently associated with the Royal Tern, which outnumbered it
better than three to one (see Table 2). The species is resident and
breeds along the coast of Texas, and it probably has similar status in
Tamaulipas. However, in Veracruz it is known only as a winter visitant
(Loetscher, 1955:30) and as a spring migrant (Coffey, 1960:293).
Specimen: [F], 38950, ova to 2 mm., moderately fat, weight not
recorded, 5 P old, Camp 2, July 9.

=_Sterna hirundo hirundo_= Linnaeus: Common Tern.--We took a specimen
([M]?, 38951, no fat, 165 gm.), 49 miles south of Washington Beach on
July 8, and saw two others over the laguna at Camp 2 on July 9. Our
specimen had nearly finished with molt and feather growth into adult
winter plumage. The status of Common Terns in Tamaulipas is uncertain;
our record, and records from Tamós on July 1, 1952, and June 12, 1953
(Loetscher, 1955:29), probably pertain to nonbreeding, summering birds.
Yet, the species has bred on the Texas Gulf coast (A.O.U. Check-list,
1957:235), and it reasonably may be expected to nest in Tamaulipas.
Coffey (1960:293) saw two individuals at Altamira on May 10, 1954.

=_Sterna forsteri_= Nuttall: Forster Tern.--Six were recorded near Camp
1 on July 7, and two were seen on the beach on July 6 and 10. The
Mexican Check-list (1950:108) does not cite records for Tamaulipas, but
the A.O.U. Check-list (1957:234) includes northern Tamaulipas within
the breeding range. Evidence suggesting breeding of the species in
extreme northern Veracruz is reported by Loetscher (1955:29) in the
form of a female specimen with "ovary greatly enlarged" taken seven
miles west of Tampico on May 30, 1947. In the same area the species
also seems to spend the summer as a nonbreeder, for Loetscher (_loc.
cit._) saw 20, nearly all in nonbreeding plumage, on July 1, 1952.

Specimens (4): [M], 38952, testis 4.5 mm., 150 gm., 8 P old; [M],
38955, testis 2 mm., 138 gm., 2 P old; [M], 38953, testis 5 × 1 mm.,
142 gm., 5 P old; [F], 38954, ova to 1 mm., 148 gm., 2 P old; Camp 1,
July 7.

=_Sterna albifrons antillarum_= (Lesson): Least Tern.--The status of
this species in Tamaulipas is uncertain, but there is reason to
believe that it breeds, at least in small numbers. We found the species
moderately common and generally flying about in twos, possibly mated
pairs, near both camps and on the beach. Breeding is suggested by the
large sizes of the testes of the two males collected and by the
presence of brood patches on a female taken on July 6, but we have no
direct evidence of nesting in Tamaulipas, and it should be noted that
this species is known to spend the summer in nonbreeding condition at
many places (A.O.U. Check-list, 1957:239). Loetscher (1955:30) suggests
that the species may be found breeding in Veracruz and mentions a
record of 15 seen at Miramar, Tamaulipas, on June 26, 1952. Dresser
(1866:45) found it to be "abundant" at the "Boca Grande" in summer.

On July 10, we saw flocks of 15 to 20 individuals flying along the
beach a few miles south of Washington Beach.

Specimens (4): [M], 38958, testis 11 × 4 mm. (right testis 5 × 4 mm.),
light fat, 45 gm., 6 P old; [M], 38959, testis 11 × 4 mm. (right testis
7 × 4 mm.), light fat, 45 gm., 6 P old; [F], 38956, ova to 2.5 mm.,
42.5 gm., 6 P old, brood patches refeathering; Camp 1, July 6. Female,
38957, ova to 1 mm., 44 gm., Camp 1, July 7. This last specimen had
essentially completed the autumnal molt into winter plumage, with only
a few feathers remaining ensheathed basally.

Our specimens are referable to _S. a. antillarum_, being paler dorsally
and slightly lighter gray on the hind-neck than specimens of _S. a.
athalassos_ from Kansas, with which they were compared.

=_Thalasseus maximus maximus_= (Boddaert): Royal Tern.--This species
was common all along the beach, occurring for the most part in flocks
of from ten to 50 individuals in association with Cabot Terns. Data on
gonadal condition and brood patches of some of our specimens suggest
that breeding occurs in coastal Tamaulipas, as previously reported by
the Mexican Check-list (1950:110). Robins, Martin, and Heed (1951)
report seeing one Royal Tern near Tepehuaje on May 9, 1949, and Dresser
(1866:44) found the species "common at the Boca del Rio Grande during
the summer."

Specimens (6): [M], 38960, testis 9 × 4.5 mm., not fat, 484 gm., 6 P
old, brood patches refeathering, 4 miles south of Washington Beach,
July 6. Male, 38961, testis 7 × 3 mm., 455 gm., no brood patches, 8
miles south of Washington Beach, July 6. Male, 38962, testis 10 × 5
mm., 387 gm., brood patches refeathering; [F], 38963, ova to 1 mm., 358
gm., 3 P old; [F], 38964, ova to 3 mm., 389 gm., 8 P old; Camp 1, July
7. Female, 38994, ova to 2 mm., 536 gm., brood patches refeathering,
Camp 2, July 10.

=_Thalasseus sandvicensis acuflavidus_= (Cabot): Cabot Tern.--This tern
was moderately common along the beach and margin of the laguna, and it
was seen frequently in company with Royal Terns. Like the latter, this
tern breeds in coastal Texas (A.O.U. Check-list, 1957:241), and it
probably also nests in Tamaulipas, although direct evidence is not
available. The only previous record of this species in Tamaulipas is a
report (Robins, Martin, and Heed, 1951) of two observed on the beach
near Tepehuaje on May 9, 1949.

Specimens (4): [M], 38965, testis 9 × 4.5 mm., 208 gm., 9 P old, 49
miles south of Washington Beach, July 8. Male, 38966, testis 8 × 3 mm.,
not fat, 192 gm., 8 P old; [F], 38967, ova to 3 mm., 193 gm., 7 P old,
brood patches refeathering; [F], 38968, ova to 1 mm., 186 gm., 8 P old,
no brood patches; 52 miles south of Washington Beach, July 8.

=_Rynchops nigra nigra_= Linnaeus: Black Skimmer.--We found this
species moderately common at the edge of the laguna at both camps and
occasionally saw it along the beach. Generally two birds, probably
mated pairs, were seen together; twice birds were seen carrying food in
their bills, presumably intended for nestlings. The species is known to
nest in Tamaulipas from "Matamoros Lagoon" south to Tampico (Mexican
Check-list, 1950:112).

Specimens (2): [M], 38970, testis 40 × 23 mm. (abnormally large,
possibly as a result of hemorrhage), 418 gm., brood patches
refeathering; [M], 38969, testis 17 × 4 mm., fat light, 442 gm., brood
patches refeathering; Camp 1, July 7.

=_Zenaidura macroura_= Linnaeus: Mourning Dove.--Our only record is a
lone bird seen in a mesquite near Camp 1 on July 6. Possibly the
species breeds along the margin of the laguna, although Aldrich and
Duvall (1958:113, map) do not include coastal Tamaulipas in the known
breeding range. Loetscher (1955:30) suggests that the Mourning Dove may
be found breeding in the lowlands of northern Veracruz and cites a
record of one seen at Tamós on July 1, 1952.

=_Geococcyx californianus_= (Lesson): Road-runner.--At least four
individuals were seen in large dunes at Camp 1 on July 7 and 8. On
several occasions we watched them pursue lizards (_Holbrookia
propinqua_) at the margins of clumps of _Croton_ and _Ipomoea_.

=_Chordeiles minor aserriensis_= Cherrie: Nighthawk.--Nighthawks of
this species were seen regularly at Camp 1, where we flushed them from
alkaline flats in the day and heard them calling as they foraged over
the dunes in late afternoon.

Specimens (3): [M], 38971, testis 5 mm., no fat, 62 gm., Camp 1, July
6. Male, 38972, testis 7.5 mm., no fat, 58 gm.; [M], 38973, testis ?,
no fat, 53 gm.; Camp 1, July 7. The gonads of these birds were not in
full breeding condition, but it is highly probable that the birds were
members of a population that had bred in the area.

Variation in _Chordeiles minor_ in Tamaulipas has recently been studied
by Graber (1955). Two specimens taken by him on August 3, 1953,
approximately 9 miles south of Carbonera, resemble birds from Terrell
County, Texas, and represent _C. m. aserriensis_, as do our three birds
from the barrier island. Two of Graber's specimens from Lomas del Real,
in southeastern Tamaulipas, are distinctly darker and probably
represent _C. m. neotropicalis_, a subspecies subsequently described
from Chiapas (Selander and Alvarez del Toro, 1955).

=_Muscivora forficata_= (Gmelin): Scissor-tailed Flycatcher.--On July 7
near Camp 1, two individuals were found in stands of mesquite. One was
taken and proved to be an adult male (38974, testis 6 × 3 mm., not fat,
40 gm.) in postnuptial molt (6 P old).

We presume that the two birds recorded by us were members of a
population breeding on the barrier island, rather than autumnal
migrants. The Mexican Check-list (1957:69) records this species in
México only as a transient and winter visitant. But, on the basis of
records of birds seen along the highway between Matamoros and Ciudad
Victoria, Davis (1950) has suggested that the species breeds in
Tamaulipas, and this is supported by a report of one seen at the north
end of the Monterrey Airport on June 1, 1957 (Coffey, 1960:294). Brown
(1958) has recently established that the species breeds in Nuevo León
by finding a nest 33 kilometers (by road) north of Sabinas, Hidalgo, on
July 19, 1954.

=_Myiarchus cinerascens cinerascens_= (Lawrence): Ash-throated
Flycatcher.--A juvenal male (38975, testis 2 mm., no fat, 35.0 gm.)
taken in mesquite at Camp 1 constitutes our only record for this
species. Lanyon (1961:441, map) has shown that most of Tamaulipas is
devoid of these flycatchers in the breeding season; the nearest known
breeding Ash-throated Flycatchers are slightly west of Corpus Christi,
Texas, about 200 miles north-northwest of Camp 1 on the barrier beach.
Our specimen closely resembles eight specimens from Coahuila, México,
in general coloration and, especially, in the pattern of colors on the
outer rectrices. Probably No. 38975 was from southwestern Texas or
Coahuila and had begun its southward migration. Against this idea lies
chiefly the fact that young-of-the-year tend to move south later than
adults of the same species; so, this bird possibly had been reared in
coastal Tamaulipas.

=_Eremophila alpestris giraudi_= (Henshaw): Horned Lark.--This species
occurred in moderate numbers on alkaline flats and almost barren sand
flats at both camps. At the time of our visit to the island, the
breeding season apparently was coming to an end, but we noted no
tendency in the birds to flock.

Specimens (7): [M], 38981, testis 6 mm., 21.0 gm.; [M], 38977, testis
7.5 × 4 mm., not fat, 27.5 gm.; [M], 38979, testis 11 × 7 mm., 29.0
gm.; [F], 38976, ova to 3 mm., brood patch vascular but regressing, no
fat, 24.4 gm.; sex? juv., 38987, no fat, 21.0 gm.; sex? juv., 38980,
24.0 gm.; Camp 1, July 7. Male, 38982, testis 9.5 × 6 mm., 27.5 gm.,
Camp 2, July 9.

The subspecies _E. a. giraudi_, which is endemic to the Gulf coastal
plain of Texas and Tamaulipas, has been reported in Tamaulipas
previously only from Bagdad, near Matamoros (Mexican Check-list,
1957:106). The fact that our specimens show characters totally
consistent with those of _E. a. giraudi_ indicates that there is little
genetic interchange between the population we sampled and those of _E.
a. diaphora_, the closest of which reportedly breeds at Miquihana, in
southwestern Tamaulipas.

=_Corvus cryptoleucus_= Couch: White-necked Raven.--Several groups of
six to ten birds were present at Washington Beach on July 6 and 10;
but, southward on the island, we recorded this species only once, on
July 9, when a lone individual flew near Camp 2, being pursued and
"buzzed" by two Least Terns. The Mexican Crow (_Corvus imparatus_)
reportedly is common in the coastal region of Tamaulipas (Mexican
Check-list, 1957:118) but was not seen by us.

=_Thryomanes bewickii cryptus_= Oberholser: Bewick Wren.--This species
seemingly breeds in small numbers in mesquite stands near Camp 1, where
we obtained a juvenile and saw another individual. Specimen: [F] juv.,
38983, no fat, 10.0 gm., Camp 1, July 8. _T. b. cryptus_ is reported to
intergrade with _T. b. murinus_ of Veracruz in southern Tamaulipas
(Mexican Check-list, 1957:160-161).

=_Mimus polyglottos leucopterus_= (Vigors): Northern Mockingbird.--We
recorded this species only near Camp 1, where a few pairs were breeding
in stands of mesquite. Males were in full song and territorial display.

Specimens (2): [M], 38985, testis 11 × 7 mm., not fat, 43 gm.; [F],
38984, ova to 4.5 mm., vascular brood patch, 49.0 gm.; Camp 1, July 7.

PLATE 7

[Illustration: FIG. 1.--Mesquite-cactus formation on clay dune at
margin of the Laguna Madre west of Camp 1. Habitat of Northern
Mockingbird, Cardinal, Bob-white, black-tailed jackrabbit, and Great
Plains woodrat.]

[Illustration: FIG. 2.--_Batis-Monanthochloë_ formation on alkaline
flats near the Laguna Madre, with mesquite bordering stabilized dunes
in the left background. _Salicornia_, a classical dominant of salt
marshes, is here relatively inconspicuous. Habitat of Nighthawk and
Horned Lark.]

PLATE 8

[Illustration: "Fossilized" burrow of Texas Pocket Gopher in a sandy
trough between active dunes. A part of the cast has been broken away to
show the general shape of the old burrow. The diameter of the cast is
about 3.5 inches.]

=_Cassidix mexicanus prosopidicola_= Lowery: Great-tailed
Grackle.--Small, postbreeding flocks composed of both adult and juvenal
birds were seen moving along the edge of the laguna at Camp 1. In the
morning the flocks flew south, and in the afternoon groups of similar
size flew north, presumably to a roost at an undetermined distance
north of our camp. Occasionally, a few birds stopped to rest or to
forage on the dunes or in stands of mesquite. At Camp 2 on July 9, a
postbreeding adult female and a well-grown, presumably independent
juvenile were taken as they perched in a clump of mesquite in which we
found three old nests of _Cassidix_; two of the nests were about four
feet apart in one tree, and the third was in another tree 100 feet from
the first.

Specimens (4): [M] adult, 38988, testis 6 mm., no fat, 209 gm., 6 P
old, Camp 1, July 7. Female, 38989, ova to 3 mm., fat, 115 gm., old
brood patch, Camp 1, July 8. Female, 38990, ova to 1 mm., moderate fat,
107 gm., 7 P old, brood patch refeathering; [M] juv., 38991, testis 3 ×
1 mm., not fat, 172 gm., 6 P old; Camp 2, July 9.

TABLE 4.--MEASUREMENTS IN MILLIMETERS OF ADULT MALES OF CASSIDIX
MEXICANUS

=============+=========+=========+=========+===========+============
             |         |         |         |           | Weight in
   LOCALITY  |   No.   |  Wing   |  Tail   |  Tarsus   |   grams
-------------+---------+---------+---------+-----------+------------
Austin, Texas|17-137[1]|  184.3  |  203.8  |   46.38   | 225.6 June
             |         |(173-200)|(178-232)|(41.8-50.0)| (204-253)
             |         |         |         |           | 202.2 July
             |         |         |         |           | (195-207)
             |         |         |         |           |
San Patricio |    5    |  185.2  |  204.2  |   46.74   |   237.6
Co., Texas[2]|         |(182-188)|(190-219)|(45.1-50.2)| (228-245)
             |         |         |         |           |
Barrier Is., |         |         |         |           |
Tamps.       |    1    |  178    |  185    |   47.1    |   209
             |         |         |         |           |
Victoria,    |    4    |  192.2  |  224.2  |   47.77   |   254.3
Tamps.[3]    |         |(186-200)|(215-232)|(46.0-49.1)| (239-276)
             |         |         |         |           |
Tampico,     |         |         |         |           |
Tamps.[4]    |    1    |  197    |  214    |   48.3    |   260
             |         |         |         |           |
Catemaco,    |         |         |         |           |
Veracruz[5]  |    1    |  193    |  216    |   48.2    |   257
-------------+---------+---------+---------+-----------+------------

[Footnote 1: Data from Selander (1958: 370, 373). Sample sizes, as
follows: wing, 137; tail, 119; bill length, 20 (June and July); tarsus,
133; weight, 17 for June, 3 for July.]

[Footnote 2: June 13, 1961; breeding condition.]

[Footnote 3: May 6, 1961; breeding condition.]

[Footnote 4: May 7, 1961; breeding condition.]

[Footnote 5: November 28, 1959.]

Specimens from the barrier island are clearly referable to _C. m.
prosopidicola_, showing no approach to the larger and, in the female,
darker _C. m. mexicanus_ of Veracruz and San Luis Potosí. In Table 4,
measurements of the adult male from the barrier island may be compared
with those of specimens of _C. m. prosopidicola_ from Texas and a
specimen of _C. m. mexicanus_ from Veracruz; it is apparent that our
specimen is assignable to the former.

Evidence of intergradation between the two subspecies is shown in a
series of birds collected near Ciudad Victoria, Tamaulipas, in May,
1961. The females in the series are highly variable in color
individually, but are on the average paler than _C. m. mexicanus_ from
Veracruz; the males are distinctly larger than _C. m. prosopidicola_
from Texas. At Miramar, near Tampico, Tamaulipas, a decided approach to
_C. m. mexicanus_ is also evident in the dark color of females and in
the large size of both males (Table 4) and females.

=_Agelaius phoeniceus megapotamus_= Oberholser: Red-winged
Blackbird.--This species was recorded only at Camp 1 on July 7, when we
saw two males, one of which was flying south along the edge of the
dunes in a flock of five Great-tailed Grackles. Specimen: [M], 38992,
testis 10 × 7 mm., fat, 54 gm., Camp 1, July 7. The large size of the
testes of this individual indicates breeding condition.

=_Sturnella magna hoopesi_= Stone: Eastern Meadowlark.--Meadowlarks
were found in small numbers along the margins of the alkaline flats at
both camps. Breeding was still in progress, for males were singing and
a female shot on July 9 had only recently laid eggs. Specimens (2):
[M], 38986, testis 13 × 8 mm., not fat, 102 gm.; [F], 38987, ova to 6
mm., 3 collapsed follicles, not fat, 88 gm.; Camp 2, July 9.

=_Richmondena cardinalis canicaudus_= Chapman: Cardinal.--This species
was recorded only in stands of mesquite near Camp 1, as follows: July
7, two pairs seen, from which a breeding female was taken; July 8,
three birds seen. Specimen: [F], 38933, edematous brood patch, 36.5
gm., Camp 1, July 7. Intergrades between the present subspecies and _R.
c. coccinea_ of Veracruz are reported from Altamira, Tamaulipas
(Mexican Check-list, 1957:329).


_Mammals_

=_Dasypus novemcinctus mexicanus_= Peters: Nine-banded
Armadillo.--Remains of an armadillo (89017) were found in a mesquite
thicket in the dunes near Camp 1 on July 7. The bones are not badly
weathered and were not embedded in sand.

This species has not been recorded previously on the barrier island of
Tamaulipas, nor, for that matter, on any of the barrier islands on the
western shore of the Gulf of Mexico.

=_Lepus californicus merriami_= Mearns: Black-tailed Jackrabbit.--From
two to four individuals were recorded daily in dunes and on alkaline
flats in the vicinity of stands of mesquite and cactus.

Specimens (2): [F] adult, 89018, pregnant (two embryos, 28 mm. in
crown-rump length), Camp 1, July 6. Male immature, 89019, Camp 1, July
7. Our specimens have been compared with two skins of _L. c. curti_
from the type locality at Eighth Pass, with which they agree reasonably
well in color. The size of the adult female is about that
characteristic of other specimens of adult _L. c. curti_, but
characters of the skull are consistent with those of _L. c. merriami_.

A specimen of this species from Matamoros and several from Brownsville,
Texas, have been assigned by Hall (1951:43) to _L. c. merriami_.
Specimens from Padre Island, Texas, reportedly resemble _L. c. curti_
in smallness of the tympanic bullae but are in other characters
referable to _L. c. merriami_ (Hall, 1951:44).

=_Spermophilus spilosoma annectens_= (Merriam): Spotted Ground
Squirrel.--These squirrels were moderately common in dunes at both
camps. They were heard calling, and many tracks and holes were seen. On
July 7, at Camp 1, a lactating, adult female (89020) and two dependent
juveniles (89021, skull only, 89022, skin and skull) were shot at the
entrance of a burrow; the uterus of the adult showed six placental
scars.

Our adult specimen has been compared with ten specimens obtained by
Hall and von Wedel at Eighth Pass in March, 1950; ours differs from the
ten in being paler and slightly larger. The pallor is perhaps
attributable to seasonal variation, and the size (246-79-38-7; weight,
133 gm.) is within limits that would be expected in a larger series of
the population sampled by Hall and von Wedel. Hall (1951:38) referred
specimens of this squirrel from Eighth Pass to _S. s. annectens_.

=_Geomys personatus personatus_= True: Texas Pocket Gopher.--This
pocket gopher was abundant on low, stabilized dunes on the barrier
island from four to 73 miles south of Washington Beach. One of us
(Wilks) made a trip down the beach on May 20 and 21, 1961, and
collected specimens at localities four miles south and 33 miles south
of Washington Beach; additional specimens were taken at both Camp 1 and
Camp 2 from July 6 to 10. At these localities the gophers seemed to
maintain population densities approximating those of _G. personatus_
on Padre and Mustang islands on the Texan coast.

There is but one other record of the Texas Pocket Gopher from México.
Goldman (1915) described _G. p. tropicalis_ from Altamira on the basis
of specimens collected in 1898. Since that time, the species has not
been reported as occurring south of Cameron County, Texas (Kennerly,
1954), some 50 miles northwest of the closest station of occurrence of
the gophers on the barrier beach of Tamaulipas.

Our specimens are slightly smaller than _G. p. personatus_ and slightly
larger than _G. p. megapotamus_, the subspecies of nearest geographic
occurrence to the barrier island. The degree to which our specimens
differ in other respects, such as configuration of the pterygoid, is
being studied further by Wilks. For the present, reference of our
material to the nominate subspecies best expresses the relationships of
these coastal gophers.

The fact that pocket gophers from the Tamaulipan barrier island occupy
a position geographically intermediate between present Texan
populations and the isolated population in southern Tamaulipas (_G. p.
tropicalis_) helps explain the origin of the latter. It is likely that
_G. p. tropicalis_ represents the southern remnant of a once
continuously-distributed population of pocket gophers living in coastal
Tamaulipas in mid-Wisconsin to late Wisconsin time. At that time, sea
level is thought to have been considerably lower than at present,
exposing a sandy strip 80 to 100 miles wide off the present coastline.
Presumably this would have been an area suitable for gophers and for
southward dispersal of individuals from Texas. The only conceivable
barrier to dispersal, and thus to a panmictic population, would have
been the Rio Grande, but over the wide, low and sandy coastal plain the
river channel almost certainly shifted regularly, thus decreasing its
effectiveness as a barrier to movement. With subsequent rise in sea
level, the gophers at Altamira became isolated and have presumably
remained so for a considerable time. To judge by the marked morphologic
differentiation of _G. p. tropicalis_, its degree of isolation from
other populations has been much greater than those of populations
inhabiting the Tamaulipan barrier island and the barrier islands of the
coast of Texas. Contact between the latter two populations was probably
fairly regular before man's stabilization of the channel of the
lowermost reaches of the Rio Grande.

At Camp 1 we found evidence of the former occurrence of gophers in an
area now largely covered by active beach dunes. Numerous skeletal parts
of gophers and "fossilized" burrows (Plate 8) were found on the surface
where troughs between active dunes reached down to an older, darker,
and more tightly cemented layer of sand underlying the present dunes.
It is clear that these gophers were not transported there, because the
bones were not damaged, some of the skeletons were almost complete, and
many of the bones were found near the "fossilized" burrows. Weathered
but well preserved skeletal remains of at least 12 gophers were picked
up at this site.

Specimens (17): [F], 89023, Camp 1, May 20. 4 [F] [F], 89024-026,
89029; 3 [M] [M], 89027, 89028, 89030; Camp 1, May 21. Male, 89031,
Camp 1, July 6. Three [M] [M], 89032, 89035, 89038; 4 [F] [F], 89033,
89034, 89036, 89037; Camp 2, July 9. Female, 89039, Camp 2, July 10.

=_Perognathus merriami merriami_= Allen: Merriam Pocket Mouse.--An
individual taken in a trap in the dunes near Camp 2 constitutes the
first record of this species from the barrier island of Tamaulipas.
This pocket mouse seems to be uncommon on other barrier islands of the
western Gulf of Mexico, for there is only one published report of its
occurrence on Padre Island, Texas (Bailey, 1905:141). Other nearby
stations of occurrence are Altamira, Tamaulipas (Hall and Kelson,
1960:477), Brownsville, Texas (Bailey, _loc. cit._), and 17 miles
northwest of Edinburg, Texas (Blair, 1952:240).

Specimen: sex?, 89040, skull only, Camp 2, July 10.

=_Dipodomys ordii parvabullatus_= Hall: Ord Kangaroo Rat.--We found
this species uncommon and confined in distribution to dunes, in which
it was recorded as follows: an adult female was shot and two other
individuals were seen at night on July 6 at Camp 1; three were trapped
near Camp 1 on July 7; two were trapped at Camp 2 on July 10.

Specimens (5): [F], 89041, 2 placental scars, 46 gm., Camp 1, July 6.
Male, 89042, testes scrotal, 47 gm.; [M], 89044, 60 gm.; [F], 89043, 44
gm.; Camp 1, July 7. Sex?, 89045, skel. only, Camp 2, July 10.

Our material does not differ significantly from specimens obtained by
Hall and von Wedel at Boca Jésus María in March, 1950, which formed the
basis for Hall's description (1951:41) of _D. o. parvabullatus_. This
subspecies is presumably confined in distribution to the barrier island
of Tamaulipas. Two immature specimens from Bagdad, Tamaulipas, were
tentatively assigned by Hall (1951:41) to _D. o. compactus_, a
subspecies known otherwise only from Padre Island, Texas.

=_Neotoma micropus micropus_= Baird: Southern Plains Woodrat.--This
species was noted only near Camp 1, where numerous houses were seen in
stands of mesquite and prickly-pear cactus and an adult male (89046,
330 gm.) was taken on July 6. This species has not been reported
previously from the barrier island of Tamaulipas. Our specimen is
referable to the nominate subspecies and shows no approach to _N. m.
littoralis_, a subspecies known only from the type locality at
Altamira, Tamaulipas (see map, Hall and Kelson, 1960:684).

=_Procyon lotor_= (Linnaeus): Raccoon.--A weathered skull and a broken
humerus were found at Camp 2. The skull is being studied by Dr. E. L.
Lundelius, who informs us that it matches a number of raccoon skulls
found in archaeological sites along the Balcones Escarpment of Texas.
Such skulls are larger than skulls of raccoons occurring today in Texas
(_P. l. fuscipes_) and closely resemble skulls of raccoons (_P. l.
excelsus_) presently confined in distribution to Idaho, eastern Oregon,
and eastern Washington. Further details of this situation are to be
reported elsewhere by Lundelius.

=_Taxidea taxus_= (Schreber): Badger.--Two burrows were found in the
stabilized dunes near Camp 1, tracks were noted on the alkaline flats,
and a weathered skull (89047) was found on the flats west of Camp 1 on
July 7. The skull appears to be of an immature animal, for the sutures
are not well closed and the teeth show little wear.

Our records require an extension of known range of this species
southeasterly by approximately 50 miles. The only previous record in
coastal Tamaulipas is based on two skulls from Matamoros (Schantz,
1949:301). The skull from the barrier island cannot be determined to
subspecies but on geographic grounds is referable to _T. t.
littoralis_, with type locality at Corpus Christi, Texas.

=_Canis_= sp.--Numerous tracks made either by Coyotes (_C. latrans_
Say) or by domestic dogs were seen in dunes and on the beach at both
camps. A weathered, posterior part of a canid skull was found in dunes
at Camp 2 on July 10, and a partial left mandible was taken on the
beach at Camp 1 on July 6. Unfortunately, specific identification of
the skull fragments is not possible, but the few reasonably good
characters that we can use suggest that our material is of domestic
dogs rather than of Coyotes. Hall (1951:37) found tracks and other
signs of Coyotes at Eighth Pass but did not take specimens.

Most of the canid scats examined by us contained remains of crabs and
fishes.

=_Odocoileus virginianus_= (Boddaert): White-tailed Deer.--A weathered
Recent fragment of a mandible (89048) and part of a femur (89049) of
this species were found near Camp 1 on July 7, and a metapodal was
picked up in the dunes at Camp 2 on July 9. This species has not been
reported previously on the barrier island of Tamaulipas and it probably
no longer occurs there, for we saw no tracks or other signs of it. Hall
(1951) did not find it at Eighth Pass.

Our specimens probably pertain to _O. v. texanus_ but are possibly of
_O. v. veraecrucis_, which has been reported from Soto la Marina
(Goldman and Kellogg, 1940:89).

The only species of mammal known from the barrier island of Tamaulipas
that we did not find is the Hispid Cotton Rat (_Sigmodon hispidus_).
Two specimens of this species trapped near Eighth Pass in March, 1950,
formed the basis for the description of _S. h. solus_ (Hall, 1951:42),
a subspecies known only from the type locality.




Discussion


The known vertebrate fauna of the barrier island of Tamaulipas consists
of one species of tortoise, two species of lizards, at least one
(unidentified) species of snake, 49 species of birds (48 recorded by us
and the Semipalmated Sandpiper), and 12 species of mammals. This is
clearly a depauperate fauna, such as is characteristic of islands
generally, and indicates that the peninsular nature of the northern
part of the barrier island is of relatively small consequence in
determining presence or absence of species. It is likely that the
restricted environmental spectrum is much more important in this regard
than is the fact of semi-isolation.

Of the 49 species of birds, 10 are known to breed on the island and an
additional 21 are suspected of breeding either on the island or on
small islets in the adjacent Laguna Madre de Tamaulipas. Eleven species
occur on the island as nonbreeding summer residents, about which we
will have more to say below. Four species have been recorded on the
island in summer but breed elsewhere, that is to say, they only wander
over the island (Man-o'-war Bird, Turkey Vulture, _etc._). Two species
are known only as migrants, and the status of one, the Sora Rail, is
uncertain. The number of migrant species doubtless will be greatly
increased by field work at those times when birds migrate.

The avifauna is not depauperate owing to the exclusion of any one of
the three major zoogeographic stocks thought to be important in the
development of the present North American avifauna (Mayr, 1946). If we
examine the breeding passerine birds of the barrier island and the
breeding passerine assemblage at the same latitude in lowland Sonora
(Mayr, _loc. cit._) as to their ultimate evolutionary sources, we find
that for both places somewhat more than half the birds have developed
from indigenous, North American stocks, about one-third have been
derived from South American stocks, and one-fifth to one-eighth are
from Eurasian stocks. It is most unlikely that such close
correspondence in relative composition of the two avifaunas would occur
by chance. Thus, we can only conclude that each of the historical avian
stocks is proportionately restricted in numbers on the barrier island.

Faunistically, the barrier island resembles Padre and Mustang islands
and the adjacent mainland of Tamaulipas and southern Texas, reflecting
the relative uniformity of environment in this region. It is apparent
that there is a faunal "break" or region of transition in the vicinity
of Tampico, in extreme southeastern Tamaulipas. On the coastal plain,
many tropical species and subspecies occurring in Veracruz are found
north to Tampico but fail to extend farther northward to the barrier
island of northeastern Tamaulipas. Axtell and Wasserman (1953:4-5),
have already commented on this situation, mentioning a number of snakes
and lizards that have differentiated subspecifically on opposing sides
of the Tampican region. They also note that large numbers of the
lowland Neotropical floral and faunal elements reach their northern
limits of distribution within the zone of transition around Tampico,
and, also, many Nearctic elements find their southern distributional
limits there.

Our small samples of birds and reptiles from the island show no
detectable morphological differentiation from adjacent populations.
However, several of the mammals are moderately-well differentiated, but
the patterns and degrees of geographic variation are such that we can
only speculate on the historical derivation of the insular populations.
_Lepus californicus curti_ is presently known only from the barrier
island of Tamaulipas, but Hall (1951:43) has suggested that it may also
occur on the adjacent mainland. A resemblance between individuals of
this subspecies and specimens of _L. c. merriami_ from Padre Island in
smallness of the tympanic bullae is regarded, probably correctly, by
Hall (1951:44) as independent development--that is, parallel
adaptation to similar environmental conditions reaching fullest
expression on the barrier island of Tamaulipas. As is also true with
_Geomys personatus_ and _Neotoma micropus_, the barrier island
population of _Lepus californicus_ shows relationships with animals
from Texas and northern Tamaulipas (_L. c. merriami_) and no connection
with (resemblance to) animals from the south (_L. c. altamirae_, known
only from the type locality at Altamira, near Tampico).

In color and cranial proportions, _Dipodomys ordii parvabullatus_ of
the barrier island is closer to _D. o. compactus_ of Padre Island than
to _D. o. sennetti_ of southern Texas and the Tamaulipan mainland. But,
_D. o. parvabullatus_ resembles _D. o. sennetti_ in external
measurements (Hall, 1951:39). Possibly _D. o. parvabullatus_ and _D. o.
compactus_ are phylogentically closer to one another than is either to
_D. o. sennetti_. It is also possible that each evolved independently
from a mainland stock represented today by _D. o. sennetti_; the
resemblance of the two insular populations would thus be a matter of
convergence in response to like environmental conditions.

_Sigmodon hispidus solus_ is an insular differentiate that probably
reached the barrier island from the adjacent mainland of Tamaulipas,
where its apparent closest relative, as judged by morphological
similarity, now occurs.

_Nonbreeding shorebirds in summer south of breeding ranges._--Certain
aspects of this subject have already been discussed by Eisenmann
(1951). As he notes, the phenomenon is more regular and widespread than
generally has been appreciated. The old idea, that such oversummering
individuals were "abnormal" or "senile," is totally inadequate,
especially in view of the frequently large numbers of individuals
involved.

Eisenmann's suggestion that nonbreeders are immature is probably valid,
and it is supported by Pitelka's examination of dowitchers (1950:28,
51). For gulls, which can be aged by characters of plumage, there is no
question that most nonbreeders are immature. Unfortunately, there are
few criteria for determination of age in charadriiform birds.

With the possible exception of a specimen of _Limosa fedoa_, none of
the presumed nonbreeding, oversummering shorebirds collected by us
showed gonadal enlargement above expected minimal sizes for the
species. Even so, the season was late at the time when we were on the
island and most of the birds were molting; it is possible their gonads
had been enlarged earlier in the season. Behle and Selander (1953) and
Johnston (1956) have shown that nonbreeding first-, second-, and
third-year California Gulls (_Larus californicus_) undergo gonadal
enlargement in summer. Additionally, nonbreeding first-year males of
certain passerine species (for example, the Brown Jay, _Psilorhinus
morio_; Selander, 1959) are known to experience partial gonadal
recrudescence in summer. It would be useful, and would facilitate
discussion, to have data on gonadal condition of oversummering birds;
any functional enlargement would be worth documenting.

Some species, notably the Semipalmated Sandpiper, Semipalmated Plover,
and Black Tern, oversummer as nonbreeders in such large numbers that it
is obvious that a significant fraction of the total population of the
species does not breed in any one year. This raises questions
concerning the possible ecologic situations that would select for delay
in time of recruitment of young birds into the breeding segment of the
population, assuming that nonbreeders are immature birds. Delay in
maturation, or slow rates of maturation, may show general relationship
to paucity of sites of breeding, as Orians (1961:308) suggests, but the
shorebirds with which we are dealing breed in regions or in
habitat-types not characteristically imposing general restriction on
sites of nesting; more than one answer is necessary for the question
even at this level. Data on age and numbers of nonbreeders, as well as
on the ecology of breeding populations, are critical and are badly
needed for most species.

In any event, species for which we have data demonstrating that they
regularly oversummer south of their breeding ranges are probably
adapted to having a part of their populations refrain from breeding
each year. Whether this phenomenon can be explained solely in terms of
selection at the level of individual birds (Lack, 1954) or involves
selection of an adaptive response of the population as a whole
(Wynne-Edwards, 1955; see also Taylor, 1961, concerning _Rattus_) is a
problem that cannot be resolved at this time. We may note that the
species involved ordinarily breed in arctic and subarctic regions, and
it would seem advantageous (as set forth below) for nonbreeders to
remain well south of such high latitudes. The numbers of oversummering
individuals may fluctuate with over-all population density, possibly as
a result of crude density, but possibly also as a result of emigration
of individuals in excess of optimal density on breeding grounds (see
Wynne-Edwards, 1959). One aspect of this phenomenon not explicitly
discussed by Wynne-Edwards is the possibility that some individuals
never move north to breeding grounds at all, perhaps as a result of a
behavioral character genetically-grounded and mediated by delayed
maturation of the neurohumoral "clock." This certainly would be an
economical means by which population numbers could be regulated, for
there would be a saving of energy in that some individuals not only
would not move north, but also would not participate in the behavioral
interactions involved in territorial spacing. Occurrence of these birds
throughout southern North America, Middle America, and northern South
America may thus reasonably be understood.




LITERATURE CITED


ALDRICH, J. W., and DUVALL, A. J.

     1958. Distribution and migration of races of the mourning
     dove. Condor, 60:108-128.

AMADON, D., and ECKELBERRY, D. R.

     1955. Observations on Mexican birds. Condor, 57:65-80.

AMERICAN ORNITHOLOGISTS' UNION CHECK-LIST COMMITTEE

     1957. Check-list of North American Birds. Lord Baltimore
     Press, Baltimore, Maryland. xiii-691 pp.

AXTELL, R. W.

     1954. The systematic relationships of certain lizards in two
     species groups of the genus _Holbrookia_. M. A. Thesis,
     Department of Zoology, Univ. Texas. 55 pp.

AXTELL, R. W., and WASSERMAN, A. O.

     1953. Interesting herpetological records from southern Texas
     and northern Mexico. Herpetologica, 9:1-6.

BAILEY, V.

     1905. Biological survey of Texas. North Amer. Fauna,
     25:1-222.

BAKER, R. H., and LAY, D. W.

     1938. Notes on the mammals of Galveston and Mustang islands,
     Texas. Jour. Mammal., 19:505.

BEHLE, W. H., and SELANDER, R. K.

     1953. The plumage cycle of the California gull (_Larus
     californicus_) with notes on color changes of soft parts.
     Auk, 70:239-260.

BLAIR, W. F.

     1952. Mammals of the Tamaulipan Biotic Province in Texas.
     Texas Jour. Sci., 4:230-250.

BROWN, J. L.

     1958. A nesting record of the scissor-tailed flycatcher in
     Nuevo León, México. Condor, 60:193-194.

COFFEY, B. B., JR.

     1960. Late North American spring migrants in Mexico. Auk,
     77:288-297.

DAVIS, W. B.

     1950. Summer range of the scissor-tailed flycatcher. Condor,
     52:138.

DRESSER, H. E.

     1865-1866. Notes on the birds of southern Texas. Ibis,
     1865:312-330; 446-495. Ibis, 1866:23-46.

EISENMANN, E.

     1951. Northern birds summering in Panama. Wilson Bull.,
     62:181-185.

GOLDMAN, E. A.

     1915. Five new mammals from Mexico and Arizona. Proc. Biol.
     Soc. Washington, 28:133-138.

     1951. Biological investigations in Mexico. Smithsonian Misc.
     Coll., no. 4017, 476 pp.

GOLDMAN, E. A., and KELLOGG, R. R.

     1940. Ten new white-tailed deer from North and Middle
     America. Proc. Biol. Soc. Washington, 53:81-89.

GRABER, R. R.

     1955. The nighthawks of the Tamaulipas coast of México.
     Condor, 57:125-126.

GRABER, R. R., and GRABER, J. W.

     1954_a_. Yellow-headed vulture in Tamaulipas, México.
     Condor, 56:165-166.

     1954_b_. Comparative notes on Fuertes and orchard orioles.
     Condor, 56:274-282.

HAGAR, C. N., and PACKARD, F. M.

     1951. Checklist of the birds of the central coast of Texas.
     (Privately printed by the authors.)

HALL, E. R.

     1951. Mammals obtained by Dr. Curt von Wedel from the
     barrier beach of Tamaulipas, Mexico. Univ. Kansas Publ.,
     Mus. Nat. Hist., 5:33-47.

HALL, E. R., and KELSON, K.

     1960. The mammals of North America. Ronald Press, New York.
     xxx + 1083 pp.

HAVERSCHMIDT, F.

     1955. North American shore birds in Surinam. Condor,
     57:366-368.

HEDGPETH, J. W.

     1947. The Laguna Madre of Texas. Trans. Twelfth North Amer.
     Wildl. Conf., 364-380.

     1953. An introduction to the zoogeography of the
     northwestern Gulf of Mexico with reference to the
     invertebrate fauna. Publ. Inst. Marine Sci., Univ. Texas,
     3:111-224.

HELLMAYR, C. E., and CONOVER, B.

     1948. Catalogue of birds of the Americas.... Field Mus. Nat.
     Hist., Publ. 615, Zool. Ser., 13 (1), no. 2:vii + 434 pp.

HILDEBRAND, H. H.

     1958. Estudios biológicos preliminares sobre La Laguna Madre
     de Tamaulipas. Ciencia (Mex.), 17:151-173.

KENNERLY, T. E., JR.

     1954. Local differentiation in the pocket gopher (_Geomys
     personatus_) in southern Texas. Texas Jour. Sci., 6:297-329.

JOHNSTON, D. W.

     1956. The annual reproductive cycle of the California gull.
     Condor, 58:138-162; 206-221.

LACK, D.

     1954. The natural regulation of animal numbers. Clarendon
     Press, Oxford. viii + 343 pp.

LOETSCHER, F. W., JR.

     1955. North American migrants in the state of Veracruz,
     Mexico: a summary. Auk, 72:14-54.

MAYR, E.

     1946. History of the North American bird fauna. Wilson
     Bull., 58:3-41.

MEYERRIECKS, A. J.

     1960. Comparative breeding behavior of four species of North
     American herons. Publ. Nuttall Ornith. Club, no. 2:158 pp.

MEXICAN CHECK-LIST

     1950. Distributional check-list of the birds of Mexico. Part
     I. Pac. Coast Avif., 29:202 pp.

     1957. Distributional check-list of the birds of Mexico.
     Part. II. Pac. Coast Avif., 33:436 pp.

ORIANS, G. H.

     1961. The ecology of blackbird (_Agelaius_) social systems.
     Ecol. Monogr., 31:285-312.

PAYNTER, R. A., JR.

     1955. The ornithogeography of the Yucatán peninsula. Peabody
     Mus. Nat. Hist., Bull. 9:347 pp.

PETERSON, R. T.

     1960. A field guide to the birds of Texas. Houghton Mifflin
     Co., Boston. 304 pp.

PITELKA, F. A.

     1950. Geographic variation and the species problem in the
     shore-bird genus _Limnodromus_. Univ. California Publ.
     Zool., 50:1-108.

PRICE, W. A.

     1933. Role of diastrophism in topography of Corpus Christi
     area, south Texas. Bull. Amer. Assoc. Petrol. Geol.,
     17:907-962.

ROBINS, C. R., MARTIN, P. S., and HEED, W. B.

     1951. Frigate-bird, oystercatcher, upland plover and various
     terns on the coast of Tamaulipas, México. Wilson Bull.,
     63:336.

SELANDER, R. K.

     1958. Age determination and molt in the boat-tailed grackle.
     Condor, 60:355-376.

     1959. Polymorphism in Mexican brown jays. Auk, 76:385-417.

SELANDER, R. K., and ALVAREZ DEL TORO, M.

     1955. A new race of booming nighthawk from southern Mexico.
     Condor, 57:144-147.

SHANTZ, V. S.

     1949. Three new races of badgers (_Taxidea_) from
     southwestern United States. Jour. Mammal., 30:301-305.

SMITH, H. M.

     1946. Handbook of lizards. Comstock Publ. Co., Ithaca, New
     York. 557 pp.

SUTTON, G. M.

     1950. The southern limits of the willet's continental
     breeding range. Condor, 52:135-136.

TAYLOR, J. M.

     1961. Reproductive biology of the Australian bush rat Rattus
     assimilis. Univ. California Publ. Zool., 60:1-66.

THOMPSON, M. C.

     1958. Semipalmated sandpiper from Tamaulipas. Wilson Bull.,
     70:288.

WYNNE-EDWARDS, V. C.

     1955. Low reproductive rates in birds, especially sea-birds.
     Acta XI Internat. Ornith. Congr., 540-547.

     1959. The control of population-density through social
     behaviour: a hypothesis. Ibis, 101:436-441.

_Transmitted March 15, 1962._

29-3602




UNIVERSITY OF KANSAS PUBLICATIONS MUSEUM OF NATURAL HISTORY


Institutional libraries interested in publications exchange may obtain
this series by addressing the Exchange Librarian, University of Kansas
Library, Lawrence, Kansas. Copies for individuals, persons working in a
particular field of study, may be obtained by addressing instead the
Museum of Natural History, University of Kansas, Lawrence, Kansas.
There is no provision for sale of this series by the University
Library, which meets institutional requests, or by the Museum of
Natural History, which meets the requests of individuals. However, when
individuals request copies from the Museum, 25 cents should be
included, for each separate number that is 100 pages or more in length,
for the purpose of defraying the costs of wrapping and mailing.

* An asterisk designates those numbers of which the Museum's supply
(not the Library's supply) is exhausted. Numbers published to date, in
this series, are as follows:

 Vol.  1. Nos. 1-26 and index. Pp. 1-638, 1946-1950.

*Vol.  2. (Complete) Mammals of Washington. By Walter W. Dalquest.
           Pp. 1-444, 140 figures in text. April 9, 1948.

 Vol.  3. *1. The avifauna of Micronesia, its origin, evolution,
              and distribution. By Rollin H. Baker, Pp. 1-359, 16
              figures in text. June 12, 1951.

          *2. A quantitative study of the nocturnal migration of
              birds. By George H. Lowery, Jr. Pp. 361-472, 47
              figures in text. June 29, 1951.

           3. Phylogeny of the waxwings and allied birds. By M.
              Dale Arvey. Pp. 473-530, 49 figures in text, 13
              tables. October 10, 1951.

           4. Birds from the state of Veracruz, Mexico. By George
              H. Lowery, Jr., and Walter W. Dalquest. Pp. 531-649,
              7 figures in text, 2 tables. October 1, 1951.

           Index. Pp. 651-681.

*Vol.  4. (Complete) American weasels. By E. Raymond Hall. Pp. 1-466,
          41 plates, 31 figures in text. December 27, 1951.

 Vol.  5. Nos. 1-37 and index. Pp. 1-676, 1951-1953.

*Vol.  6. (Complete) Mammals of Utah, _taxonomy and distribution_.
          By Stephen D. Durrant. Pp. 1-549, 91 figures in text,
          30 tables. August 10, 1952.

 Vol.  7. *1. Mammals of Kansas. By E. Lendell Cockrum. Pp. 1-303,
              73 figures in text, 37 tables. August 25, 1952.

           2. Ecology of the opossum on a natural area in
              northeastern Kansas. By Henry S. Fitch and Lewis L.
              Sandidge. Pp. 305-338, 5 figures in text. August
              24, 1953.

           3. The silky pocket mice (Perognathus flavus) of Mexico.
              By Rollin H. Baker. Pp. 339-347, 1 figure in text.
              February 15, 1954.

           4. North American jumping mice (Genus Zapus). By Phillip
              H. Krutzsch. Pp. 349-472, 47 figures in text, 4
              tables. April 21, 1954.

           5. Mammals from Southeastern Alaska. By Rollin H. Baker
              and James S. Findley. Pp. 473-477. April 21, 1954.

           6. Distribution of Some Nebraskan Mammals. By J. Knox
              Jones, Jr. Pp. 479-487. April 21, 1954.

           7. Subspeciation in the montane meadow mouse, Microtus
              montanus, in Wyoming and Colorado. By Sydney
              Anderson. Pp. 489-506, 2 figures in text. July 23,
              1954.

           8. A new subspecies of bat (Myotis velifer) from
              southeastern California and Arizona. By Terry A.
              Vaughan. Pp. 507-512. July 23, 1954.

           9. Mammals of the San Gabriel mountains of California.
              By Terry A. Vaughan. Pp. 513-582, 1 figure in text,
              12 tables. November 15, 1954.

          10. A new bat (Genus Pipistrellus) from northeastern
              Mexico. By Rollin H. Baker. Pp. 583-586. November
              15, 1954.

          11. A new subspecies of pocket mouse from Kansas. By
              E. Raymond Hall. Pp. 587-590. November 15, 1954.

          12. Geographic variation in the pocket gopher, Cratogeomys
              castanops, in Coahuila, Mexico. By Robert J. Russell
              and Rollin H. Baker. Pp. 591-608. March 15, 1955.

          13. A new cottontail (Sylvilagus floridanus) from
              northeastern Mexico. By Rollin H. Baker. Pp.
              609-612. April 8, 1955.

          14. Taxonomy and distribution of some American shrews.
              By James S. Findley. Pp. 613-618. June 10, 1955.

          15. The pigmy woodrat, Neotoma goldmani, its distribution
              and systematic position. By Dennis G. Rainey and
              Rollin H. Baker. Pp. 619-624, 2 figures in text.
              June 10, 1955.

          Index. Pp. 625-651.

 Vol. 8.  Nos. 1-10 and index. Pp. 1-675, 1954-1956.

 Vol. 9.   1. Speciation of the wandering shrew. By James S.
              Findley. Pp. 1-68, 18 figures in text. December 10,
              1955.

           2. Additional records and extension of ranges of mammals
              from Utah. By Stephen D. Durrant, M. Raymond Lee,
              and Richard M. Hansen. Pp. 69-80. December 10, 1955.

           3. A new long-eared myotis (Myotis evotis) from
              northeastern Mexico. By Rollin H. Baker and Howard
              J. Stains. Pp. 81-84. December 10, 1955.

           4. Subspeciation in the meadow mouse, Microtus
              pennsylvanicus, in Wyoming. By Sydney Anderson.
              Pp. 85-104, 2 figures in text. May 10, 1956.

           5. The condylarth genus Ellipsodon. By Robert W. Wilson.
              Pp. 105-116, 6 figures in text. May 19, 1956.

           6. Additional remains of the multituberculate genus
              Eucosmodon. By Robert W. Wilson. Pp. 117-123, 10
              figures in text. May 19, 1956.

           7. Mammals of Coahuila, Mexico. By Rollin H. Baker.
              Pp. 125-335, 75 figures in text. June 15, 1956.

           8. Comments on the taxonomic status of Apodemus
              peninsulae, with description of a new subspecies
              from North China. By J. Knox Jones, Jr. Pp. 337-346,
              1 figure in text, 1 table. August 15, 1956.

           9. Extensions of known ranges of Mexican bats. By
              Sydney Anderson. Pp. 347-351. August 15, 1956.

          10. A new bat (Genus Leptonycteris) from Coahuila. By
              Howard J. Stains. Pp. 353-356. January 21, 1957.

          11. A new species of pocket gopher (Genus Pappogeomys)
              from Jalisco, Mexico. By Robert J. Russell. Pp.
              357-361. January 21, 1957.

          12. Geographic variation in the pocket gopher, Thomomys
              bottae, in Colorado. By Phillip M. Youngman. Pp.
              363-387, 7 figures in text. February 21, 1958.

          13. New bog lemming (genus Synaptomys) from Nebraska.
              By J. Knox Jones, Jr. Pp. 385-388. May 12, 1958.

          14. Pleistocene bats from San Josecito Cave, Nuevo León,
              México. By J. Knox Jones, Jr. Pp. 389-396. December
              19, 1958.

          15. New subspecies of the rodent Baiomys from Central
              America. By Robert L. Packard. Pp. 397-404. December
              19, 1958.

          16. Mammals of the Grand Mesa, Colorado. By Sydney
              Anderson. Pp. 405-414, 1 figure in text, May 20,
              1959.

          17. Distribution, variation, and relationships of the
              montane vole, Microtus montanus. By Sydney Anderson.
              Pp. 415-511, 12 figures in text, 2 tables. August 1,
              1959.

          18. Conspecificity of two pocket mice, Perognathus
              goldmani and P. artus. By E. Raymond Hall and
              Marilyn Bailey Ogilvie. Pp. 513-518, 1 map. January
              14, 1960.

          19. Records of harvest mice, Reithrodontomys, from
              Central America, with description of a new subspecies
              from Nicaragua. By Sydney Anderson and J. Knox Jones,
              Jr. Pp. 519-529. January 14, 1960.

          20. Small carnivores from San Josecito Cave (Pleistocene),
              Nuevo León, México. By E. Raymond Hall. Pp. 531-538,
              1 figure in text. January 14, 1960.

          21. Pleistocene pocket gophers from San Josecito Cave,
              Nuevo León, México. By Robert J. Russell. Pp.
              539-548, 1 figure in text. January 14, 1960.

          22. Review of the insectivores of Korea. By J. Knox
              Jones, Jr., and David H. Johnson. Pp. 549-578.
              February 23, 1960.

          23. Speciation and evolution of the pygmy mice, genus
              Baiomys. By Robert L. Packard. Pp. 579-670, 4
              plates, 12 figures in text. June 16, 1960.

          Index. Pp. 671-690.

 Vol. 10.  1. Studies of birds killed in nocturnal migration. By
              Harrison B. Tordoff and Robert M. Mengel. Pp. 1-44,
              6 figures in text, 2 tables. September 12, 1956.

           2. Comparative breeding behavior of Ammospiza caudacuta
              and A. maritima. By Glen E. Woolfenden. Pp. 45-75,
              6 plates, 1 figure. December 20, 1956.

           3. The forest habitat of the University of Kansas
              Natural History Reservation. By Henry S. Fitch and
              Ronald R. McGregor. Pp. 77-127, 2 plates, 7 figures
              in text, 4 tables. December 31, 1956.

           4. Aspects of reproduction and development in the
              prairie vole (Microtus ochrogaster). By Henry S.
              Fitch. Pp. 129-161, 8 figures in text, 4 tables.
              December 19, 1957.

           5. Birds found on the Arctic slope of northern Alaska.
              By James W. Bee. Pp. 163-211, plates 9-10, 1 figure
              in text. March 12, 1958.

           6. The wood rats of Colorado: distribution and ecology.
              By Robert B. Finley, Jr. Pp. 213-552, 34 plates, 8
              figures in text, 35 tables. November 7, 1958.

           7. Home ranges and movements of the eastern cottontail
              in Kansas. By Donald W. Janes. Pp. 553-572, 4 plates,
              3 figures in text. May 4, 1959.

           8. Natural history of the salamander, Aneides hardyi.
              By Richard F. Johnston and Gerhard A. Schad. Pp.
              573-585. October 8, 1959.

           9. A new subspecies of lizard, Cnemidophorus sacki,
              from Michoacán, México. By William E. Duellman.
              Pp. 587-598, 2 figures in text. May 2, 1960.

          10. A taxonomic study of the middle American snake,
              Pituophis deppei. By William E. Duellman. Pp.
              599-610, 1 plate, 1 figure in text. May 2, 1960.

          Index. Pp. 611-626.

 Vol. 11.  1. The systematic status of the colubrid snake,
              Leptodeira discolor Günther. By William E. Duellman.
              Pp. 1-9, 4 figures. July 14, 1958.

           2. Natural history of the six-lined racerunner,
              Cnemidophorus sexlineatus. By Henry S. Fitch. Pp.
              11-62, 9 figures, 9 tables. September 19, 1958.

           3. Home ranges, territories, and seasonal movements of
              vertebrates of the Natural History Reservation. By
              Henry S. Fitch. Pp. 63-326, 6 plates, 24 figures in
              text, 3 tables. December 12, 1958.

           4. A new snake of the genus Geophis from Chihuahua,
              Mexico. By John M. Legler. Pp. 327-334, 2 figures
              in text. January 28, 1959.

           5. A new tortoise, genus Gopherus, from north-central
              Mexico. By John M. Legler. Pp. 335-343. April 24,
              1959.

           6. Fishes of Chautauqua, Cowley and Elk counties,
              Kansas. By Artie L. Metcalf. Pp. 345-400, 2 plates,
              2 figures in text, 10 tables. May 6, 1959.

           7. Fishes of the Big Blue river basin, Kansas. By W. L.
              Minckley. Pp. 401-442, 2 plates, 4 figures in text,
              5 tables. May 8, 1959.

           8. Birds from Coahuila, México. By Emil K. Urban. Pp.
              443-516. August 1, 1959.

           9. Description of a new softshell turtle from the
              southeastern United States. By Robert G. Webb.
              Pp. 517-525, 2 plates, 1 figure in text. August
              14, 1959.

          10. Natural history of the ornate box turtle, Terrapene
              ornata ornata Agassiz. By John M. Legler. Pp.
              527-669, 16 pls., 29 figures in text. March 7, 1960.

          Index Pp. 671-703.

 Vol. 12.  1. Functional morphology of three bats: Eumops, Myotis,
              Macrotus. By Terry A. Vaughan. Pp. 1-153, 4 plates,
              24 figures in text. July 8, 1959.

           2. The ancestry of modern Amphibia: a review of the
              evidence. By Theodore H. Eaton, Jr. Pp. 155-180, 10
              figures in text. July 10, 1959.

           3. The baculum in microtine rodents. By Sydney Anderson.
              Pp. 181-216, 49 figures in text. February 19, 1960.

           4. A new order of fishlike Amphibia from the Pennsylvanian
              of Kansas. By Theodore H. Eaton, Jr., and Peggy Lou
              Stewart. Pp. 217-240, 12 figures in text. May 2, 1960.

           5. Natural history of the bell vireo. By Jon C. Barlow.
              Pp. 241-296, 6 figures in text. March 7, 1962.

           6. Two new pelycosaurs from the lower Permian of
              Oklahoma. By Richard C. Fox. Pp. 297-307, 6 figures
              in text. May 21, 1962.

           7. Vertebrates from the barrier island of Tamaulipas,
              México. By Robert K. Selander, Richard F. Johnston,
              B. J. Wilks, and Gerald G. Raun. Pp. 309-345, pls.
              5-8. June 18, 1962.

              More numbers will appear in volume 12.

 Vol. 13.  1. Five natural hybrid combinations in minnows
              (Cyprinidae). By Frank B. Cross and W. L. Minckley.
              Pp. 1-18. June 1, 1960.

           2. A distributional study of the amphibians of the
              Isthmus of Tehuantepec, México. By William E.
              Duellman. Pp. 19-72, pls. 1-8, 3 figures in text.
              August 16, 1960.

           3. A new subspecies of the slider turtle (Pseudemys
              scripta) from Coahuila, México. By John M. Legler.
              Pp. 73-84, pls. 9-12, 3 figures in text. August 16,
              1960.

           4. Autecology of the copperhead. By Henry S. Fitch.
              Pp. 85-288, pls. 13-20, 26 figures in text. November
              30, 1960.

           5. Occurrence of the garter snake, Thamnophis sirtalis,
              in the Great Plains and Rocky Mountains. By Henry S.
              Fitch and T. Paul Maslin. Pp. 289-308, 4 figures in
              text. February 10, 1961.

           6. Fishes of the Wakarusa river in Kansas. By James E.
              Deacon and Artie L. Metcalf. Pp. 309-322, 1 figure
              in text. February 10, 1961.

           7. Geographic variation in the North American cyprinid
              fish, Hybopsis gracilis. By Leonard J. Olund and
              Frank B. Cross. Pp. 323-348, pls. 21-24, 2 figures
              in text. February 10, 1961.

           8. Descriptions of two species of frogs, genus
              Ptychohyla; studies of American hylid frogs, V. By
              William E. Duellman. Pp. 349-357, pl. 25, 2
              figures in text. April 27, 1961.

           9. Fish populations, following a drought, in the Neosho
              and Marais des Cygnes rivers of Kansas. By James
              Everett Deacon. Pp. 359-427, pls. 26-30, 3 figs.
              August 11, 1961.

          10. Recent soft-shelled turtles of North America (family
              Trionychidae). By Robert G. Webb. Pp. 429-611, pls.
              31-54, 24 figures in text. February 16, 1962.

          Index in press.

 Vol. 14.  1. Neotropical bats from western México. By Sydney
              Anderson. Pp. 1-8. October 24, 1960.

           2. Geographic variation in the harvest mouse,
              Reithrodontomys megalotis, on the central Great
              Plains and in adjacent regions. By J. Knox Jones,
              Jr., and B. Mursaloglu. Pp. 9-27, 1 figure in text.
              July 24, 1961.

           3. Mammals of Mesa Verde National Park, Colorado. By
              Sydney Anderson. Pp. 29-67, pls. 1 and 2, 3 figures
              in text. July 24, 1961.

           4. A new subspecies of the black myotis (bat) from
              eastern Mexico. By E. Raymond Hall and Ticul
              Alvarez. Pp. 69-72, 1 figure in text. December 29,
              1961.

           5. North American yellow bats, "Dasypterus," and a
              list of the named kinds of the genus Lasiurus Gray.
              By E. Raymond Hall and J. Knox Jones, Jr.
              Pp. 73-98, 4 figures in text. December 29, 1961.

           6. Natural history of the brush mouse (Peromyscus
              boylii) in Kansas with description of a new
              subspecies. By Charles A. Long. Pp. 99-111, 1 figure
              in text. December 29, 1961.

           7. Taxonomic status of some mice of the Peromyscus
              boylii group in eastern Mexico, with description of
              a new subspecies. By Ticul Alvarez. Pp. 113-120,
              1 figure in text. December 29, 1961.

           8. A new subspecies of ground squirrel (Spermophilus
              spilosoma) from Tamaulipas, Mexico. By Ticul
              Alvarez. Pp. 121-124. March 7, 1962.

           9. Taxonomic status of the free-tailed bat, Tadarida
              yucatanica Miller. By J. Knox Jones, Jr., and Ticul
              Alvarez. Pp. 125-133, 1 figure in text. March 7,
              1962.

          10. A new doglike carnivore, genus Cynarctus, from the
              Clarendonian Pliocene, of Texas. By E. Raymond Hall
              and Walter W. Dalquest. Pp. 135-138, 2 figures in
              text. April 30, 1962.

          11. A new subspecies of wood rat (Neotoma) from
              northeastern Mexico. By Ticul Alvarez. Pp. 139-143.
              April 30, 1962.

          12. Noteworthy mammals from Sinaloa, Mexico. By J. Knox
              Jones, Jr., Ticul Alvarez, and M. Raymond Lee. Pp.
              145-159, 1 figure in text. May 18, 1962.

          13. A new bat (Myotis) from Mexico. By E. Raymond Hall.
              Pp. 161-164, 1 figure in text. May 21, 1962.

              More numbers will appear in volume 14.

 Vol. 15.  1. The amphibians and reptiles of Michoacán, México.
              By William E. Duellman. Pp. 1-148, pls. 1-6, 11
              figures in text. December 20, 1961.

           2. Some reptiles and amphibians from Korea. By Robert
              G. Webb, J. Knox Jones, Jr., and George W. Byers.
              Pp. 149-173. January 31, 1962.

           3. A new species of frog (Genus Tomodactylus) from
              western México. By Robert G. Webb. Pp. 175-181,
              1 figure in text. March 7, 1962.

              More numbers will appear in volume 15.

       *       *       *       *       *


Transcriber's Notes


The University of Kansas Publications list was placed at the end of
this publication.

Original spelling and accent inconsistencies have been retained.

[M] represents the male symbol used in the original publication.

[F] represents the female symbol used in the original publication.

Italicized text is represented by _underscores_.

Bold text is represented by =equal signs=.










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