Fear of large predators is pushing bobcats and coyotes into close contact with humans, who are even more likely to kill small carnivores than wild predators.
Overhunting drove US wolf and cougar populations to a small portion of their former abundance in the 20th century. Since then, protections under the US Endangered Species Act have helped both species make a steady recovery. Because wolves and cougars prey on bobcats and coyotes, the researchers anticipated that the return of these large predators would control the number of smaller animals.
Investigate, laura prugh at the University of Washington in Seattle and colleagues tracked the movements of 22 wolves (canis lupus), 60 cougars (puma concolor), 35 coyotes (canis latrans) and 37 wildcats (lynx rufus) using GPS collars between 2017 and 2022. They followed the animals through two forested regions of Washington state dotted with roads, ranches, homes, and small towns.
When wolves and cougars moved into an area, bobcats and coyotes appeared to avoid larger predators. They spent more time near developed, human-populated areas that wolves and cougars tend to avoid. But this move often had fatal consequences: About half of the coyotes and most of the bobcats that died during the five-year study period were killed by people.
“Some coyotes and bobcats were shot while trying to raid chicken coops,” Prugh says, and others were shot on the spot or caught in traps. They found that humans killed three to four times as many small carnivores as apex predators.
Prugh says previous studies on small carnivores suggested a strong fear of people, “so from that perspective, we were a bit surprised that they shifted more toward humans in the presence of large carnivores.” The finding that human-populated areas were deadlier to small carnivores suggests that the phenomenon known as the “human shield effect,” in which some animals seek shelter near people, may backfire lethally.
Fleeing top predators into human-dominated spaces backfires on bobcats and coyotes by making them more vulnerable to human kill, he says rober anderson at the University of Washington in Seattle who was not involved in the work. “Smaller predators cannot accurately assess the deadly danger posed by humans.”