Predator (Wolf) and Scavenger (Raven) working together

"Apart from their own pack, wolves interact with ravens more than any other animal. The ravens are the most obvious beneficiary from the wolfraven relationship. Studies have found that 100% of wolf kills are visited by ravens and nearly 2/3 of the carcass is consumed by the raven. The official term for their relationship is predator-scavenger interspecific kleptoparasitism, or, in English, a relationship between two different species where the scavenger benefits off the predator by stealing a portion of their food. The ravens stay close, recognize a wolf’s hunting cry, and follow the hunt from above. Ravens cannot open a carcass on their own, so without the wolves’ help, the eyes are the only edible part of the carcass for a raven. In this instance, the wolf is the predator being taken advantage of by the raven. However, wolf and raven behavior doesn’t perfectly fit the kleptoparasitism model. After a kill, wolves will only eat their preferred cuts of the meat and ignore the ravens and other scavengers pecking at the opened carcass by their side. If this were truly a competitive or parasitic relationship, the wolves would protect their meal like they often do against bears.

Even more counter intuitive, ravens are scared or “shy” of large carcasses and won’t feed on them unless a wolf is nearby. In addition. though wolves were gone from YNP for 70 years, ravens preferentially follow wolves significantly over coyotes or elk. If ravens were solely opportunistic, then a raven would choose a carcass without a wolf and would be equally likely to follow coyotes. These odd behaviors hint at an innate, ancient, and evolved mutualistic, not parasitic, relationship between wolves and ravens.

Wolves obviously don’t mind ravens and have evolved with ravens, so what are they wolves getting out of their relationship? When wolves and ravens are preoccupied with feeding, the ravens remain extremely alert and will call out if danger is near. The ravens act as another set of eyes and ears, not only at a carcass, but in the sky. Ravens have on multiple occasions been observed locating, harassing, and yelling at injured elk to draw the attention of wolves. Furthermore, there are numerous wolf-raven anecdotes that illustrate their special relationship. For example, a biologist studying wolves wrote about an interaction he saw of a raven pecking at the tail of a wolf and jumping away when the annoyed wolf snapped back in retaliation. A wildlife photographer saw a nearby wolf open up a bear carcass for a yelling raven who found the body. One wolf watcher noticed that ravens hang around wolf dens and play with three-week-old wolf cubs. Both ravens and wolves have the social abilities to form bonds between individual ravens and individual wolves. I have my own anecdote. Soon after spotting the wolves, I saw a raven. At first it was circling close above, but then it swooped down towards a wolf, taunting it. The wolf, in turn, jumped up and snapped its teeth at a safe distance from the raven. They repeated this dance a couple times. What at first looked like an aggressive interaction was actually two friends, playing. Watching the wolf and raven’s unique relationship play out in the Lamar Valley is a moment I will never forget."

Original

Erdas, Caterina (2020) "Wolves and Ravens: Defining a unique relationship," Osmosis Magazine: Vol. 2020: Iss. 1 , Article 6.

References 

1. Blakeslee, Nate. (2018). American Wolf: A True Story of Survival and Obsession in the West. New York: Broadway Books. 

2. Middleton, A. (2014). Is the Wolf a Real American Hero? New York Times. https:// www.nytimes.com/2014/03/10/opinion/is-the -wolf-a-real-american-hero.html 

3. Yellowstone Wolf Project Annual Report. (2018). Yellowstone Center for Resources, The National Parks Service, Department of Interior. https://www.nps.gov/yell/learn/ nature/upload/2018-Wolf-Report_web-2.pdf 

4. Ballard, B. W., L.N., D.W. (2003). Wolf interactions with non-prey. Wolves: Behavior, Ecology, and Conservation, 325, 259-271 

5. Stahler, D., Heinrich, B., Smith, D. (2002). Common ravens, Corvus corax, preferentially associate with grey wolves, Canis lupus, as a foraging strategy in winter. Animal Behaviour, 64(2), 283–290. 

6. Heinrich, B. (1999). Mind of the raven: an investigation into the mind of the raven. New York: Cliff Street Books