Why Atlanta (and Other Cities) Are Better Because of Coyotes

By Christopher B. Mowry, Ph.D.
September 2024

Over the past 50 years, we have learned much about the beneficial role that predators play in ecosystems and the ecological consequences that occur if they are removed. From the Arctic to the tropics, and in aquatic to terrestrial environments, the same rules of nature apply. Top (apex) predators keep other species lower on the food chain (i.e., consumers) in check and prevent them from degrading the habitat through overconsumption. Robert Paine’s classic ecological studies in the Pacific Northwest intertidal zone in the 1960s, where sea stars (starfish) are the apex predators, dramatically showed the effects of what he termed “downgrading” (Paine 1966). When Paine artificially removed starfish from the ecosystem, biodiversity decreased as a result of mussels outcompeting all other species. Without sea stars to control their numbers, the mussel population soared at the expense of the remaining seven subordinate species. Similar effects have been seen in the absence of other top predators, including sea otters in Pacific kelp forests (Estes and Palmisano 1974), predatory fish in California streams (Power 1990), and gray wolves in Yellowstone National Park (Smith et al. 2003). Terrestrial predators also serve human interests through beneficial effects such as rodent control, disease prevention, and the promotion of diverse plant communities and soil fertility.

The systematic reduction of red (Canis rufus) and gray (Canis lupus) wolf populations via trapping and killing by humans across North America over the past century has led to a downgrading effect in eastern deciduous forests. White-tailed deer populations have exploded across the east in the absence of wolves, leading to an overconsumption of vegetation in many places. The extirpation of wolves also paved the way for eastward range expansion by coyotes (Canis latrans). Coyotes are smaller and more omnivorous than wolves, but they now serve in some ways as the top predator in the absence of wolves throughout much of the U.S. However, because of their smaller size (generally 25-40 lbs.), coyotes are not equipped to routinely take down large prey like adult white-tailed deer. Our research through the Atlanta Coyote Project includes an abundance of data showing the long-term coexistence of deer and coyotes at the same location, as well as instances of deer chasing coyotes (i.e., the prey chasing its supposed predator). Nevertheless, coyotes can and will prey upon fawns, when given the opportunity. We have also found a strong, positive correlation between the presence of stable coyote groups and high levels of biodiversity (Mowry and  Wilson 2019). The coyote as a predator is helping to control the populations of smaller consumers, thereby minimizing the effects of downgrading.

Coyotes strive to form stable male-female pairs who will remain together for life, much like humans. Why do coyotes do this? In other words, what’s in it for the male to remain with the female after mating? The answer is that evolution has selected for this trait as a way to increase pup survival. The male’s participation in pup-rearing (by providing protection and resources) increases his own genetic fitness, allowing him to pass on his genes. In addition, older siblings (i.e., pups born in previous years) can remain within their natal group to help raise younger siblings and avoid having to compete for their own territory and mate. This is a way to increase their genetic fitness, a process known as kin selection. In addition, the stable family group helps to keep litter sizes small. Only the adult male-female pair breeds and younger subordinate members of the family (if they have remained) are suppressed from reproducing. If this family group is disrupted by lethal management, it eventually leads to larger litter sizes. This is just basic biology. Transient coyotes on the landscape (those who have left their natal group and don’t yet have a mate and territory) are looking for the opportunity to increase their genetic fitness through reproduction. Any subordinate coyotes who survive hunting pressure are now no longer being suppressed from breeding, will then mate and have their own litters of pups. Control of coyotes by hunting means that there is less competition among those who remain and more available resources, which allows females to produce more offspring and the population ultimately increases. This is the unintended ecological consequence of attempts at lethal management.

So how do humans and coyotes co-exist and avoid conflict? The best advice is to limit access to food and be a responsible pet owner. Contrary to popular belief, there aren’t large numbers of coyotes in our cities, and they are usually not on the prowl to eat our pets. Most people hear coyotes before, or if, they ever see them and what often sounds like many is actually just a few. Coyotes have an uncanny ability to produce a variety of yips, barks, and howls, which tell rivals to stay away and make the group size sound larger than it really is. The coyote’s omnivorous diet primarily consists of small mammals like squirrels and chipmunks, insects, and fruit. Dogs and cats are not natural menu items, but when people let pets roam freely, leave food outside for pets, or overfill bird feeders that attract small mammals, coyotes can come calling looking for an easy meal. With some simple steps, people can help to maintain the natural reticence that coyotes have towards humans and prevent chance encounters with pets.

Humans began domesticating wild canids nearly 30,000 years ago, which eventually led to “man’s best friend.” Coyotes are close relatives of modern-day dogs (Canis familiaris) and people often mistake coyotes for dogs at first glance. We love dogs, so why not coyotes? They are resourceful, adaptable animals who form strong family bonds – again, much like humans. We should respect their resilience, appreciate the ecosystem services they provide, and honor their presence as a true native American species.

Dr. Chris Mowry is a Professor of Biology at Berry College, where he teaches courses in Zoology, Ecology, and Conservation Biology. He is the co-founder of the Atlanta Coyote Project with Dr. Larry Wilson and has been conducting research on coyotes since 2002.

Resources:

Atlanta Coyote Project. https://www.atlantacoyoteproject.org.

Estes, J.A. and J.F. Palmisano. 1974. “Sea otters: their role in structuring nearshore communities.” Science. 185: 1058-1060.

Mowry, C.B. and L.A. Wilson. 2019. “Species richness within an urban coyote (Canis latrans) territory in Atlanta, Georgia, USA.” Urban Naturalist. 27: 1-14.

Paine, Robert T. 1966. “Food web complexity and species diversity.” The American Naturalist. 100, 910: 65-75.

Power, M.E. 1990. “Effects of fish in river food webs.” Science. 250: 811-814.

Smith, D.W., R.O. Peterson, and D.B. Houston. 2003. “Yellowstone after wolves.” BioScience. 53(4): 330- 340.