By: Michael Allen Bryden
The interaction between individuals of different species has been recorded throughout natural history. Mutualism, more specifically, occurs when two such species' interaction results in positive and beneficial effects for both animals. There are many famous examples of this mutualistic relationship, including the Honeyguide leading the Honey Badger of Africa to its next shared meal as well as the Oxpecker receiving a fresh spread of insects when cleaning Zebras and Rhinos. Recently, an interesting new wild alliance was discovered between the Common raven (Corvus corax) and the Gray wolf (Canis lupus) in Yellowstone National Park.
Brad Bulin, Senior Naturalist at Yellowstone National Park, states that “ravens have important ties to wolves''. Commonly known as “wolf birds”, ravens use Gray wolves to aid in finding food, scavenging the meat that is left as a by-product of a wolf pack’s hunt. Since the wolves' reintroduction into the park, they have provided a year-round supply of food not only to ravens but to other species as well including bears, eagles, and magpies. This leftover meat is referred to as "carrion" and it is food that might not otherwise be available to other animals, especially those that do not make their own kills. In the case of wolves and ravens, ravens will often be on site while the kill is actually happening, with up to 135 individual ravens having been documented at a single kill site at once. Ravens are very intelligent birds and are highly regarded for their social and vocalization skills. It is thought that wolves may be able to interpret the calls made by ravens indicating the location of their next meal, formalizing in the process this incredible mutualistic relationship.
This mutualistic behaviour has led to more frequent interaction between the two species, in some cases surpassing what would be expected. For instance, ravens have been seen interacting with wolves beyond kill sites, most commonly with young wolf pups. These birds have been observed grabbing sticks and playing tug-o-war with the puppies, as well as flying just overhead while the pups jump at them. Some ravens have even been seen daringly pinching at adult wolves’ tails to instigate a reaction. Some scientists hypothesize that individual wolves within the pack may have developed special bonds with individual ravens. This type of connection between the two species, one an apex predator and the other a scavenger, suggests that it transcends one based strictly out of necessity for survival to perhaps that of friendship!
Biologists John Vucetich and Rolf Peterson of Michigan Technological University uncovered very similar results over a 50-year study in Isle Royale National Park. On this island in Lake Superior, ravens were found near wolf kill sites 99.7% of the time in the winter months. These birds were observed devouring a large portion of the wolves' meal themselves almost immediately after it was killed. As to why the wolves did not chase off the ravens baffled the biologists, which eventually led them to believe there may be a special relationship between the two species.
This unique friendship is still newly discovered, and maybe in due time scientists will learn more about their interconnection with each other. As of now the reasoning behind these interactions is still a mystery.
Axelson, G. (2012, April 15). Dinner Guests: How Wolves And Ravens Coexist At Kills. Retrieved from AllAboutBirds: https://www.allaboutbirds.org/news/dinner-guests-how-wolves-and-ravens-coexist-at-kills/
Bulin, B. (2020, March 10). Naturalist Notes: Wolves and Ravens. Retrieved from Yellowstone Forever Organization : https://www.yellowstone.org/naturalist-notes-wolves-and-ravens/
New England Complex Systems Institute. (n.d.). Mutualistic Relationships. Retrieved from necsi: https://necsi.edu/mutualistic-relationships