CARNIVORES IN ECOSYSTEMS.
This book, written by 25 university and agency researchers, describes the science and conservation of carnivores in the Greater Yellowstone Ecosystem (GYE). The emphasis, however, is on a few large charismatic carnivores in Yellowstone National Park (YNP) which lies at the center of the ecosystem. The editors' purpose is "to begin integration and synthesis of the remarkable scientific legacy that exists for the GYE's carnivores and to evaluate how we can best position ourselves to meet the growing conservation challenge in this and other ecosystems around the world."
Within YNP there is complete protection of carnivores, but that has not always been the case. As described in this book, changes in the park administration's attitude toward and treatment of its wildlife has changed dramatically across the years, reflecting changes in society's attitudes and values. Readers of this book should keep in mind that much of the GYE (nearly 8 million hectares) is comprised of USDA Forest Service lands and private lands where the non-endangered carnivores are subject to harvest and where livestock on private and federal lands tempt the fate of bears and wolves.
Since gray wolves were restored by reintroduction in 1995 and 1996, the area has supported the complete suite of carnivores present before Euro-American exploration. Those species include: grizzly bear, black bear, coyote, red fox, cougar, lynx, bobcat, marten, mink, short-tailed and long-tailed weasels, raccoon, badger, river otter, and striped skunk. Most are difficult and expensive to study. Whereas the largest are fairly well researched, knowledge of the fisher, wolverine, river otter, mink, lynx, bobcat, and raccoon is almost entirely from anecdote. Thus, the book's discussions of those species draw heavily on information obtained in other areas.
The book consists of 12 chapters. Bears, wolves, cougars, and coyotes are the primary subject of "case history" chapters. The mesocarnivore community (11 species) is described in a single chapter, reflecting the dearth of information mentioned above. Other chapters deal with issues such as the evolution of human attitudes about carnivores and Yellowstone Park and with contentious conservation and management issues there. Examples include the management of black bears and grizzly bears relative to park garbage dumps, alleged damage to vegetation by overpopulated ungulates, results of the 1988 fires, and the "natural regulation" ungulate management policy of the Park Service. We read that YNP is important for carnivore research because the carnivore guild can be studied in a nearly unexploited situation for comparison with other areas. For example, coyotes can be studied in the absence of exploitation by humans which occurs almost everywhere else. Authors of different chapters disagree about whether large carn ivores generally can serve as "umbrella" species for all carnivores. Buskirk in Chapter 7 insists they cannot because of the importance of habitat structure to smaller carnivores (e.g., martens).
If I had to select any one chapter for managers and decision-makers to read, it probably would be Chapter 11. That chapter addresses the relation between genetics, population size, dispersal pattern, and extinction probability of GYE carnivores, and it makes a strong impression. The alarming rate at which private land is being developed around the periphery of the GYE is increasingly isolating it from wilderness areas to the north and west. For most carnivores, little if any, gene flow is occurring between this and any other population. While that may not be a problem for some carnivores, it may not bode well for species such the grizzly bear which has an effective population size of only 13-65.
Appropriately, the book includes coverage of the prey available to carnivores, from elk and bison to small mammals. Excellent long term data on ungulates and range condition are available. A chapter on "Coyotes and canid coexistence in Yellowstone" contains the best discussion of coyote social organization I have seen. Also, it addresses competition and coexistence of wolves, coyotes, and red foxes in YNP. Much will be learned about that subject in the next few years. Already, wolves have taken a heavy toll on coyotes.
The addition of wolves to the carnivore guild has instilled excitement and a new sense of urgency in researchers. The topic of wolf restoration shows up in nearly every chapter; significant impacts to ecosystem structure and function are expected. Indeed, the pre-existence of information on other carnivores, the prey species, the vegetation, and the climate, creates a rare opportunity to learn if and how a major predator will create ripple effects through the system. However, too much space is devoted to predicting (by modeling and otherwise) the impacts wolves may have. Wolves have been in the system for over five years and the time has come to discontinue the reporting of predictions that served to help justify their reintroduction and begin the reporting of new findings. Hopefully the addition of wolves will lead to better understanding of the natural dynamics of the system, including the "top down" versus "bottom up" regulation debate and the matter of compensatory mortality of elk about which so much ha s been written. Several years of data will be needed.
The most arduous reading in the book is the final chapter which offers an overview of the state of carnivore science. The limited contribution of carnivore science to ecological theory and synthesis is discussed in light of inherent difficulties and expense of studying carnivores and the limited opportunities for experimentation and hypothesis testing. Researchers are mildly chastised for not taking advantage of alternative approaches to research. There is an insightful discussion of the utility of the concepts of keystone and umbrella species. Considerable space is devoted to advocating use of behavioral phenotypes for building more realistic landscape models. The attempt to cover too much ground, in combination with a writing style that is less than user-friendly, will result in few readers making it through this chapter.
The appearance of this book will not enhance your coffee table or desk top. Figures are in black and white, and it is unfortunate that several of the book's lower profile subjects did not even warrant a photograph. The strength is in the text and the impressive quantity of information that has been brought together in one volume. Except as noted above, the writing is clear. The most valuable use of the book will be as a reference text. Extensive lists of references after each chapter will be valuable to many readers. (The last chapter lists 727!) There is some redundancy between chapters, and a few errors are noticeable.
Anyone with more than a casual interest in carnivores and/or the GYE will find this hook worth reading. I believe readers will come away with a fuller understanding of carnivores in the region, and how they relate to one another, their prey, the landscape, and to humans. Whether this hook will be read by decision makers who are in the best position to make a difference for this ecosystem, I cannot predict.