Plenty!

Biologists reintroduced wolves to Yellowstone National Park in 1995, and good things have been happening to the ecosystem ever since.

Ongoing research shows that since the wolves’ return, the ecosystem’s variety of wildlife has increased. More Aspen trees are growing, elk herds are healthier, even the people are happier.

Here is why:

More Wildlife
Ecosystems with wolves usually have more rabbits, squirrels, hawks, owls, and other small animals. The reason has to do with how wolves impact coyote populations. Wolves tend to kill coyotes on sight. (Researchers are not sure exactly why.) So when wolves are removed from an ecosystem, coyote populations can skyrocket. Because coyotes hunt small animals, including mice, rabbits, and squirrels, there is less small prey available for smaller predators like hawks and owls. Bringing wolves back into the ecosystem reduces coyote populations and restores them to more reasonable numbers. With coyotes in balance, more rabbits, squirrels, and mice are available as food for more hawks and owls.

Ecosystems with wolves also have more eagles, bears, ravens, and other scavengers. Although a large pack of wolves can consume an entire deer carcass in a matter of hours, they cannot always eat an entire elk at one meal. When the wolves are full, they might bury some food to eat later or abandon the carcass, leaving leftovers for a multitude of scavengers. A bear might also chase wolves away from their kill and take it for himself.

More Aspen Trees
Aspen trees also benefit by having wolves around. With wolves in the area, elk and deer seek the relative safety of the forest’s edge. They avoid the deep forest where wolves can “sneak up” on them and attack. Without wolves around, elk ventured into the deepest parts of the forest, grazing on the tender seedlings. When wolves were returned to Yellowstone, the elk changed their grazing patterns, no longer venturing into the deepest aspen groves. Seedlings were able to take root and grow for the first time in many years.

Healthier Herds
Because healthy, full-grown deer and elk can outrun wolves, wolves rarely waste their energy chasing after them. Instead, they usually pursue old, young, or sick animals, which are easier to catch. Wolves that remove sick animals help to reduce the spread of diseases throughout a herd.

Happier People
Wolf lovers have been packing the park to glimpse the wild wolves...and increasing revenues at area shops, restaurants, and hotels.


To find out more about wolf reintroduction at Yellowstone National Park, visit www.nps.gov/yell/nature/animals/wolf/wolfrest.html.

What Good Are Wolves?