River Otter Vocalizations: the Purr
There have been only two studies of North American river otter vocalizations, both mentioning 12 different calls: the whine, chirp, grunt, blow, chatter, creek, squeak, scream, hiss, swish, hiccup, and whistle. You can see a description of each one in the studies listed in “Sources” below. I was struck by the fact that neither the name nor description of any of those sounds matches what I hear most commonly from wild otters playing, scent marking, and grooming at latrines, as recorded by my trail cameras.
That common sound is an almost continuous, pulsed, low pitched vocalization that I think of as a buzzy grunt. I’ve also witnessed its use in person by otters swimming together. However, I have never heard it used by lone otters. To hear this sound – the buzzy grunt not mentioned in the two studies – watch the video below with the volume turned up. You will also hear some chirps, and maybe a couple of other distinct but less common otter sounds.
I was curious as to why nothing matching the description of that buzzy sound was mentioned in either study of river otter vocalizations, so I contacted the author of one of them. Naturalist Sarah Walkley said that the sound to which I was referring is usually called a chuckle, coo, hum, or purr and considered to be an “affiliative / all is well” call. Ah. It means “here I am with my friends, feeling good”. A sound of contentment. That fits perfectly with my own observations, and “purr”, to choose from among Walkley’s labels, is a good word for it. It sounds a little like a cat purring, and a bit like a ferret “dooking” (google that one).
Walkley explained that she did not mention purring in her paper because it was used very rarely by her study subjects, two groups of captive otters. I suspect it was not mentioned in the other study (also involving only captive otters) for the same reason, though I did not contact the author to ask.
So why am I making an issue about this purr? One reason is that once you recognize it, that sound might cue you in to the presence of otters when you’re out hiking near a water body. It can help you find otters. The other reason is that it may be telling – in a sad way – that this common sound of contentment was rarely heard in the captive otters studied.
So often we humans assume that because zoo animals are well fed and safe, they must be happy. Not necessarily so. For all we know, many of them could be bored out of their minds. Perhaps they long for freedom, the chance to explore, the challenge of foraging for their own food, of finding their own mates, of establishing and defending a territory. As fairly large and intelligent creatures, otters need space and stimulation, perhaps more than can be provided in zoos.
We don’t know. I do know even as a child I never enjoyed zoos. They look like prisons to me.
Related Posts
Sources
- Almonte, C. “Classification of Captive North American River Otters (Lontra canadensis) Vocal Repertoires: Individual Variations, and Age Class Comparisons.” Animal Behavior and Cognition. 1 (2014): 502-517.
- Walkley, S. N. “Vocalizations of North American River Otters (Lontra canadensis) in Two Human Care Populations.” Masters Thesis, University of Southern Mississippi, 2018.
Thank you for this post and for the digging into research you did on otter vocalizations Janet! To me, the purr sounds remind me of buzzing flies. And, I’m with you on zoos. I can’t bear them, never have.
Yeah it does sound more like a buzz than a purr, but purr captures the idea that it’s a sign of contentment so I sort of like that label, too. Zoos suck. I know that a lot of good conservation work has been done at zoos, but it’s hard to deny that many individuals suffer in them. We’ve all seen the repetitive movements (as Anne Marie mentioned below) and there are probably much more subtle signs of discontent, like the lack of purring in captive otters, that we don’t usually pick up on.
I feel the same about zoos. I remember taking my nephew as nd niece and watching a polar bear walki g in circles in a small enclosure- never went back. On a similar note, I feel I owe it to our dogs to find places where they can run free, off leash , safely. Their exuberance says it all.
Oh, yes, captive polar bears! I have a similar haunting memory about a polar bear swimming in circles in his tank. Horribly disturbing. These are things that keep me awake at night. I don’t have a dog but feel strongly as you do that they should have space to run freely. How horrible it must be to be restrained on a leash for every moment outside the house.
I could watch otters play for hours. Great post!
Thanks! I’m glad you enjoyed it.
All written here about our animal friends running freely …. true …. But we need to run freely too. Growing up in the 50s I ran about in fields and woods of the Genessee Valley unconstrained. After working in many place (Germany offered the most freedom to wander) I retired in Western New York in 2007 and have been fortunate to gain complete access to several large properties. Many are not at fortunate.
So true. We humans need to run freely as well, and kids don’t do that much anymore. But with the trappings of electronic entertainment, fears of lyme disease, and the pressures to pile organized activities in kids’ schedules, I don’t know if there’s much hope for that.
After watching and listening to the video I’m coming back as a WILD otter.
Good point! I’m going to similarly amend my reincarnation plans!
I just got some great video of a couple of otter playing in our river and couldn’t find a good description of the sound I heard until I read this. I described it as more of a chuffing/purr sound, noted as they were checking us out. They certainly didn’t seem worried about us, mostly curious. They’re my favorite animals, and I love spotting them!!
How cool that you got to see/hear them in person! I have actually located otters by listening for that sound. It seems to be a really common sound they make when 2 or more are together. Such complex, interesting, and beautiful creatures.
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I spent about 20 minutes photographing a solitary river otter yesterday (January 17 2021) who spent its time either grooming on the icy edge of the open water, or swimming around emitting a rhythmic and continuous series of purr/grunts. Sounded like an expression of contentment. You can see the otter here: https://www.inaturalist.org/observations/68197738
Beautiful photo, and must have been a great experience. So interesting that it was vocal with no other otter in sight. I’ve continued to place cameras at otter latrines and still haven’t gotten a lone otter vocalizing.
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Hi Janet,
Can you put me on your blog mailing list please?
Done!