Wildlife Wednesday — Mutualism

By Andy Ames

Recently we looked at the symbiotic relationship between skunks and foxes. Using their combined talents, both were more successful hunting when together than when hunting independently. This is a form of “facultative mutualism” where both species benefit from each other even though each are capable of surviving on their own.

Pictured here is another example of “facultative mutualism” you may see in the Estes Valley - the pairing of a Black-billed magpie and a Mule deer (or often an elk). Sometimes the deer may look annoyed, other times relaxed, as the magpie hops around from tail to ears looking for ticks. In this case both benefit - the magpie gets a meal and the deer gets a back massage and rid of the tick. But there are other symbiotic relationships going on here as well. The tick itself has either a parasitism (one benefits while the other is harmed) or a commensalism (one benefits while the other not harmed or helped) relationship with the deer, depending on if the tick passes on a disease to the deer or not. Going further, the tick may have a symbiotic relationship with various bacterium, viruses, or fungi that it has picked up from interactions with previous hosts.

But wait, there’s more! The most important relationship here is one you cannot see. Deer (and other ruminants such as elk, moose, and sheep) host a variety of microbes in their digestive system. These microbes feed on and break down the cellulose in the plant material the deer eat. Both are dependent on eachother and could not survive without the other, a form of symbiosis called “obligate mutualism.”

All this goes to show that we are all interconnected and that there is much more than meets the eye.