Fear of large predators brings bobcats and coyotes into close contact with humans, who are even more likely to kill small carnivores than wild predators.
Overhunting reduced US populations of wolves and cougars to a fraction of their former abundance in the 1900s. Since then, protections under the US Endangered Species Act have helped both species survive. restore regularly. Because wolves and cougars prey on bobcats and coyotes, the researchers predicted 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 his colleagues tracked the movements of 22 wolves (Canis lupus), 60 cougars (concolor puma), 35 coyotes (Canis latrans) and 37 bobcats (Bobcat) using GPS collars between 2017 and 2022. They tracked the animals through two wooded areas in Washington state dotted with roads, ranches, homes and small towns.
When wolves and cougars moved through an area, bobcats and coyotes seemed to avoid larger predators. They spent more time near developed, human-populated areas that wolves and cougars typically avoid. But that decision 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 humans.
“A few coyotes and bobcats were shot while trying to raid chicken coops,” says Prugh, and others were shot on sight or snagged in traps. They found that humans killed between three and four times more small carnivores than large predators.
Prugh says previous studies of small carnivores suggested a strong fear of people, “so from that perspective, we were a bit surprised that they turned to humans more in the presence of large carnivores.” The finding that areas populated by humans were more deadly to small carnivores suggests that the phenomenon known as the “human shield effect”, in which some animals seek refuge near people, can be lethally self-destructive.
Fleeing top predators for human-dominated spaces backfires on bobcats and coyotes by making them more vulnerable to human death, says Robert Anderson at the University of Washington in Seattle who was not involved in the work. “Small predators are not able to accurately assess the mortal danger posed by humans.”