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The Mammals of Texas - Online Edition

GEOGRAPHIC DISTRIBUTION OF LAND MAMMALS

Texas may be conveniently arranged into four regions based on the ecological distribution of mammals. These are the Trans-Pecos, Plains Country, East Texas, and the Rio Grande Plains (Figure 4). The Trans-Pecos region includes the mountain and basin country west of the Pecos River. The Plains Country includes the High Plains, Rolling Plains, Cross Timbers area, and the Edwards Plateau. Included within the East Texas region are the Pineywoods, central Texas Woodlands, Blackland Prairies, and Coastal Prairies and Marshes. The Rio Grande Plains encompasses the South Texas brushlands. The Balcones Escarpment serves as the major physiographic barrier separating the Plains Country from East Texas and the Rio Grande Plains. The boundary between East Texas and the Rio Grande Plains is positioned between the Guadalupe and San Antonio rivers where pedocal and pedalfer soils meet.

The distributional patterns of land mammals in Texas conform to five major patterns. These are: (1) ubiquitous species that range throughout most, or all, of the state (included in this group are several species that are now extinct or whose distributions have shrunk markedly in the past 150 years); (2) species that are distributed primarily in one of the four divisions of the state; (3) western species distributed in the Trans-Pecos and Plains Country; (4) western species distributed in the Trans-Pecos and Plains Country, but which also occur on the South Texas Plains; and (5) eastern species distributed principally east of the 100th meridian. Mammals assigned to each of these categories are listed. It should be noted that certain species occur slightly outside of the boundaries of the category to which they have been assigned.

The greatest number of unique elements in the mammal fauna of Texas occur in the Trans-Pecos region. Almost one-third of the 92 species of mammals that occur in the Trans-Pecos are primarily restricted in distribution to that region. Most of these mammals are species characteristic of the arid Mexican Plateau and southwestern United States or the montane woodlands of the western United States. The fewest number of unique elements is found in the Plains Country. The 15 mammals unique to East Texas are species characteristic of the deciduous forests and coastal prairies of the southeastern United States, which reach their western distributional limits in Texas. The Rio Grande Plain supports 11 unique elements, most of which are characteristic of the tropical lowlands of northeastern Mexico and reach their northern distributional limits in south Texas.

MAMMALS GENERALLY DISTRIBUTED THROUGHOUT THE STATE:

Virginia Opossum Didelphis virginiana (absent from portions of the Trans-Pecos)
Silver-haired Bat Lasionycteris noctivagans
Big Brown Bat Eptesicus fuscus (not in Rio Grande Plains)
Eastern Red Bat Lasiurus borealis
Hoary Bat Lasiurus cinereus
Brazilian Free-tailed Bat Tadarida brasiliensis
Eastern Cottontail Sylvilagus floridanus
Black-tailed Jackrabbit Lepus californicus (not in the Big Thicket of East Texas)
Hispid Pocket Mouse Chaetodipus hispidus (not in the Big Thicket of East Texas)
American Beaver Castor canadensis
Fulvous Harvest Mouse Reithrodontomys fulvescens (not on the High Plains)
White-footed Mouse Peromyscus leucopus
Deer Mouse Peromyscus maniculatus
Hispid Cotton Rat Sigmodon hispidus
Coyote Canis latrans
Common Gray Fox Urocyon cinereoargenteus
Black Bear Ursus americanus (now extinct except for remnant populations in the Trans-Pecos)
Ringtail Bassariscus astutus
Common Raccoon Procyon lotor
Long-tailed Weasel Mustela frenata
Striped Skunk Mephitis mephitis
Mountain Lion Felis concolor (now gone from much of the range except South Texas and the Trans-Pecos)
Bobcat Lynx rufus
White-tailed Deer Odocoileus virginianus
Bison Bos bison (now extinct in the wild in Texas)

 

MAMMALS OCCURRING PRINCIPALLY IN THE TRANS-PECOS:

Mexican Long-nosed Bat Leptonycteris nivalis
California Myotis Myotis californicus (disjunct record from Rolling Plains)
Fringed Myotis Myotis thysanodes (disjunct record from Rolling Plains)
Long-legged Myotis Myotis volans (disjunct record from Rolling Plains)
Yuma Myotis Myotis yumanensis
Western Red Bat Lasiurus blossevillii
Spotted Bat Euderma maculatum
Pocketed Free-tailed Bat Nyctinomops femorosacca
Western Mastiff Bat Eumops perotis
Gray-footed Chipmunk Tamias canipes
Texas Antelope Squirrel Ammospermophilus interpres (also in western part of Edwards Plateau)
Desert Pocket Gopher Geomys arenarius
Rock Pocket Mouse Chaetodipus intermedius
Nelson’s Pocket Mouse Chaetodipus nelsoni
Desert Pocket Mouse Chaetodipus penicillatus
Merriam’s Kangaroo Rat Dipodomys merriami
Banner-tailed Kangaroo Rat Dipodomys spectabilis (also in southern part of High Plains)
Brush Mouse Peromyscus boylii (also on Escarpment breaks of Rolling Plains)
Northern Rock Mouse Peromyscus nasutus
Cactus Mouse Peromyscus eremicus (also in extreme western part of Rio Grande Plain)
Mearns’ Grasshopper Mouse Onychomys arenicola
Tawny-bellied Cotton Rat Sigmodon fulviventer
Yellow-nosed Cotton Rat Sigmodon ochrognathus
Mexican Woodrat Neotoma mexicana
Mexican Vole Microtus mexicanus
Hooded Skunk Mephitis macroura
Wapiti or Elk Cervus elaphus (native population extinct; reintroduced into Guadalupe Mountains)
Mountain Sheep Ovis canadensis (native population extinct; reintroduced into several mountain ranges)

MAMMALS OCCURRING PRINCIPALLY IN THE PLAINS COUNTRY:

Thirteen-lined Ground Squirrel Spermophilus tridecemlineatus (also in a narrow strip through Central Texas from the Red River and Dallas region south to Corpus Christi and east to Colorado County)
Plains Pocket Gopher Geomys bursarius
Jones’ Pocket Gopher Geomys knoxjonesi
Llano Pocket Gopher Geomys texensis
Plains Pocket Mouse Perognathus flavescens (also in El Paso County)
Texas Kangaroo Rat Dipodomys elator
Texas Mouse Peromyscus attwateri
Prairie Vole Microtus ochrogaster (subspecies haydeni)
Black-footed Ferret Mustela nigripes (now extinct in Texas)

 

MAMMALS OCCURRING PRINCIPALLY IN THE RIO GRANDE PLAINS:

Mexican Long-tongued Bat Choeronycteris mexicana
Southern Yellow Bat Lasiurus ega
Texas Pocket Gopher Geomys personatus
Gulf Coast Kangaroo Rat Dipodomys compactus
Mexican Spiny Pocket Mouse Liomys irroratus
Coues’ Rice Rat Oryzomys couesi
White-nosed Coati Nasua narica (also in Big Bend region of the Trans-Pecos)
Eastern Hog-nosed Skunk Conepatus leuconotus
Ocelot Felis pardalis (formerly more widely distributed)
Margay Felis wiedii (now extinct in Texas)
Jaguarundi Felis yagouaroundi

MAMMALS OCCURRING PRINCIPALLY IN EAST TEXAS:

Southern Short-tailed Shrew Blarina carolinensis
Southeastern Myotis Myotis austroriparius
Seminole Bat Lasiurus seminolus
Rafinesque’s Big-eared Bat Plecotus rafinesquii
Swamp Rabbit Sylvilagus aquaticus
Eastern Gray Squirrel Sciurus carolinensis
Eastern Flying Squirrel Glaucomys volans (barely enters the Cross Timbers area of the Plains Country)
Attwater’s Pocket Gopher Geomys attwateri
Baird’s Pocket Gopher Geomys breviceps
Marsh Rice Rat Oryzomys palustris (also in coastal region of Rio Grande Plain)
Eastern Harvest Mouse Reithrodontomys humulis
Cotton Mouse Peromyscus gossypinus
Golden Mouse Ochrotomys nuttalli
Prairie Vole Microtus ochrogaster (subspecies ludovicianus)
River Otter Lutra canadensis

 

MAMMALS OCCURRING PRINCIPALLY IN WEST TEXAS
(PLAINS REGION AND TRANS-PECOS):

Western Small-footed Myotis Myotis ciliolabrum
Western Pipistrelle Pipistrellus hesperus
Townsend’s Big-eared Bat Plecotus townsendii
Rock Squirrel Spermophilus variegatus
Black-tailed Prairie Dog Cynomys ludovicianus
Botta’s Pocket Gopher Thomomys bottae
Yellow-faced Pocket Gopher Cratogeomys castanops
Plains Harvest Mouse Reithrodontomys montanus (also in the Blackland Prairies of East Texas)
Silky Pocket Mouse Perognathus flavus
Western Harvest Mouse Reithrodontomys megalotis
White-ankled Mouse Peromyscus pectoralis
Piņon Mouse Peromyscus truei
White-throated Woodrat Neotoma albigula
Porcupine Erethizon dorsatum
Swift or Kit Fox Vulpes velox
Grizzly or Brown Bear Ursus arctos (now extinct)
Mule Deer Odocoileus hemionus

MAMMALS OCCURRING PRINCIPALLY IN WESTERN TEXAS
(TRANS-PECOS AND PLAINS REGION) AND RIO GRANDE PLAINS:

Desert Shrew Notiosorex crawfordi
Ghost-faced Bat Mormoops megalophylla
Cave Myotis Myotis velifer
Pallid Bat Antrozous pallidus
Big Free-tailed Bat Nyctinomops macrotis (two records from East Texas)
Desert Cottontail Sylvilagus audubonii
Mexican Ground Squirrel Spermophilus mexicanus
Spotted Ground Squirrel Spermophilus spilosoma
Merriam’s Pocket Mouse Perognathus merriami
Ord’s Kangaroo Rat Dipodomys ordii
Northern Grasshopper Mouse Onychomys leucogaster
Southern Plains Woodrat Neotoma micropus
Gray Wolf Canis lupus (now extinct in Texas)
American Badger Taxidea taxus
Western Spotted Skunk Spilogale gracilis
Common Hog-nosed Skunk Conepatus mesoleucus (relict population in the Big Thicket probably extinct)
Collared Peccary Tayassu tajacu
Pronghorn Antilocapra americana (now extinct in Rio Grande Plains)

MAMMALS OCCURRING PRINCIPALLY EAST OF THE 100TH MERIDIAN:

Elliot’s Short-tailed Shrew Blarina hylophaga
Least Shrew Cryptotis parva
Eastern Mole Scalopus aquaticus
Eastern Pipistrelle Pipistrellus subflavus
Northern Yellow Bat Lasiurus intermedius
Evening Bat Nycticeius humeralis
Nine-banded Armadillo Dasypus novemcinctus
Eastern Fox Squirrel Sciurus niger
Northern Pygmy Mouse Baiomys taylori (has spread to Plains regions)
Eastern Woodrat Neotoma floridana
Woodland Vole Microtus pinetorum
Common Muskrat Ondatra zibethicus (also in Canadian, Pecos, and Rio Grande drainages)
Red Wolf Canis rufus (now extinct in Texas)
Mink Mustela vison
Eastern Spotted Skunk Spilogale putorius
Jaguar Panthera onca (now extinct in Texas)

 

Five species of mammals (all rodents) are unique to Texas in the sense that most, or all, of their known geographic range is confined to the mainland part of the state. These are:

Dipodomys elator — known from a few counties in the mesquite plains of north-central Texas and one county in Oklahoma;

Dipodomys compactus — known from the barrier islands of Texas and Tamaulipas, Mexico, and the South Texas Plains;

Geomys attwateri — known from East Texas (between the Brazos and San Antonio rivers);

Geomys personatus — known from the barrier islands of Texas and Tamaulipas, Mexico, and the South Texas Plains; and

Geomys texensis — known from eight counties in the Texas Hill Country.

There are three species of mammals (Diphylla ecaudata, Myotis lucifugus, Myotis septentrionalis) whose occurrence in Texas may be regarded as accidental. Resident breeding populations of these species probably never existed within the state. The Texas records for all three are far outside of their main range and only a single record exists for each in the state. Furthermore, all three are bats which are well known for their wandering movements.

Other topics under Texas Mammals:

Diversity of Land Mammals
Critical Species
Conservation Strategies
Key to the Major Groups (Orders) of Mammals in Texas