Every other Friday, the Outside/In team answers a listener question about the natural world. This week's question comes from Dustin in Anchorage, Alaska after his dog found a dead whale rotting on the tidal flats near town.
“Why do dogs love to roll in things so much? I understand that they have a really strong sense of smell and why they're interested in sniffing or maybe eating things that we would find gross, but what is it about rolling in things and getting that in their coat that they like so much?
Host Nate Hegyi plugged his nose and grabbed some soap to find the answer.
Nate Hegyi: This is a very familiar problem for me. My dog has the uncanny ability to find every dead fish on the beach and roll in it. It happens so much these days that it is very normal for me to take a shower with him after a walk. To my nose… it is disgusting… but to him?
Chris Schell: Your dog is probably doing that because they really enjoy it. It’s just play behavior.
Nate Hegyi: Chris Schell is an urban ecologist and assistant professor at the University of California - Berkeley.
Chris Schell: The animals are getting a kick out of all of the novel scents, and because their olfaction is dozens of times more sensitive than ours they get a lot of exhilaration and joy from just rolling around in that stuff.
Nate Hegyi: But dogs aren’t just gluttons for pleasure. One kind of obvious reason they’re attracted to dead stuff is they like to eat dead stuff. And just like their canid cousins, wolves and coyotes, dogs are pack animals. So getting back to the den and smelling like rotting fish says something.
Chris Schell: It allows them to communicate with others in their tribe that, "Hey, there's some food over here. Look! I smell like it!"
Nate Hegyi: Kind of like how we humans will post a photo of a pretty sunset or a super bloom on Instagram. For dogs… it’s more like #deadsalmon or #rottingwhale. Now, sometimes dogs roll in dead stuff not because they want to smell like it… but because they want it to smell like them. This is known as scent-marking. A way to tell other dogs that this decaying chunk of fur and meat is mine. I got dibs. Stay away! Chris says canines aren’t the only animals getting up close and personal with the dead. Elephants, for example, will often rub their trunks on other dead elephants.
Chris Schell: They may partly be doing that to assimilate the scents and getting olfactory cues and stimuli from the dead organism to then honor that organism. Which also comes in the form of animal culture, right? Many cultures in animal societies mourn their dead.
Nate Hegyi: I would like to think that’s what one of my dogs, Gilly, was doing when she literally rolled in… the skeleton of a dead dog. That image is seared into my memory. Anyhoo, the list of why animals roll in dead stuff continues.
Chris Schell: So if you smell like something dead, there may be animals that don't want to eat you.
Nate Hegyi: Think "Walking Dead," right? Where the heroes cover themselves in blood and guts so they don’t get eaten by zombies. Finally, there are crows and ravens. We talked about this in a recent episode of Outside/In, but…
Chris Schell: Crows may not necessarily roll around in the dead material of one of their compatriots, but they certainly will circle around their dead compatriot to investigate what may have happened to that animal.
Nate Hegyi: They essentially act as murder investigators. But that isn’t the only reason crows will get cozy with the dead. Very occasionally, crows have been observed having sex with the dead. This tends to happen during mating season. So scientists think maybe their hormones are going wild and they just… pick the wrong mate. So Dustin, at least be happy your dog isn’t doing that to a rotting whale
If you’d like to submit a question to the Outside/In team, you can record it as a voice memo on your smartphone and send it to outsidein@nhpr.org. You can also leave a message on our hotline, 1-844-GO-OTTER.
