December Nature Almanac: Yes, Birds Do Yawn!
By Ruth Carol Cushman, with Stephen R. Jones
December 2024
A Great Horned Owl sat in a canyon alcove (an owlcove?) and opened wide its beak. We could see its tongue and red, cavernous mouth. Was it sleepy in the middle of the day? Was this a threat display? A way to let off stress?
A male Great Horned Owl yawning. Photo by Jacob W. Frank, National Park Service. Public Domain.
Never having seen a bird yawn or even heard of such a phenomenon, I was astounded and headed to the internet. As recently as 1989, Laura Erickson (Laura Erickson's For the Birds radio program) wrote “One of the great unanswered questions still facing ornithologists is whether birds yawn.” She quoted a 1930 paper by Oskar Heinroth who called the beak movement “jaw stretching”, independent of breathing and not a true yawn. In the 1930s, most ornithologists agreed that birds did not yawn. Erickson then cited research in the 1960s and 70s on ostriches, cormorants, and Brown Boobies that confirmed that birds do, indeed, yawn. Birds also perform jaw stretching, panting, and other gaping movements that are distinct from yawning.
According to Wikipedia, almost all vertebrates, including birds, reptiles, and even fish yawn.
Almost all vertebrate, including this cougar, yawn. Photo by Tambako the Jaguar. CC-BYND
There’s even a word for the study of yawning--chasmology. You wouldn’t believe the number of Latin words connected to oscitation (medical term for yawning).
So why do we all do it? That does remain a mystery.
Some theories say that yawns clear out carbon dioxide from the lungs or cool the brain. Or, yawns may serve as a threat display. Charles Darwin wrote that baboons yawn to intimidate enemies by displaying large canine teeth. Even guinea pigs yawn when angry or to threaten an enemy. Since Adelie and Emperor Penguins yawn as part of their courtship rituals, we wonder if yawning also aids pair bonding. Recent studies suggest that yawning may help us stay alert or synchronize the mood in herds of animals, such as wolves preparing for a hunt.
Contagious yawning is something we all experience as humans. Back in 1508, Erasmus wrote “One man’s yawning makes another yawn.” Even dogs will yawn back at their humans.
Researchers have found an association between contagious yarning and empathy, but until 2015 they believed it to be limited to mammals.
A pet White-crowned Parrot mid-yawn. Photo by Valyndris, CC BY-SA.
Then four scientists at the State University of New York at Oneonta performed experiments with Budgerigars and found these love birds engaged in contagious yawning. When put in adjacent cages, the birds yawned three times more than when they were alone. In 2015, the results were published in Animal Cognition and later highlighted by Audubon (“Is this the Most Adorable Epidemic Ever” by Shannon Palus, this article includes a video of a budgie yawning).
In the midst of reading about yawning and watching yawns on videos, we couldn’t keep our mouths shut. So, go right ahead, yawn back at the next owl you see!
Other December Nature Events
Common Loons and uncommon loons (Pacific and Red-throated) have been seen at Baseline Reservoir recently (check out the eBird hotspot). Check local bodies of water for loons, swans, grebes, and other waterfowl.
Flocks of Cackling and Canada geese, often numbering in the thousands, form Vs in the sky and forage in fields for grain. Check out those flocks—you might spot a Snow Goose in their midst.
Learn more about our local geese on December 5, 6:30 pm, Lafayette Library, 775 Baseline Rd. Join amazing teen ornithologists, Owen Robertson and Kieran Schnitzspahn, for a fun and very informative introduction to geese in our region and our state.
American Dippers move down from the high county and bob up and down searching for bug bits in city creeks.
Mule deer mating season ends. Bucks start to lose their antlers and join the yearlings in bachelor groups, moving away from the does and fawns.
The Boulder Audubon Christmas Bird Count takes place Sunday, December 15. There will be a compilation dinner, hosted by Bouder County Audubon, after the count. Check the event page on Boulder County Audubon’s website for details and how to participate.
Northern Flicker yawning. Photo: Andy Reago and Chrissy McClarren, CCBY.