Cats and birds are animals fiercely protected by animal lovers, while coyotes have had a more troubled history with people. But a new study shows that coyotes may be playing an important role in keeping cats and birds apart.
The study’s authors, including researchers from the North Carolina Museum of Natural Sciences and N.C. State, used motion-activated cameras to take snapshots of domestic cats and coyotes in backyards, small urban forests, and protected areas such as parks and nature preserves in Raleigh and other parts of the eastern United States. The cameras captured almost no cats in the natural areas the coyotes preferred – good news for the birds and other small animals that make easy prey for cats.
“People are concerned about cats running around in protected areas and killing native species,” said lead author Roland Kays.
Domestic cats have been estimated to kill up to 4 billion birds and 22 billion small mammals a year in the United States.
Cats often prey on common introduced species, such as Norwegian rats. But they are thought to be devastating to native, at-risk species, especially on islands, where feral cats have been linked to extinctions.
Sensitive species are more likely to live in natural areas, like those the coyotes patrolled, said Kays, so in keeping cats out, coyotes are indirect guardians of these animals.
Coyotes themselves may prey on some of these small species, but are more likely eat larger animals and fruit, said Kays.
This study describes some of the first results to come out of the “e-mammal” citizen science project led by the N.C. Museum of Natural Sciences and the Smithsonian Institution. Volunteers set up cameras in their backyards, along trails, in urban forests, and in parks and nature preserves. They also helped identify the animals captured in photographs.
“I was totally surprised” at the extent to which cats avoided places coyotes roamed, said Kays. In half the protected areas, no cats were photographed at all; most of other sites captured images of just one cat apiece.
This was not just a case of pet cats staying close to home, said Kays. Statistically, coyote presence was a better predictor of cat location than housing density.
“Yeah, coyotes can help with the feral cat population, I would definitely agree with that,” said Jonathan Cawley, editor-in-chief of the North Carolina Predator Hunters Association. The organization connects hunters with ranchers and others who want coyotes off their land.
“But I think coyotes are a much bigger problem than cats...I’ve never seen a cat tear a calf out of a mother cow when they’re giving birth,” he said. Coyotes also compete for deer, kill pets and prey on the native fox population, he added.
Kays thinks that coyotes, whose range has expanded from the plains to both coasts and as far north as Alaska, are helping to fill the role the red wolf vacated since its elimination from the Southeast in the early part of the 20th century.
In that way, the coyote-cat-small-prey triad is acting in accordance with the “meso-carnivore release” hypothesis, said Camilla Fox, founder and executive director of the California advocacy group Project Coyote.
The hypothesis suggests that in the absence of large predators such as wolves and coyotes, smaller carnivores including foxes, raccoons and domestic cats will prey unchecked on birds and other small animals.
Cawley disagrees that coyotes are filling a natural place in the ecosystem. Coyotes are now in all 100 counties of North Carolina, he said. “The red wolf didn’t roam the entire state.”
Researchers in southern California also found that more coyotes meant fewer cats; in addition, they found more diverse bird populations in these areas.
Predators have been shown to indirectly affect bird populations in other ways. Camilla Fox pointed to the reintroduction of gray wolves to Yellowstone National Park in the late 1990s, which curbed elk grazing on brush and shrubs, opening up more habitat for birds.
“[The coyote] is the most persecuted, maligned, misunderstood carnivore in North America,” said Fox. When state and federal agencies treat predators such as coyotes as “vermin,” she said, that attitude becomes common to the public.
The extent to which feral cats should be treated as vermin is also controversial.
Animal welfare advocates often argue in favor of the “trap neuter release” method to control feral cat populations.
But some wildlife groups, including the American Bird Conservancy, recommend preventative tactics and euthanasia as more effective and more humane.
“Maybe in terms of the health of our ecosystem, we’re better off having coyotes than nothing,” said Kays.