Wolves introduced back to Yellowstone

The Ritchey Natural Science Lecture Series hosted Ecosystem: Effects of Wolves in Yellowstone National Park (YNP) presented by guest speaker, Dr. Douglas W. Smith.

Smith is the project leader for the Yellowstone Gray Wolf Restoration Project in Yellowstone National Park. Smith spoke about his time spent working as a biologist for the project from 1994-1997, and his experience with the program since its inception.

He has also studied wolves for 27 years, and prior to Yellowstone, he worked on Isle Royale from 1979-1992. In addition he worked with wolves in Minnesota in 1983. Smith has produced numerous publications on the subject of the wolf and the beaver, as well as contributing many hours of lecture time on both topics.

"There is no substitute for direct experience with your study subjects," Smith said."There's no substitute for getting out in the field and getting intimate with your animals. If you're going to study them, you have to know them."

Smith presented a general foundational biology lecture on Yellowstone wolves involved in his project, which includes forty-one wolves from Canada that were reintroduced to Yellowstone, in 1995 and 1996 after nearly a 70-year absence. The idea of bringing wolves back to Yellowstone deliberately without natural immigration was not received well by many people. There has been a very polarized debate that has been a constant story of wolves.

"The folklore, the misinformation about wolves is ramped - what people want to believe about them, what their value system is," Smith said.

He said contrary to what many people may think, wolves are very selective killers, who strategize and evaluate their kill and are not willing to just kill anything.

"The most interesting aspect for me was the different conclusions each side of the wolf reintroduction issue can come to, using the same data for elk population dynamics," said WSU zoology senior Katie Ricks. "It is so important to look at other possible contributing factors with issues like these."

Smith said wolves are viewed with controversy.

"They lived everywhere north of the equator originally, and they have been pretty much eradicated from most of that area because of conflicts with humans," Smith said. "They also have been in competition with human hunters and have been viewed as dangerous."

Smith's study followed the lifetime reproduction success of 44 different females.

"We got the chance to deal with individual wolves," Smith said. "A lot of wildlife management deals with populations, but since the beginning, we were able to get to know and track individual wolves. This is something that has continued on to this day."

The project is being studied long-term.

"80 percent of wildlife studies last from 2-3 years," Smith said. "We are in our 13th year, so that's getting to be a truly long-term data set."

More than 50% of the wolf studies in North America have studied the impact of wolves on their prey, yet Smiths project focused on other areas of study. He and his crew primarily used the strategy of flying in helicopters to evaluate the wolves. The crew uses collars that report the wolf's location to a satellite, which e-mails the information to Smith's office computer.

"This technology has helped us considerably," Smith said. "This has shown us how territorial the wolves are."

The project also involved getting DNA samples, studying the wolves' behaviors, territoriality, kills, demographics, measure of size, weight and how these effects change over time. Smith and his crew spent much time following and catching wolves, and then taking their samples.

"The stories of wolf's lives are almost always shown in their teeth," Smith said, "You can tell if they have lived in a pack."

He said two wolf sub-systems were studied; the northern range and the interior wolves, and the prey selection between these tow sub-systems. Smith said the killing rate and prey selection are closely linked to the amount of snowfall in the winter. Multiple years of drought appear to be affecting elk condition, and in turn wolf predation.

Weather and climate have a huge factor on the wolves' killing of elk. Conditions of adult elk entering winter, as measured by amount of fat in bone marrow, has been declining thought time and is correlated with winter snowfall.

"Therefore, I hypothesize a climate effect on the wolf-elk-bison relationship that is related to snowfall and summer precipitation," Smith said.

Smith explained how the wolf-prey interactions have wide-ranging influence on the ecosystem. YNP presents an ideal opportunity to examine pre- and post-wolf ecosystem effects because data are available on wildlife populations and vegetation since the late 1800's. Wolves may be having significant effects on Yellowstone ecosystem structure and function. Wolf ecosystem has taken two forms, a terrestrial trophic cascade, and effects on community ecology. After being suppressed for nearly a century, willows have released approximately 2-3 years post wolf reintroduction.

"This occurred despite elk being artificially controlled to 25%of their current population prior to wolf reintroduction," said Smith.

Walter Scott, WSU computer science senior, said he sees the benefits of the lecture.

"This provides a glimpse of what we have yet to learn as a result of protecting at-risk species around the world," Scott said.