(Wide load, full view please
I wish you a merry Eastermas! We're at the brink of a white Easter... temperatures are still close to freezing, it was snowing the last two days, but today it's all melting again.
Anyhow, here's a photo taken at Tierpark Sababurg two weeks ago of one of the wolves scent rolling on some carcass.
In "Wolves - Behavior, Ecology and Conservation" (MECH, BOITANI, 2003) Fred H. Harrington describes this behavior as such: "This ritualized behavior involves lowering the head and shoulders onto the substrate, followed by rubbing the chin, cheeks, neck, shoulders, and back on the odorous substance. Natural stimuli for scent rolling, such as rotten carcasses, typically have very strong odors that humans find offensive."
This behavior can be elicited by a variety of strong odors, just as perfume sprayed onto the ground.
It is hard to explain why wolves (and dogs in general) scent roll. Erik Zimen believed it was done to conceal one's own scent with something more pungent. Fox thought it could make oneself more attractive by applying a novel odor, or just familiarizing with novel odors or changes in odors. Some believe it might be a way to bring back a message like "hey, I found a fresh carcass over there" back to the pack.
Whatever the real reason is, they really seem to enjoy the process