Spring and summer are tick season for elk and other wildlife in Rocky Mountain National Park. It is also a season when black-billed magpies (Pica pica) are especially numerous riding around on elk (Cervus elaphus canadensis) and looking for all the world like jockeys. In fact, they are fulfilling their role as scavengers by searching for and eating ticks and other external parasites off the elk. The elk seem to appreciate the service, and having these blood suckers removed, especially before they attach, definitely contributes to the elk's health. Some of the diseases ticks carry include tick paralysis, Colorado tick fever, Rocky Mountain spotted fever, Q fever, and tularemia.
The role of magpies in removing ticks from elk was noticed at least as early as 1931 by park rangers. Edmund G. Rogers, author of the March Superintendent's Monthly Report for 1931observed of the elk "A few of the animals have rather ragged coats and a few are evidently infested with ticks...a group of magpies was staying close to the herd." He went on to say "often one of the birds would alight on an elk, and appeared to be searching and occasionally finding something...many of the elks showed no concern at these scavengers hopping around on their bodies." He concluded "the magpies were picking ticks of the elk."
While magpies are serving an important role in the ecosystem by removing parasites from elk, they look comical sitting on the elk's heads and backs or walking down their sides. Keep an eye out during your next visit to Rocky Mountain National Park - you might see an elk jockey or two! Also, if you are bitten by a tick, monitor your health carefully over the next several days, and see a doctor if you become unexpectedly ill. Unfortunately, magpies have not yet learned to remove ticks from humans!