Why Predators Matter.
Written by Stephanie Bradley, published March 2018
Photo taken by Bobby Bradley
Why are predators important? And by predators, I mean animals that hunt and eat other animals to survive. The answer may not be what you thought or may be much more complex than you imagined. Predators are an important part of a healthy ecosystem. How you might ask?
Predators hunt and kill the vulnerable prey, such as the old, injured, sick, or the very young leaving more food for the survival and prosperity of healthy prey animals. This is where the saying “survival of the fittest” comes into play. While predators will catch healthy prey when they can, catching the vulnerable prey is often much easier and aids in natural selection. The healthy, strong, and clever prey live to reproduce and pass these great genetics onto their offspring. Also, by preying on the sick and controlling the size of prey populations, predators help slow down the spread of disease.
In addition to keeping prey species healthy and at the top of their game, predators play an important role in resource management. Predators control the size of prey populations making sure there are enough resources to meet the populations’ needs, such as food to eat. If there are too many prey species in a given area and their growth is not controlled they can eat all available food, overgrazing the habitat and making regeneration difficult for the next growing season. This will not only starve the current population, but also limit survival for future generations. Here is a nice summary I found on the Cheetah Conservation Fund’s (CCF) website. As you may know, I used to work for CCF and spent my 3 years in Namibia preaching this information to anyone who would listen. It is true for Namibia and everywhere else in the world.
“If carnivores were removed from an ecosystem, what would happen?
1. Antelope herds would grow and grow.
2. Only bad weather such as a drought, or disease such as rabies, would slow down the herd growth.
3. Large antelope herds would overgraze their food source, and as the food disappeared, the whole herd would begin to starve. [1]”
Especially here in America, we are living with a lack of large predators. We have our ancestors to thank for that. As Europeans colonized America they saw large predators as a threat to themselves, their children, and livestock. Rather than come up with solutions to live alongside these majestic animals they sought to exterminate them from the continent. Quickly began a wide spread extermination campaign against wolves, coyotes, cougars, and bears. [2,3] Many campaigns were run and/or encouraged by our own federal government. And not only were predators being hunted in exorbitant numbers but their habitat was being destroyed for human expansion. Our ancestors may have started the campaign against large predators but they have passed down their fear and misunderstanding about predators to us.
I often hear the argument that here in America and in Africa that human hunters can replace the role of predators by hunting prey populations and preventing overgrazing. While human hunters can help control prey populations, they generally do not remove the injured, sick, old, or very young animals as predators do. Also, human hunters often cannot keep up with the volume of demand, we see an example of this in America where white-tailed deer has overgrazed many of our forests, causing a cascade of negative effects on many other forest species and humans alike [4]. This flimsy argument is why I don’t find the human hunter to be our one and only ecosystem solution, when we have a perfected system (predators) to control prey populations waiting to be allowed to do their job. We need to work with predators instead of against them with a varied approach to wildlife management and conservation. In addition to controlling prey overpopulation and overgrazing, predators’ actions affect other natural resources such as, land formations, herd movement/migrations, and species diversity. Watch this great video, “How wolves change rivers” by Sustainable Human about the gray wolf’s role in ecosystem management in Yellowstone National Park.
References:
[1] Staff, CCF. “Why are predators important?” Cheetah Conservation Fund, 14 May 2011, cheetah.org/2011/05/why-are-predators-important/.
[2] Clemens, Danny. “The Myth of the Predator.” Discovery.com, October 21, 2015. http://www.discovery.com/dscovrd/wildlife/the-myth-of-the-predator-when-fear-becomes-reality/.
[3] Worrall, Simon. “How the most hated animal in America outwitted us all.” National Geographic, 7 Aug. 2016, news.nationalgeographic.com/2016/08/coyote-america-dan-flores-history-science/.
[4] “Deer eating away at our forests nationwide.” NBC News, The Associated Press, 18 Jan. 2005, www.nbcnews.com/id/6835501/ns/us_news-environment/t/deer-eating-away-forests-nationwide/#.WqF5w1Q-feQ.