The Intriguing Field of Wildlife Diseases

Written by: Kyle Lannon

Wildlife disease is a newer field that keeps growing, for we have a greater need to research and understand it in order to better manage and protect our wildlife populations. The reason that this field keeps growing, is that it is such a diverse subject, bringing in experts from a wide array of areas. Areas like virology, toxicology, parasitology, ecology and pathology. This field of study is influence by so many factors that finding a solution is almost never a cookie cutter situation.

To just give you an understanding on this diverse field, I want to share a definition that I feel best wraps up a definition of what a disease is. Gary Wobeser defines disease in his literature as “any impairment that interferes with or modifies the performance of normal functions, including responses to environmental factors such as nutrition, toxicants, and climate; infectious agents; inherent or congenital defects; or combinations of these factors”(Wobeser, 1994).

I know that is a mouthful, and a bit difficult to understand just with the definition. Let me break it down into an example. This covers any type of disease that a person can think of and for good reasons. If a person thinks of alcoholism, chronic wasting disease, or even avian botulism, they are all diseases because they affect the way the organism lives. This even deals with conditions that we usually do not associate with disease. For instance, if a “snowshoe hare dies as a result of severe intestinal damage caused by parasitic worms, most people would consider this to be an example of disease. If another hare were killed by a great horned owl, we generally would consider this to be an example of predation rather than disease” (Wobeser, 2005). Now, imagine that the hare that was picked off by the owl had the same intestinal worms. Instead of just dying from the parasitism, the hare has to put in extra energy and time into eating more. This means, when all of the other hares are sitting motionless and hiding, waiting for a better time to eat, this parasitized hare has to be out running around getting food. So now, in that extra hour that it had to spend eating, it was then picked off by the owl? Is the death of the hare now contributed to the parasitic worms, or bad luck and predation? You could even extend this definition to cover a deer hit by a car that now has to live its’ life differently because it has a broken leg. This is why his definition includes anything that causes an energetic cost to the organism, as well as creating unnatural behaviors can be linked back to wildlife disease.

It is for this reason, the understanding that there are so many factors you cannot always account for, when trying to manage and understand why wildlife populations react the way they do, that I love this field, and feel it will be around for a long time to come.

One last point that I think is important to remember for all wildlife managers is the idea that “although the thought is unpleasant, it is important to realize that totally natural area’s no longer exist and that all wild animals live in environments that are modified by humans” (Wobeser, 1994). It is for this reason that we must be responsible and do the best jobs we can to protect our remaining populations and natural resources.

Thanks,
-Kyle
UWSP-Wildlife Ecology: Information and Education major, Captive Wildlife minor

Special thanks to Dr. Gary Wobeser and his literature that is the reason I am studying what I am.
Wobeser, Gary A. Essentials of Disease in Wild Animals. Grand Rapids: Blackwell Professional, 2005.

Wobeser, Gary A. Investigation and management of disease in wild animals. New York: Plenum P, 1994.