Wildlife Science in the Field

Wolf Research in Washington \ Learning in Yellowstone

The Wildlife Science program at SEFS covers the basic ecology of free-living animals and their relations to humans, including their management and conservation. Working within a discipline in which field experience is very important, SEFS faculty and students have engaged in varied and wide ranging approaches to “hands-on” learning and research. Examples include a new research project studying wolf recovery in the Methow Valley, led by Assistant Professor Aaron Wirsing, and a decades-old undergraduate field class in Yellowstone National Park, currently led by Professor John Marzluff. 

Wirsing’s project, which begins in August 2012 and is funded over the next five years by the National Science Foundation, will use video from animal-borne cameras to observe two deer species in the Methow Valley that are commonly targeted by wolves as prey. In July 2008, after decades of absence, gray wolves (Canis lupus) were discovered in western Okanogan County, marking the official return of this predator to Washington state. Since then, wolf numbers in Washington have grown, and several packs are now being tracked by State agencies. Says Wirsing, “This presents a unique opportunity to explore the effects of a newly restored top predator on native ecosystems in Washington.  With collaborators Michael Heithaus (Florida International University) and William Ripple (Oregon State University), I will ask whether wolf recovery in the Methow Valley of north-central Washington alters deer foraging behavior and, as a result, reshapes plant communities. The project will also provide support for a graduate student in our program.”

The two deer species that will be studied—mule deer (Odocoileus hemionus) and white-tailed deer (Odocoileus virginianus) have different escape tactics following a predator encounter. Mule deer are relatively slow and use an evasive gait called stotting to escape wolves and other predators. Thus, mule deer perceiving the threat of wolf predation should shift to rough terrain where their agility is advantageous and avoid smooth terrain where escape requires speed. In contrast, white-tailed deer are fleet of foot and escape predators by sprinting away. Thus, when frightened by wolves they should avoid rugged terrain where their speed is neutralized and seek the safety offered by smooth terrain. By implication, recolonizing wolves could initiate cascading effects on plants (“trophic cascades”) via two different pathways by shifting mule deer herbivory to rough terrain (e.g., rugged slopes) and white-tailed deer herbivory to gentle terrain (e.g., valley bottoms and riparian areas).

“To test for this intriguing possibility,” says Wirsing, “We will rely on video from animal-borne cameras to detect deer spatial shifts and foraging adjustments in response to wolves. Our prediction is that deer in areas being hunted by wolves should become more wary and increase their use of safe habitats where they can escape using their specific escape tactics to best advantage.  We’ll also use an exclosure experiment, with paired caged areas and controls, to contrast patterns of deer herbivory in areas with and without wolves to determine whether behavioral responses of frightened deer transmit indirect effects of wolves on plants, or in other words, trophic cascades.”

The project should yield new insights about the behavior of mule and white-tailed deer, in particular by illustrating how these two species react differently to the threat posed by wolves. And, says Wirsing, “The project could change the way top-down effects of predators like wolves are understood by revealing for the first time that the impacts of predators on plant species serving as food for their prey hinge on prey escape tactics.”

ESRM 459, “Wildlife in the Pacific Northwest,” is a small field class that SEFS faculty have led for over three decades between Winter and Spring academic quarters. Under the leadership of now-Emeritus Professor Dave Manuwal, the class took field trips in a variety of locations, including Yellowstone National Park, into which wolves had just been reintroduced. When John Marzluff joined Manuwal in teaching the class in 1999, the primary focus became Yellowstone’s Northern Range—North American’s version of the Serengeti.  Marzluff has led the trip each year since then, joined at times by other faculty, including Gordon Bradley, adding his perspective on park policy and recreation; L. Monika Moskal, adding her expertise in Yellowstone vegetation and remote sensing; and most recently Wirsing, with his focus on predator-prey systems.

Says Marzluff, “This year, 19 ESRM and Biology students returned from the annual spring break field trip to western Montana and Yellowstone National Park.  Having just left the grandeur of the Yellowstone ecosystem and the abundant wildlife it holds,  we hit Spokane—the setting is fine, birds and an occasional deer or elk are added to our lists of fauna, but the traffic seems entirely new. It signals the return to the city and departure from a wilder country, one where animals outnumber cars and students get close up looks at bighorn sheep, deer, pronghorn, elk, wolves, and coyotes. The human pace is in stark contrast to the slow pace of wildlife, and the measured pace of learning first hand from local experts and personal observation.”

During the class students learn how to identify wildlife, study their behavior, and examine the human dimensions of issues that influence wildlife in the West. When they return they analyze data and prepare oral and written presentations of their research. The 2012 class continued work with National Park Service biologists to survey ravens and wolves and study their relationships. The students also began a new project following elk to quantify their vigilance—their head up, ears forward looking for potential predators—and relate this wary behavior to their location in the herd, body condition, and position on the landscape. As in the past, the class met with park biologists studying bison. And, says Marzluff, “This year as we talked about bison we roasted and devoured a succulent deer leg, kindly donated to the cause by Professor Rob Harrison. There is certain charm to watching wildlife as you also eat wildlife!”  

The trip traditionally ends with a meeting with SEFS affiliate faculty Professor Marco Restani of St. Cloud State University and Montana State University professor Al Harmata to catch, band, and study contamination in bald and golden eagles. “Although this was the first year we failed to catch an eagle,” says Marzluff,” we enjoyed our time on the MBarZ ranch talking with lifelong Montana rancher Tom Milesnik, who is candid in discussing his views of predators, people, and the changing West. He has made a number of innovative improvements to his land so that he can raise cattle and provide high quality wildlife habitat. His land teems with deer, pheasants, eagles, and magpies, and his stream is a trophy trout fishery.”

As the class reentered Washington state on March 24, everyone was tired and many slept as the vans crawled west through the sage and wheat, over the Cascades, and back into the green of the Puget Sound lowlands. “As they slept,” says Marzluff, “I’m sure many dreamed of the great adventure we had just completed. They relived the moments just spent staring into the bighorn sheep’s eye, watching wolves ford the Lamar River, or listening to true stewards of the land. These classes, small in size and high in personal contact with the subject and the faculty, are the ones students reminisce about. I suspect they will tell their kids about this trip, just as I tell mine about similar trips I made as an undergraduate.”

 

Animal-borne camera deployed on mule deer during a pilot season in the Methow Valley in February 2011. Note instrumented animal's chin at top of image.

Gray wolf (Canis lupus) in Yellowstone National Park. Photo: National Park Service.


SEFS faculty leaders of ESRM 459, Professer John Marzluff, right, and Assistant Professor Aaron Wirsing, left, in Yellowstone National Park. Photo: Greg Zimmerman.

Setting off for a day's trek in Yellowstone National Park. Photo: Greg Zimmerman.

ESRM students watching for wildlife in Yellowstone National Park. Photo: Greg Zimmerman.

Wildlife viewing in a snowstorm in Yellowstone National Park. Photo: Greg Zimmerman.