Preface

This book represents the seventh account detailing the species of mammals that occur in Texas with information about their lives and economic importance. The Texas Parks and Wildlife Department (TPWD) and its predecessor, the Texas Game and Fish Commission, published the first five editions. Dr. Walter P. Taylor and Dr. William B. Davis collaborated in 1947 to prepare The Mammals of Texas as Bulletin No. 27 of the former Texas Game and Fish Commission. Recognizing the growing interest in Texas mammals and the expanding knowledge about the many kinds of mammals in the state, Dr. Davis in 1960 wrote an entirely new bulletin, designated as Bulletin No. 41 of the TPWD, which served as an identification key to Texas mammals and also provided information on their distribution and life histories. Dr. Davis revised Bulletin No. 41 in 1966 and again in 1974. The fifth edition of The Mammals of Texas was published in 1994, with Dr. David J. Schmidly (DJS) as coauthor, and was distributed by the University of Texas Press. Dr. Davis died in 1995, and, by prior agreement with him, the 2004 version was authored solely by DJS. In this, the newest edition, DJS is joined by coauthor Dr. Robert D. Bradley (RDB), mammalogist and Professor of Biology at Texas Tech University.

Since the 2004 version, three contributing factors have provided the impetus for a seventh edition. First, the influx of molecular systematic data has impacted the taxonomy of several Texas mammals (more on this later). Second, continued efforts by field biologists have provided many new distributional records. Third, copies of the sixth version of The Mammals of Texas have become scarce. The TPWD, in cooperation with the University of Texas Press, has kindly agreed to publish this latest revision.

This new edition incorporates updated and needed revisions in the species distribution maps, taxonomic names, and other portions of the book. Many of the changes were made to update the extensive taxonomic revisions that have been adopted since the last edition as well as the identification keys and geographic ranges of mammals in Texas and its adjacent waters. The natural history descriptions include some of the same information detailed by DJS in the 2004 edition as well as pertinent new material. These updates have been taken from observations recorded by other researchers and reported in the scientific literature as well as the personal experiences of DJS and RDB based on nearly 75 years of collective experience studying mammals in Texas.

This edition continues to include subspecies of mammals in the state, reflecting the most updated taxonomy for each species. Subspecies are geographically defined aggregates of local populations that differ taxonomically (usually morphologically) from other such subdivisions of the species. Where the boundaries of subspecies abut, they interbreed with one another, creating zones of intergradation, whereas different species in areas of abutment or overlap are reproductively isolated and maintain their distinctness. The subspecies designations have been adapted from "Annotated Checklist of Recent Land Mammals of Texas, 2008" by Richard Manning, Clyde Jones, and Frank Yancey (Occasional Papers 278, Museum of Texas Tech University, 2008).

For the first time in the history of this volume, subspecies have been depicted on the distribution maps. Detailed studies of geographic variation are now available for nearly all Texas mammals. For some species we have incorporated distributions from these recent studies; for others we have followed subspecies boundaries as depicted by E. Raymond Hall, who in 1981 wrote a two-volume treatise on North American mammals.

The conservation status of each species has been updated to include the latest assessment for mammals by the International Union for the Conservation of Nature (IUCN), as well as information provided in three recent books about Texas mammals: DJS's book, Texas Natural History: A Century of Change, for land mammals; The Marine Mammals of the Gulf of Mexico, by Bernd Würsig, Thomas Jefferson, and DJS, for marine mammals; and Bats of Texas, by Loren Ammerman, Christine Hice, and DJS, for volant mammals in the state (the latter is a revision of DJS's 1992 Bats of Texas). Other useful references about the conservation status of Texas's mammal fauna have been included in appendix 3.

Species considered to be in trouble are those with legal status as endangered or threatened as determined by the US Fish and Wildlife Service and the TPWD, and this information been updated in this edition. Many rare species have highly localized distributions and others are only migrants in the state. Others were formerly widely distributed and in recent decades have suffered from a variety of circumstances that caused local extinctions in substantial parts of their range in the state. Several native carnivores in Texas are now extinct, primarily as a result of overharvesting and predator control efforts in the latter part of the nineteenth and early part of the twentieth centuries.

A new feature has been incorporated into this edition of the book. Each species account now includes a new section that summarizes the population status of that particular mammal in the state according to the following categories:

Common: A common species is one that is abundant wherever it occurs in the state. Most common species are widely distributed over a geographic area and are represented by viable, sustainable populations. These are species that are regularly observed or captured by collectors.

Uncommon: An uncommon species may or may not be widely distributed but does not occur in large numbers. These are species that typically occur in such low numbers that they are only occasionally observed and sporadically captured. Uncommon species are not necessarily rare or endangered.

Rare: A rare species is one that is present in such small numbers throughout the state that it is seldom seen or encountered. Although not threatened with extinction, a rare species may become endangered if conditions in its environment change. Species in this group often appear on official endangered, threatened, or declining species lists.

Extinct: An extinct species is one that once occurred but now no longer exists in the state.

Extralimital: An extralimital species is known on the basis of only one or a few records in the state that probably resulted from unusual wanderings of animals into the region from other areas. There is no indication these species have viable, reproducing populations in the state.

Introduced: An introduced species is one that does not occur naturally in the state but has been established with human assistance in such numbers that they exist as wild populations over a regional part of the state.

Feral: A feral species is one that was domesticated by humans for agriculture purposes and subsequently became established in the wild where it now lives without animal husbandry assistance.

Enigmatic: An enigmatic species is one whose occurrence is sporadic and difficult to explain with any degree of biological certainty.

Another addition to this new edition is a separate chapter about domesticated mammals, many of which live in the wild or feral state and thus co-exist with our native species.

Simplicity has always been the basic goal in the organization of this book and remains so in this new edition. Accounts for each species are arranged so that they contain in sequence: (1) a brief description of the mammal, with special emphasis given to distinguishing features, accompanied in most cases by a photograph; (2) a description of the geographic distribution of the species in Texas, with reference to a map (except for cetaceans, feral and domesticated animals, and some introduced species); (3) a list of the subspecies recognized for each species (not provided for most of the introduced, nonnative species); (4) a discussion of some of the basic life history of the mammal, including habitat preferences, reproduction, behavior, and food habits; (5) an assessment of the population status (as outlined above) of each species; (6) a brief discussion of the conservation status of the species in Texas; and (7) a remarks section for ancillary information.

Those readers interested in more detail about the natural history of Texas mammals are referred to the Mammalian Species series, published by the American Society of Mammalogists. The series provides detailed references and information for individual species of mammals. To date, Mammalian Species accounts are available for 154 species of Texas mammals. Appendix 5 provides a list of the accounts available for Texas mammals. Mammalian Species may be found in many university libraries or can be ordered from the website at http://www.science.smith.edu/departments/Biology/VHAYSSEN
/msi/. Many of the accounts can be downloaded free from that site. In addition, the website of the American Society of Mammalogists, www.mammal
society.org, is an excellent resource for information about mammals and the science of mammalogy.

Finally, we updated and expanded the appendices (1–7) and glossary, and added an index to scientific and common names. These sections are intended to continue to provide the reader with helpful materials concerning specimen collection, note taking, references, and scientific vocabulary.

 

From The Mammals of Texas, Seventh Edition by David J. Schmidly and Robert D. Bradley, copyright © 1994, 2004, 2016.  Courtesy of the University of Texas Press.