Olympic Cougar Project members work to replace the GPS collar on Lilu, a wild cougar, near Port Angeles, Washington, U.S., December 14, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

Lilu, a wild cougar, hides up a tree near Port Angeles, Washington, U.S., December 14, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A kill site in a former cougar den is seen near Sequim, Washington, U.S., December 16, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Kim Sager-Fradkin prepares a tranquilliser dart for Lilu, a wild cougar, near Port Angeles, Washington, U.S., December 14, 2021. "The collaring piece gives us information that we just could not get in any other way," said Sager-Fradkin, a wildlife biologist hired by the Lower Elwha Klallam Tribe. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Lilu, a wild cougar, is sedated and measured by members of the Olympic Cougar Project, near Port Angeles, Washington, U.S., December 14, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

Glen Kalisz, habitat connectivity biologist with the Washington State Department of Transportation, checks a trail camera that generates data about habitat connectivity for cougars near Olympia, Washington, U.S., December 17, 2021. Some 100,000 cars travel along I-5 each day, blocking cougars and other wildlife from crossing to the other side of the freeway. "It is likely one of the worst barriers for all species in the state," said Kalisz. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Vanessa Castle, a member of the Olympic Cougar Project, looks for Lilu, a wild cougar, using a tracking device that detects radio waves near Port Angeles, Washington, U.S., December 13, 2021. "As an indigenous person, we are taught that we have to walk in two worlds, one of our traditional sense and one of the modern day sense," said Castle, a Lower Elwha Klallam tribal member who works for the project. "I think it changes the way these scientists think about these animals."?? REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A dog pokes his head out of a "hound box" near Port Angeles, Washington, U.S., December 13, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. TPX IMAGES OF THE DAY 

Kim Sager-Fradkin speaks on a walkie talkie to other members of her cougar tracking team near Port Angeles, Washington, U.S., December 13, 2021. "The collaring piece gives us information that we just could not get in any other way," said Sager-Fradkin, a wildlife biologist hired by the Lower Elwha Klallam Tribe. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A view of the mountains of the Olympic Peninsula near Port Angeles, Washington, U.S., December 13, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Andy Stratton, 27, senior file technician and member of the Olympic Cougar Project, holds onto his dogs before tracking Lilu, a wild cougar, near Port Angeles, Washington, U.S., December 14, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Read Barbee, 23, a field technician and member of the Olympic Cougar Project, tracks Lilu, a wild cougar, using a device that that detects radio waves near Port Angeles, Washington, U.S., December 14, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Olympic Cougar Project members climb off trail to track Lilu, a wild cougar, near Port Angeles, Washington, U.S., December 14, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Kim Sager-Fradkin and Mark Elbroch, scientists with the Olympic Cougar Project, look over a former cougar den for scientific data near Sequim, Washington, U.S., December 16, 2021. "Without a doubt, mountain lions increase the health of ecosystems," said Elbroch. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A computer screen showing GPS tracking for Lilu, a wild cougar, up until the GPS collar stopped functioning, is seen near Port Angeles, Washington, U.S., December 13, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Mark Elbroch, a member of the Olympic Cougar Project and scientist for Panthera, points out a cougar print near Sequim, Washington, U.S., December 16, 2021. "Without a doubt, mountain lions increase the health of ecosystems," said Elbroch. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Dave Manson (centre), project biologist and member of the Olympic Cougar Project prepares to dart Lilu, a wild cougar, with a tranquilliser near Port Angeles, Washington, U.S., December 14, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Olympic Cougar Project members work to replace the GPS collar on Lilu, a wild cougar, near Port Angeles, Washington, U.S., December 14, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Sara Cendejas-Zarelli, a project biologist and a member of the Olympic Cougar Project takes notes during a wild cougar capture near Port Angeles, Washington, U.S., December 14, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Glen Kalisz, habitat connectivity biologist with the Washington State Department of Transportation shows a photo of a cougar taken by the trail camera, next to the I-5 freeway near Olympia, Washington, U.S., December 17, 2021. Some 100,000 cars travel along I-5 each day, blocking cougars and other wildlife from crossing to the other side of the freeway. "It is likely one of the worst barriers for all species in the state," said Kalisz. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Lilu, a wild cougar, leaves after the battery on her GPS collar has been replaced by members of the Olympic Cougar Project near Port Angeles, Washington, U.S., December 14, 2021. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Glen Kalisz (left), habitat connectivity biologist with the Washington State Department of Transportation, and Andy Stratton (centre), senior field technician at Panthera, walk next to I-5 freeway as they gather data about habitat connectivity for cougars, near Olympia, Washington, U.S., December 17, 2021. Some 100,000 cars travel along I-5 each day, blocking cougars and other wildlife from crossing to the other side of the freeway. "It is likely one of the worst barriers for all species in the state," said Kalisz. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Traffic on the I-5 freeway is seen near Olympia, Washington, U.S., December 17, 2021. Some 100,000 cars travel along I-5 each day, blocking cougars and other wildlife from crossing to the other side of the freeway. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Glen Kalisz, habitat connectivity biologist with the Washington State Department of Transportation, shows data he collected about cougar habitats near Olympia, Washington, U.S., December 17, 2021. Some 100,000 cars travel along I-5 each day, blocking cougars and other wildlife from crossing to the other side of the freeway. "It is likely one of the worst barriers for all species in the state," said Kalisz. REUTERS/Stephanie Keith SEARCH "KEITH WASHINGTON COUGARS" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES