Thursday, January 19, 2012


Read an excerpt.


472 pages | 32 color plates, 13 halftones, 63 line drawings, 73 tables | 8-1/2 x 11 | © 2003

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Wolves are some of the world's most charismatic and controversial animals, capturing the imaginations of their friends and foes alike. Highly intelligent and adaptable, they hunt and play together in close-knit packs, sometimes roaming over hundreds of square miles in search of food. Once teetering on the brink of extinction across much of the United States and Europe, wolves have made a tremendous comeback in recent years, thanks to legal protection, changing human attitudes, and efforts to reintroduce them to suitable habitats in North America.

As wolf populations have rebounded, scientific studies of them have also flourished. But there hasn't been a systematic, comprehensive overview of wolf biology since 1970. In Wolves, many of the world's leading wolf experts provide state-of-the-art coverage of just about everything you could want to know about these fascinating creatures. Individual chapters cover wolf social ecology, behavior, communication, feeding habits and hunting techniques, population dynamics, physiology and pathology, molecular genetics, evolution and taxonomy, interactions with nonhuman animals such as bears and coyotes, reintroduction, interactions with humans, and conservation and recovery efforts. The book discusses both gray and red wolves in detail and includes information about wolves around the world, from the United States and Canada to Italy, Romania, Saudi Arabia, Israel, India, and Mongolia. Wolves is also extensively illustrated with black and white photos, line drawings, maps, and fifty color plates.

Unrivalled in scope and comprehensiveness, Wolves will become the definitive resource on these extraordinary animals for scientists and amateurs alike.

“An excellent compilation of current knowledge, with contributions from all the main players in wolf research. . . . It is designed for a wide readership, and certainly the language and style will appeal to both scientists and lucophiles alike. . . . This is an excellent summary of current knowledge and will remain the standard reference work for a long time to come.”—Stephen Harris, New Scientist

“This is the place to find almost any fact you want about wolves.”—Stephen Mills, BBC Wildlife Magazine

In the Valley of the Wolves: Wildlife Cinematographer Bob Landis

Emmy Award-winning wildlife cinematographer Bob Landis discusses the making of the film, including the ideal circumstances for filming a predation scene; the importance of spending a vast amount of time in the field; the uniqueness of Yellowstone’s Druid wolf pack, and more.

Full video, Parts 1 and 2:

Watch In the Valley of the Wolves on PBS. See more from Nature.

Watch In the Valley of the Wolves on PBS. See more from Nature.

Tuesday, January 10, 2012

Are Wolves Saving Yellowstone’s Aspen Trees from Elk?

Previous research has claimed that the reintroduction of wolves to Yellowstone National Park in 1995 is helping restore quaking aspen in risky areas where wolves prowl. But apparently elk hungry for winter food had a different idea.

They didn’t know they were supposed to be responding to a “landscape of fear.”

According to a study set to be published this week in Ecology, a journal of the Ecological Society of America, the fear of wolf predation may not be discouraging elk from eating aspen trees after all.

Previous thinking went like this: Aspen are not regenerating well in Yellowstone National Park. Elk eat young aspen. But wolves eat elk. Elk will learn to avoid high-risk areas that wolves frequent. Plants in those areas – such as aspen – will then get a chance to grow big enough so that elk cannot kill them. Eventually, an entire habitat is restored because of a landscape of fear.

Over the last 15 years, the reintroduction of wolves in Yellowstone was heralded as a great success, not only because it reestablished the species, but also because wolves were expected to help restore a healthier ecosystem through such cascading indirect effects on other species.

But this recent study led by Matthew Kauffman, a U.S. Geological Survey scientist, suggests that aspen are not benefitting from the landscape of fear created by wolves, and that claims of an ecosystem-wide recovery of aspen are premature.

“This study not only confirms that elk are responsible for the decline of aspen in Yellowstone beginning in the 1890s, but also that none of the aspen groves studied after wolf restoration appear to be regenerating, even in areas risky to elk,” said Kauffman.

Because the fear of wolves does not appear to be benefiting aspen, the authors conclude that if the Northern Range elk population does not continue to decline -- their numbers are 40 percent of what they were before wolves -- many of Yellowstone’s aspen stands are unlikely to recover. “A landscape-level aspen recovery is likely only to occur if wolves, in combination with other predators and climate factors, further reduce the elk population,” Kauffman said.

Predators play an important role in ecosystems, said Kauffman, and can influence plants by altering how many herbivores there are (by eating the herbivores) or by changing the behavior of herbivores (deterring them from areas where predators lurk). He adds, however, that considerable scientific debate exists regarding the importance of these two ways in which predators influence their prey. And this is especially true for large carnivores.

To complicate matters, predators use different hunting strategies – there is the sit-and-wait strategy (as with a spider in a web, or a rattlesnake waiting for a mouse to leave its burrow) and the more active, go get ’em strategy (think cheetahs and wolves). “So, given that it takes a lot of energy to avoid a predator – energy that could be used to stave off winter starvation – we wanted to find out whether the prey of active-hunting predators such as wolves demonstrated risk-induced changes in areas where they foraged for food,” Kauffman said.

To do this, the authors analyzed tree rings to discern when, in the last century, aspen stands stopped regenerating, examined whether aspen stands have begun to regenerate now that wolves have been reintroduced to the park and tested whether any differences in aspen regeneration were occurring in areas considered safe or risky for foraging elk. They used a landscape-wide risk map of elk killed by wolves over the first 10 years of wolf recovery. Finally, the authors experimentally fenced in young aspen suckers to compare the protection afforded to them by wolves versus that of a physical barrier that prevented elk browsing.

“The results were surprising and have led us to refute several previous claims regarding interactions among wolves, elk and aspen in Yellowstone,” Kauffman said.

The tree rings showed that the period when aspen failed to regenerate (1892 to 1956) lasted more than 60 years, spanning periods with and without wolves by several decades. “We concluded from this that the failure of aspen to regenerate was caused by an increase in the number of elk following the disappearance of wolves in the 1920s rather than by a rapid behavioral shift to more browsing on aspen once wolves were gone from the park,” said Kauffman.

Surveys of current conditions indicated that aspen in study stands exposed to elk browsing were not growing to heights necessary to make them invulnerable to elk. The only places where suckers survived to reach a height sufficient to avoid browsing were in the fenced-in areas. In addition, aspen stands identified as risky from the predation risk map were browsed just as often as aspen growing in less risky areas.

“This work is consistent with much of what researchers have learned from studying wolves and elk in Yellowstone,” Kauffman said. “Elk certainly respond behaviorally to the predation risk posed by wolves, but those small alterations to feeding and moving across the landscape don’t seem to add up to long-term benefits for aspen growing in areas risky to elk.”

The paper, Are wolves saving Yellowstone’s aspen? A landscape-level test of a behaviorally mediated trophic cascade, will be published online in Ecology this week. Co-authors on the study are Matthew Kauffman (USGS), Jedediah Brodie (University of Montana) and Erik Jules (Humboldt State University).

Resident elk attract wolves to Wyoming rangelands

Wolves in Wyoming and elsewhere in the Rocky Mountain West are often lethally removed when they kill domestic livestock. New research out of the USGS Wyoming Cooperative Fish and Wildlife Research Unit indicates that the migratory patterns of the wolf’s primary prey (elk) can influence wolf predation on cattle. Researchers tracked wolves in areas occupied by migratory and resident elk and recorded the location where wolves killed elk, deer, and cattle. They found that wolves stay close to the growing numbers of resident elk, but kill cattle when pasture rotations cause them to comingle with elk. Study findings point to the need to integrate the management of wolves, elk and cattle on western rangeland

Dramatic Links Found Between Climate Change, Elk, Plants, and Birds

Climate change in the form of reduced snowfall in mountains is causing powerful and cascading shifts in mountainous plant and bird communities through the increased ability of elk to stay at high elevations over winter and consume plants, according to a groundbreaking study in Nature Climate Change.

The U.S. Geological Survey and University of Montana study not only showed that the abundance of deciduous trees and their associated songbirds in mountainous Arizona have declined over the last 22 years as snowpack has declined, but it also experimentally demonstrated that declining snowfall indirectly affects plants and birds by enabling more winter browsing by elk. Increased winter browsing by elk results in trickle-down ecological effects such as lowering the quality of habitat for songbirds.

The authors, USGS Montana Cooperative Wildlife Research Unit scientist Thomas Martin and University of Montana scientist John Maron, mimicked the effects of more snow on limiting the ability of elk to browse on plants by excluding the animals from large, fenced areas. They compared bird and plant communities in these exclusion areas with nearby similar areas where elk had access, and found that, over the six years of the study, multi-decadal declines in plant and songbird populations were reversed in the areas where elk were prohibited from browsing.

"This study illustrates that profound impacts of climate change on ecosystems arise over a time span of but two decades through unexplored feedbacks," explained USGS director Marcia McNutt. "The significance lies in the fact that humans and our economy are at the end of the same chain of cascading consequences."

The study demonstrates a classic ecological cascade, added Martin. For example, he said, from an elk’s perspective, less snow means an increased ability to freely browse on woody plants in winter in areas where they would not be inclined to forage in previous times due to high snowpack. Increased overwinter browsing led to a decline in deciduous trees, which reduced the number of birds that chose the habitat and increased predation on nests of those birds that did choose the habitat.

"This study demonstrates that the indirect effects of climate on plant communities may be just as important as the effects of climate-change-induced mismatches between migrating birds and food abundance because plants, including trees, provide the habitat birds need to survive," Martin said.

The study, Climate impacts on bird and plant communities from altered animal-plant interactions, was published online on Jan. 8 in the journal Nature Climate Change.