The Ecology of Fear – KQED/QUEST (2014)

The return of wolves had a profound impact on vast wilderness areas in North America. Biologist Aaron Wirsing explores why wolves and other top predators are necessary for maintenance of diversity in ecosystems. Using a “deer-cam” Wirsing is quantifying some of the behavioral relationships between predator and prey. Wildlife cameras provide unprecedented opportunities to view social lives of many wild animals including mountain lions.

The gray wolf is one of the world’s most adaptable and widely distributed mammals, ranging over much of Asia, Europe, and North America. Wolves, are pack-hunting predators that sometimes kill livestock. Their nocturnal behavior and haunting howling has resulted in a negative image reinforced with folk tales such the “Little Red Riding Hood.” There is a long history of conflict with exponentially increasing human populations. Over the centuries human-dominated lands have expanded into wolf habitat.

Connections between apex predators and biodiversity is becoming more clear as observations accumulate. Since 2008, wolves have been returning to Washington and have reestablished populations in the U.S. northern Rockies. The impact of wolves on deer populations and vegetation in Yellowstone National Park is striking. Deer have over-browsed plants for decades in the absence of gray wolves. One consequence of deer eating trees along streambeds is less habitat for birds, and streams that are more likely to harbor fewer cold-water fish like trout because they are filled with sediments from soil erosion and overheated because of lack of shade. Return of the wolves positively affecting beaver populations which speed up the restoration of rivers with their hydro-engineering skills.

The impact of predators operates at another behavioral level. Predators do not only consume herbivores. They instigate fear and slow down the grazing and browsing efficiency of plant eaters. The sheer presence of predators puts a break on herbivore feeding frenzy forcing them to be more vigilant. This is know as the “ecology and landscape of fear.”

Wolf restoration in the Northern Rocky Mountains (NRM) has been an amazing success thanks to the cooperative efforts of Federal, State, and Tribal agencies, conservation groups, and private citizens; including ranchers, sportsmen, and outfitters.

The wolf population in Northern Rocky Mountains continue to hold steady. As of December 31, 2015, there were at least 1,704 wolves in 282 packs (including 95 breeding pairs) in Montana, Idaho and Wyoming. An additional 200 wolves in 34 packs (including 19 breeding pairs) were estimated in Oregon and Washington. Wolf numbers continue to be robust, stable and self-sustaining in the Northern Rocky Mountains.



You can be the first one to leave a comment.

Leave a Comment


shared on