TEXAS MAMMALS

The importance of Texas in relation to geography and wildlife is no accident. Within the state is such a wide variation of soils, climate, and topography that the resultant vegetation and animal life are unusually rich. This diverse environment supports a resident fauna of 141 species of native terrestrial mammals, a number exceeded in the United States only by California and New Mexico. In addition to the native species that occur in the area naturally, there are also 12 exotics or nonnative species that have been introduced accidentally (house mouse, roof rat, Norway rat) or intentionally (nutria, red fox, feral pig, axis deer, fallow deer, sika deer, nilgai, barbary sheep, and blackbuck) by man and have become established as a part of the freeliving fauna. An asterisk (*) beside the common name in the species accounts indicates a nonnative species.

Terrestrial mammals in Texas belong to the orders Didelphimorphia (opossums), Insectivora (shrews and moles), Chiroptera (bats), Xenarthra (armadillos), Lagomorpha (hares and rabbits), Rodentia (rodents), Carnivora (carnivores), and Artiodactyla (even-toed ungulates). In addition, Texas is bounded by the waters of the Gulf of Mexico and 28 marine mammals of the orders Cetacea (whales and dolphins), Pinnipedia (seals), and Sirenia (manatees) enter the coastal waters of the state. The number of genera and species of Texas mammals in each of these groups is given in Table 1. This total of 181 mammals does not include several large, exotic ungulates that recently have been brought into the state and are kept for the most part under high fence and two domesticated species (dog and cat) which have taken up life in the wild state in many places and have significant impacts on other mammals living in those areas.

TABLE 1. The number of genera and species of mammals in Texas.

Texas is a keystone in understanding the distributional patterns of Recent mammals in the United States. Several species reach distributional limits within the state. The mammalian fauna includes many species that occur throughout the central United States, especially those associated with the central grasslands, others with the southeastern deciduous forests, many characteristic of the desert regions of the Mexican Plateau and the southwestern United States, and a few associated with the mountain regions of the western United States and the tropical regions of northeastern Mexico.

Other important features of the terrestrial mammalian fauna of Texas are the number of endemic species and the variability within species as reflected by the number of described subspecies. Five species are virtually confined in their distribution to Texas. There are 243 described taxa (species and subspecies) of native land mammals in the state, and 55 of the 141 species (39%) are represented by more than one subspecies.

Topics under this heading:

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