Today John Avise presents one of his “bird theme” posts. The title is below, the captions and IDs are John’s, and you can click on the photos to enlarge them:
Avian Yawns (Open-Wide)
Strangely, I won’t be disappointed if some readers yawn their way through this set of photos (because yawning can be contagious). I’ve noticed that many vertebrate animals, ranging from mammals to fish, occasionally yawn, perhaps merely to stretch jaw muscles or maybe as an indication of sleepiness. Except when singing or eating, birds normally keep their upper and lower mandibles shut. But this batch of photos shows several birds caught with bills wide open in what might be interpreted as a yawn (or in some cases a yawn stifled). Can you get through these pictures without wanting to yawn too?
California Gull (Larus californicus):
Western Gull (Larus occidentalis):
Another Western Gull:
Ring-billed Gull (Larus delawarensis):
Heermann’s Gull (Larus pipixcan):
Forster’s Tern (Sterna forsteri):
Another Forster’s Tern:
Sandwich Tern (Sterna sandvicensis):
Caspian Tern (Sterna caspia):
Limpkin (Aramus guarauna):
Clark’s Grebe (Aechmophorus clarkii):
Ferruginous Hawk (Buteo regalis):
Anna’s Hummingbird (Calypte anna):
Ring-necked Duck (Aythya collaris):
White Ibis (Eudocimus albus):
Roseate Spoonbill (Ajaia ajaja):
African Spoonbill (Platalea alba):
Ha! You’re right – I had to yawn before I got past the third photo. Great pix. Thanks for sharing.
Interesting and good “gotchas”. I like “themed” posts.
It’s the tongues! Never thought much about there being that much different or how they might use them.
I yawned twice! Contagion or the power of suggestion?
Very cool photos John. You must have a vast library of bird photos!
The clarke’s grebe yawn looks distinctly odd – as if the upper mandible is the articulating one!
A bird can flex both upper and lower jaws, although maybe some are more obvious about it. Its a trait left over from their Dino ancestors, interestingly.
The term for having an upper jaw that can also pivot is a great one – Rhynchokinesis.
I wonder how to preserve the rhamphotheca when I get a bird skull & allow nature to deflesh it…? I must look that up!
No yawning, but definite grin. I couldn’t help but think of this as a collection of avian opera singers.
I was going to suggest the all gull choir with others waiting to take their tern. Then thought better of it 😉
I like it!
What an amazing photo collection you must have to show a collection on just this one topic, John! Very interesting.
My thoughts exactly! (Didn’t yawn but hiccupped a few times. 🙂 )
I didn’t yawn because many of the birds looked as if they were screaming or laughing at jokes.
OK NOW I’m yawning, but it is 12:30.
Great pics by the way. Thank you.
And aren’t spoonbills evolution’s little punchlines? Like hammerhead sharks or that poor pulsating parasite infested snail we saw the other day here, the psychedelic one. Still dream about that sad guy.
D.A.
NYC
https://whyevolutionistrue.com/2020/06/10/photos-of-readers-93/
Why can’t you durn biologists figger out why critters yawn?
This is highly conserved behavior, so it must be serving a very important purpose. There are lots of hypotheses, but no settled answer.