After an 80-year absence, gray wolves have returned to Colorado − here's how the reintroduction of this apex predator will affect prey and plants

(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.)

Joanna Lambert, University of Colorado Boulder

(THE CONVERSATION) Gray wolves were reintroduced to Colorado in December 2023, the latest attempt in a decadeslong effort to build up wolf populations in the Rocky Mountain states. SciLine interviewed Joanna Lambert, professor of wildlife ecology and director of the American Canid Project at the University of Colorado Boulder, who discussed how and why gray wolf populations declined in the U.S. and the value of reintroducing them to ecosystems in the West.

Below are some highlights from the discussion. Answers have been edited for brevity and clarity.

How can protecting gray wolf populations affect ecosystems?

Joanna Lambert: Apex predators, and predators in general, are disappearing from landscapes around the planet.

Without apex predators, their prey species can become overly abundant. But when apex predators are reintroduced, prey populations decrease and vegetation can rebound. So in certain habitats of Yellowstone National Park, plant species such as willow and aspen are now in greater abundance since wolves were reintroduced in the 1990s. This denser vegetation can provide nesting areas for certain bird species...