When their numbers are threatened, Coyotes have larger litters.
Coyotes are the most common large predators in America, and despite intense government and private efforts to eradicate them, coyote populations have remained resilient and spread into cities and suburbs across the country.
In a New York Times story, Dan Flores, author of “Coyote America: A Natural and Supernatural History,” writes that “no other wild animal has suffered the kind of deliberate and casual persecution we have rained down on coyote.” Throughout the Twentieth Century coyotes were designated for eradication by the federal government and many states still hold coyote killing contests. Project Coyote, an animal welfare organization, estimates we are still killing more than half a million coyotes a year. Coyotes will kill and eat unprotected livestock and very rarely attack humans.
Flores explains why coyote populations have grown and spread despite such relentless killing. He reports the findings of biologists Fred Knowlton and Guy Connolly who researched the survival mechanisms the coyotes evolved when their numbers were threatened. They breed younger and have larger litters. If alpha females die, beta females breed. They engage an adaptation called fission–fusion, in which packs break into pairs and individuals that range into new areas and start new colonies. Flores reports scientists have found coyotes can withstand a 70 percent yearly kill rate without any loss in their total population.
Ironically, he adds, left alone, they stabilize their own populations. Though despised by ranchers and farmers, he writes, coyotes are intelligent social creatures that have played an important role in nature for five million years. A New York Times story by Carol Kaesuk Yoon notes Native American mythologies celebrated the coyote as the Trickster, a mercurial figure that could be god-like or perverse. In Navajo tradition the coyote was God’s dog. Coyotes have interbred successfully with wolves and domestic dogs, Yoon reports, and their adaptability is also reflected in their eclectic tastes in food.
Dr. Laura Prugh, wildlife ecologist at the University of Washington, has noted the difficulty of studying these elusive creatures because of their their skill at evading humans, and she has also noted the uselessness of killing for population control. “Killing coyotes is kind of like mowing the lawn,” she told the New York Times six years ago. “It stimulates vigorous new growth.”
Other animal populations remain robust despite eradication effort, according to several scientists who cite the “vacuum effect.” The Humane Society of the U.S. and the Nevada Humane Society report when humans remove a portion of an animal population from its habitat, immigrant animals of the same species move in. Many researchers have statistics to show that killing feral cats does not reduce feral cat populations. Dr. Kate Hurley, a veterinarian who began her career as an animal control officer and became an expert in animal shelter medicine, also became convinced that catching and killing feral cats is useless as well as cruel. She co-founded the Million Cat Challenge and works to spread the practice of trap, neuter and release, which she believes is more humane and more effective. Dr. Hurley says lessons learned about coyotes also apply to cats, and that it was the work of the biologist Fred Knowlton that inspired her to re-evaluate the futility of lethal cat control. Listen to the August 26 PlexusCall to learn more about the entwined complexities of changing organizational practices, and human attitudes and animal behavior.