An estimated 10 wolves from Yellowstone National Park have been killed by hunters this month, adversely affecting the park's wolf research program, one of the longest studies of its kind.
"Losing the wolves has been a big hit to us scientifically," says wildlife biologist Douglas Smith, leader of Yellowstone's wolf project, which has tracked the wolves since their reintroduction in 1995. The killings came just as researchers, who are partly funded by a 5-year U.S. National Science Foundation grant, were set to begin the wolf project's annual winter survey of the canids' predatory habits.
The wolves were shot by licensed hunters outside the national park during the legal wolf hunting season that opened this fall in Montana, Idaho, and Wyoming. Seven of the wolves were wearing radio-collars that help scientists track the wolves. Two "were the only collared members of their packs," Smith says. "So, now we can't track those packs." In addition, two of the wolves had specialized GPS collars that collect data every 30 minutes, which has helped researchers better understand wolves' movements and predatory behaviors. Only one wolf in the study program is now left with such a collar.
Smith says that all seven radio-collared wolves were within 1 to 3 miles of the park's unmarked boundary when killed. "We don't know why they left; one had never gone outside before, and three of the others did so only infrequently," he says. The wolves may have been in pursuit of prey, since the park's elk also migrate out of the park at this time of year; or they may have been enticed by the gut piles hunters leave behind after shooting and dressing out an elk. Many professional hunting camps are set up around the park's boundaries close to known elk migration routes. The wolves, too, are used to humans, "which could make them more vulnerable to hunting," Smith says.
The wolves' deaths mark the second time in 3 years that collared Yellowstone research wolves have been shot by hunters. Some worry that hunters are targeting the radio-collared animals. The hunters returned the collars to the park's wolf project.
Although Yellowstone's wolves are protected while they roam inside the park, they now can be legally shot as soon as they set foot outside. Wolves in Montana and Idaho were removed from the federal endangered species list in May 2011; those in Wyoming were downlisted on 30 September. The Wyoming wolf hunting season opened the next day.
While lamenting the loss of the wolves, some of whom were well-known to park visitors, park officials stressed that Yellowstone's wolf population remains healthy, with approximately 88 individuals. "These were loved, iconic wolves," says Dan Hottle, a park spokesperson, but their loss does not "adversely affect our ecosystem." But the wolves' social structure and stability may be affected, Smith says. There could also be an impact on tourism, observers say: A 2006 University of Montana study estimated that the wolves draw in $35 million a year in tourist dollars to the park and surrounding areas.
Scientists predict that the loss of the collared wolves will have a big impact on both the park's research project and numerous other independent studies investigating a variety of issues, such as elk management and ecology. The collars collect data intended to help wildlife managers better understand wolf behavior, particularly the canids' effect on elk. And unless a wolf is wearing a collar, researchers say they can't be sure that it is an animal that uses the park. The killings are "very unfortunate, because of the harm it does to the research," says Bob Ream, a retired wolf biologist from the University of Montana, and chair of the state's Fish, Wildlife & Parks Commission, which oversees the hunts. "I would like to think this was not done intentionally." Intentional or not, Smith notes that of the killed wolves that were known to have used the park, an estimated 70% were wearing collars.
Smith and others, including park officials and conservationists, have lobbied officials in the three states to establish buffer zones around the park to protect the wolves from hunting. Only Montana, however, has made an effort to do so. It has reduced the quota in one hunting district north of the park from 15 wolves to three.
Smith has teams out now in search of the two packs that no longer have collared individuals. "Scientifically, our goal was to study a population of wolves that was not exploited by people," he says. "Unfortunately, that is no longer the case."