Wildlife Sciences

Range Reference Areas and The Condition of Shrubs on Mule Deer Winter Ranges

Charles E. Kay. 2009. Range Reference Areas and The Condition of Shrubs on Mule Deer Winter Ranges. Muley Crazy Magazine. Vol 8(1):35-40.

Dr. Charles E. Kay, Ph.D. Wildlife Ecology, Utah State University, is the author/editor of Wilderness and Political Ecology: Aboriginal Influences and the Original State of Nature [here], author of Are Lightning Fires Unnatural? A Comparison of Aboriginal and Lightning Ignition Rates in the United States [here], co-author of Native American influences on the development of forest ecosystems [here], and numerous other scientific papers.

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After predator control, range management is the key to maintaining healthy populations of mule deer and other wildlife. It is not just habitat, but the condition of that habitat. For instance, how do you tell if a range is being overgrazed? One way is to establish what are called range reference areas. There are a few places that have never been grazed by livestock, such as steep-sided mesa tops, where the vegetation can be compared with nearby grazed areas. Unfortunately, there are very few places in the West that have never been grazed by livestock and there are even fewer that deer and elk cannot reach. So in most areas it is necessary for managers to create their own range reference areas by building exclosures, which they have been doing for years.

If you are working in a national park or on a winter range where livestock use is prohibited, it is a relatively simple matter to build an 8-foot tall fence around a representative plant community, such as willows, aspen, grasslands, or upland shrubs. Then by measuring the vegetation inside and outside the exclosure on permanent sampling plots over time, you can determine what, if any, impacts wildlife are having on the range. It is also important to establish permanent photopoints when the exclosure is first erected.

If on the other hand, you are working on BLM or Forest Service lands that are grazed by livestock and wildlife, the design of the exclosure is a little more complicated. One part, termed the total-exclusion plot, is still high-game fenced to exclude both livestock and wildlife, while an adjacent area, called the livestock-exclusion plot, is fenced in such a manner that livestock are excluded but mule deer and/or elk can jump the low fence and graze/browse by themselves — please see the accompanying photo. Unfenced adjoining areas are grazed by both livestock and wildlife. Thus by measuring the vegetation in all three areas — total exclusion, livestock-exclusion wildlife-only use, and joint use — you can determine, what vegetation changes, if any, are being caused by wildlife separately from those caused by livestock. The total-exclusion portion of the exclosure can also be used to tell if climatic variation, disease, or insects are causing certain plants to decline.

As you might have guessed, the latter type of range reference area is called a three-part exclosure because vegetation conditions are measured under three different grazing treatments. During the 1950’s and 1960’s when mule deer populations were at all time highs, a series of three-part exclosures were built on BLM and Forest Service allotments throughout the West. Unfortunately the Federal land management agencies have no nation-wide program to maintain those exclosures and many have fallen into disrepair, which is extremely shortsighted. Because without long-term range reference areas there is no way to determine what is happening on our public lands.

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The Return of Caribou to Ungava

A.T. Bergerud, Stuart N. Luttich, and Lodewiih Camps. 2007. The Return of Caribou to Ungava.
McGill-Queen’s University Press, Montreal, QU.

Review by Charles E. Kay, Utah State University, from the Canadian Field-Naturalist, Vol. 121, No. 2, April-June 2007

This is the most comprehensive book on caribou ecology and predator-prey relationships that has appeared in many years, perhaps ever. Not only is the research seminal, but the authors systematically dismantle paradigms that have been in vogue for years. According to the authors, caribou biologists have wasted the last 50 years measuring lichens on winter ranges, when they should have been documenting plant production on summer ranges. Wolves, along with human hunters, both limit and regulate caribou populations, not habitat. Food on the summer range only regulates at high densities and only after the range has been overgrazed. Wolves are driving Woodland and Mountain Caribou to extinction. Caribou populations where Wolves are absent maintain densities 100 times greater than predated herds. The reason arctic Caribou migrate to barren ground calving areas is to avoid Wolves tied to den sites at treeline. Even so, if it were not for periodic rabies epidemics, migratory caribou populations would be severely limited by wolf predation. Volcanic eruptions half a world away trigger population declines in arctic Caribou at high densities. And this is just for starters.

The book chronicles the history of the George River Caribou in Labrador and Quebec from near extinction during the early 1900’s to an estimated 600,000 animals before the herd declined. The authors explore the various hypotheses that have been proposed to explain these fluctuations, and present dataset after dataset to separate between competing explanations. In addition, the authors discuss virtually every other caribou population that has been studied in North America, Scandinavia, and beyond, including the difference between migratory and sedentary herds, which is key to understanding this species’ ecology.

To the south of Ungava are small non-migratory populations of Woodland Caribou that are being driven to extinction by wolf predation. But in reality, Moose and Whitetails are to blame. Historically, these areas sustained low-density, widely-spaced Caribou that in and of themselves could support few or no Wolves. Moose and Whitetails were absent. But since the early 1900’s, Moose and Whitetails have extended their range providing alternative prey for Wolves, where none existed before. The Wolves then drive the more vulnerable Caribou ever downward. That is to say, the addition of alternative prey did not buffer predation on Caribou, but instead increased predation pressure contrary to what many people would expect. But that is not the most intriguing part.

Why were Moose and Whitetails absent historically and prehistorically? The authors contend that logging changed coniferous forests to secondary deciduous species favored by Moose and Whitetails. In this I believe they erred because fire history data indicate there was always a strong deciduous component in those forests. Besides, Moose and Whitetails can survive on a winter diet of Balsam Fir, as they do on Isle Royale and Anticosti Island. Instead, I believe that native hunters once kept eastern moose populations in check, as I know native hunters did in western North America where there are more Moose today than at any time in the last 12,000 years - - see Alces 33:141-164. Historically and prehistorically, native hunters extirpated Moose over large areas because, like the Wolves discussed above, humans had a multitude of alternative prey including vegetal resources and fish unavailable to carnivores. As aboriginal hunting pressure declines prey populations increase. In fact, the authors note that the influenza epidemic of 1918 decimated native populations on Ungava, which in turn allowed Caribou to increase.

I certainly commend the authors for presenting data on aboriginal peoples since the time Ungava was first inhabited and for describing how human hunting impacts Caribou. Most other studies of ungulate ecology begin with the premise that native people are irrelevant because everything was a “wilderness” untouched by the hand of man prior to the arrival of Europeans; e.g., see The Kruger Experience. As I have explained elsewhere, however, this is a fatal error. The authors did not make that mistake but I would suggest they need to look deeper into human evolutionary ecology. Take the seemingly random movements of Caribou, a subject covered at length in this book.

Unfortunately, the authors neglected to consult Binford’s data on Inuit caribou hunters - - see Numamint Ethnoarchaeology. One of the questions Binford asked was how do caribou hunters select a direction to hunt when they have no prior knowledge of where the Caribou are? The Inuit base their decisions on what we in the West would call mysticism. By careful observation, however, Binford determined that Inuit pre-hunt behavior was simply a random number generator. That is to say, in these cases, the Inuit hunted randomly, which makes perfect ecological sense, odd though it may seem.

If the Caribou moved in a predictable pattern, they would be easy prey for aboriginal hunters, as the authors note when the Ungava herd is forced by topography to cross the George River at Indian House Lake. If the hunters hunted in a predictable pattern, the Caribou would quickly learn to avoid the hunters, and the people would starve. The solution to the Caribou’s problem is to move as randomly as possible, while the solution to the hunter’s predicament is to hunt randomly. This co-evolution occurred over thousands of years and probably is the only evolutionary stable strategy available to both Caribou and humans and then only because the caribou’s range was vast and diverse. The authors note that even when Ungava Caribou numbered only 15,000 animals, spread over an immense area, aboriginal hunting alone kept the herd from increasing. Using dog sleds, native hunters would follow caribou tracks for days, until the animals were killed or the trail lost.

The Return of Caribou to Ungava should be read by everyone with even a passing interest in northern ecology, caribou management, or predator-prey relationships. It should also be read by historians, anthropologists, and archaeologists.