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Wyoming author describes state mammal species in recently published book

by Wyoming Livestock Roundup

Steven Buskirk, author of Wild Mammals of Wyoming and Yellowstone National Park, was a professor at the University of Wyoming for 30 years.

“I taught mammalogy for 27 years, so I was involved in mammal biology for a long time. All of my research had to do with mammals and mammal ecology,” he explains.

Buskirk’s book was published in January, and the introductory pages state, “This book is a review and compilation of the identification, taxonomy, zoogeography, ecology and conservation of wild mammals native to Wyoming.”

The book includes a number of introductory chapters to set the stage, including a history of mammalogy in Wyoming and the mammals that were present in the region before humans arrived and before European settlers arrived in the area.

How vegetation relates to wildlife habitat is also covered, and the narrative addresses conservation and management throughout the state as well, including efforts related to Yellowstone National Park.

Mammal species

“Then the book goes into species accounts. Each of them has a section on the description of the animal, its dimensions and what it looks like and if it has a legal status such as big game animal, furbearer or predator. There is also a big emphasis on distribution and habitat associations,” Buskirk describes.

Population ecology and behavioral ecology of each species are also discussed, addressing how Wyoming mammals impact the environment around them.

Buskirk notes, “For each species, I try to provide ecological accounts on the effects of the species. Do they disperse seed? Are they important herbivores? Are they effective predators? Do they participate in food webs? Then, in the conservation and management section, I mention their economic importance, either positive or negative, and refer to species that have been controlled locally or over wider areas.”

Familiar animals

Farmers and ranchers will be familiar with many of the species mentioned in the book from living on the land and encountering various species.

“They probably consider some of these species desirable – or at least not a problem to have around – and then there are other species that are considered to be agricultural pests. Those are described or mentioned where they come up, including prairie dogs and ground squirrels,” he notes.

Buskirk also comments that species such as skunks and coyotes may only be problematic some of the time or when their populations become too large.

Red fox

“One of the really interesting species is the red fox. Red foxes are generally tolerated pretty well by ranchers, and they aren’t as aggressively controlled as coyotes,” he remarks.

Red foxes are typically found near towns, on the edges of cities and associated with farms, ranches or other developments. In Wyoming, the species generally prefers to be somewhat near people and when populations are high, they are even spotted in parks, alleyways and streets.

“Red foxes are an example of a species that is somewhat dependent on humans because humans control the coyotes,” he says. “If they live close enough to human structures and human enterprises, foxes can steal dog food, get some snacks here and there, get into the trash and, at the same time, live in a coyote-free world. That’s a good situation for a red fox.”

Expanding northward

Other similar anecdotes can be found throughout the book, including changes in distribution for species such as the black-tailed jackrabbit and the Virginia opossum.

Black-tailed jackrabbit populations are expanding northward at a rate of approximately four or five miles per year, and Virginia opossums are expanding upstream along the North Platte at a rate of about one to two miles per year.

“There are other mammals expanding their geographic range northward, and this is presumably because of the warming climate. We know the climate is warming, and some of these animals are sensitive to temperature. Given the warmer climate, they move north,” he adds.

In 1980, the pygmy rabbit was discovered in Wyoming, and subsequent survey efforts revealed populations scattered throughout the southwestern part of the state, especially in old, large stands of big sagebrush.

“Pygmy rabbits might look like they’ve expanded in range quickly, but really, they are a case of a species that we learned how to search for. We discovered, over the last 40 years, they were much more widely distributed than was first realized,” he explains.

Available data

In some cases, there is limited information available to describe species. Shrews, for example, have been detected in Wyoming, but very little is known about them. Species like elk on the other hand have been studied extensively and information is widely available.

“One of the challenges was trying to treat each species equally. In other words, we wanted to give as much weight to a shrew that is very obscure and not very well understood as to the mule deer, about which we know a great deal,” he comments.

Buskirk’s book took nearly 5.5 years to complete. It is intended for both lay people and academics, and the author made efforts to use language that provides accessible information for both audiences.

“It includes about 1,000 footnotes, and it has about 1,200 references, so anybody who wants to get into the literature in more detail can find the starting points for that literature in the book,” he says.

Time for an update

The first comprehensive book about Wyoming mammals was published in 1965, followed by another book in 1987. The first one was mostly a catalogue of state mammals, and the second book built upon the 1965 publication, adding ecological information related to different species.

There are over 117 mammalian species in the state that are native or naturalized non-natives of North American origin.

“It’s been 30 years since there was a new book, and it was time to update mammals that are in Wyoming, the new information that we know about them and to provide new information about who identified them, their ecology, their conservation and management. This book does all of that,” notes Buskirk.

Natasha Wheeler is editor of the Wyoming Livestock Roundup and can be contacted at

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