Human Impact on Apex Predators
By Oran Lichtman, Be Green Living Intern
Apex predators, like wolves, bears, and large cats provide a crucial role in their environment, they act as a “top down” control mechanism keeping prey species in check (Openstax, 2021). They are at the proverbial “top of the food chain” and usually have few to zero predators that prey on them. In the context of ecological population dynamics, large predators regulate the population of many herbivorous species like deer and small rodents. This regulation then inadvertently affects plants species, and all other associated organisms, in what’s called a trophic cascade, taking off some of the pressure the herbivores put on plants by eating them.
These days these large predators are facing many pressures themselves and the largest one, amongst many others, are humans. Not only do humans actively hunt these animals, but habitat loss of their native ranges cuts areas into smaller and smaller pieces, fragmenting populations. This fragmentation cuts the size of the gene pool and pushes species into new areas causing them to meet species they have never historically met. Polar bears in the Arctic have come further south into Canada and have met and hybridized with grizzly bears, producing what is popularly called the grolar bear (Line, 2008).
Another example, which hits closer to home, is the eastern coyote. Many people know it as the “coywolf” or the “coydog” but what this canid actually is is something very indicative of the modern human – carnivore interaction. The eastern coyote began as the coyote from the prairies in the west and was mostly confined there since other predators outcompeted it in forested environments. However, as humans developed once remote areas into agricultural and urban landscapes this species has changed and adapted to new environments and new areas. In fact, they have been so successful at adapting to us that they have been able to thrive and move into every state within the continental United States (NPS).
As industrial/ agricultural areas expanded the land that other predatory animals shrank. Wolves, large cats, and other predatory species were pushed out and extirpated, meaning the species has gone extinct in a specific area. This allowed these coyotes able to find their own niche within these newly developed areas. They were able to move out of the prairie and into urban settings with the fist sightings happening in the 1940s. One population moved across the north and another through the south where they met and interbred with other canid species, which is where the “coydog” and “coywolf” moniker comes from (NPS). As they spread eastward, they came into contact with eastern wolves, gray wolves, and feral domestic dogs intermixing with each species, which may mean they are on a trajectory to become their own (NPS). The eastern coyote is so indicative of the human – carnivore experience because in a culmination of pushing those species that control coyote populations out, via habitat loss, hunting, etc the coyote was able to take advantage of a lack of competition and tap into the gene pool of other dwindling species. The historical response to the presence of predators is through control, hunting and bounties (Leopold, Chamberalin 2002), which also aided in helping big cats’ and wolfs’ decline. So, it could be said that the eastern coyote is not just indicative, but also a product of our past with these species.
Before the study of wildlife management became more deeply studied the typical response to large carnivores, as mentioned before, was to trap and kill. Many predatory animals were seen as threats to survivorship because they would hunt livestock and compete with humans for food. More recently however, as more has been discovered about wildlife biology and ecological species interactions management practices have moved from having bounties on these animals to understanding the importance of their roles. Because apex predators control the regulate the population of prey species, as well as other carnivore species they can actually increase species richness and diversity (Leopold, Chamberlain, 2002). They facilitate smaller populations of many different species rather than allowing one species to take over and overwhelm other groups in a certain locale. Take for example the case of Yellowstone Park. Wolves had been hunted out and without them to control the elk population the grasses, trees, and bushes were all eaten before they could re-grow. This meant that there was no habitat for native rabbits to hide form foxes, no trees to hold riverbanks or house bird species, and no food for omnivorous species that rely on fruit for the winter, like the grizzly bear (PBS video, 2015). After they were reintroduced the elk population diminished, and all the plants had a chance to grow back which created more habitat for other species to move in. The wolves were the ones that managed the largest herbivore in the ecosystem and in turn were the keystone that kept the entire ecosystem in balance. Modern predator management takes this into consideration and rather than just hunting to control the population, tagging, relocation, and education are all part of how human society deals with these animals (Urban Coyote Project, 2021).
As more has been, and is being, learned about wildlife biology, management practices are changing to consider the intricacies of all aspects of an ecosystem, especially as our landscape is changing. From hunting to conservation these creatures have a large impact on an ecosystem as a whole and understanding and recognizing that will make for a better relationship for the both of us in the future.
Sources
Urban Coyote Research Project (2021) Coyote Management Practices Coyote Management Strategies | Urban Coyote Research
PBS video, National Geographic (2015) Wolves of Yellowstone Wolves of Yellowstone | National Geographic Society
Maryland Department of Natural Resources (MDNR) (2019) Coyotes in Maryland Coyotes in Maryland
Leopold B., Chamberlain M. Southeast Association of Fish and Wildlife (2002) Predator Control: Here we Go Again leopold-predator_control.pdf (wordpress.com)
National Park Service (NPS) Species Spolight: Eastern Coyote NETN Species Spotlight – Eastern Coyote (U.S. National Park Service) (nps.gov)
MDNR (2016) Coyotes in Maryland: Where they came from and what to expect Coyotes in Maryland: Where they came from and what to expect
Montgomery Parks Living with Wildlife: Living with Coyotes Living With Coyotes (montgomeryparks.org)
Line, L. Audubon (2008) Meet the ‘Grolar Bear’ Meet the ‘Grolar Bear’ | Audubon
Openstax Biology2e 45.6 Communtiy Ecology 45.6 Community Ecology – Biology 2e | OpenStax
About the Author:
Oran Lichtman, Be Green Living Intern
Oran was born and raised in Germantown, Maryland, and is currently pursuing his bachelor’s degree in Environmental Management at University of Maryland Global Campus. After a year studying abroad in Southern Israel he found his passion in sustainability and the community. He is looking forward to taking on his new role as the BeGreen living Intern. After work you can find him either in the kitchen cooking or outdoors hiking with friends.
