American White Pelicans are known to do some pretty strange things with their pouch – one of them is pouch stretching (I’ve been unable to find an official term for the behavior).
A four year old image – I no longer have the original file so can’t access exif data
They pull their head back and force their very flexible pouch down over their neck and upper chest in a process that looks, well.. bizarre. I don’t think this behavior is particularly unusual as I’ve seen and photographed it several times. According to Birds of North America Online the function of this display is “uncertain”.
Canon 7D, 1/5000, f/6.3, ISO 500
However, these birds are also fully capable of pulling the bottom of their pouch up above the level of the lower mandibles without having to pull the pouch down over their neck. I don’t fully understand how they’re able to do this since the pouch itself is non-muscular. Internet research on the subject has been unproductive. I assume there must be some form of bony or cartilaginous rod that extends from the throat area down the middle of the bottom of the pouch about half way to the tip of the bill. With muscular control of the base of that extension in the throat area they would be able to raise the bottom of the pouch above “horizontal”.
I’ve seen them do it twice – the first time without a camera while the bird was perched. But the second time, a couple of weeks ago, it was done in flight which I suspect might be quite unusual as it’s something I’ve never seen before and I have been unable to find any photos of the behavior (in flight) with an internet search.
Nothing mind-boggling here but I thought it to be interesting enough for a brief post.
Ron
I was down in Galveston this morning and saw that brown pelicans do this behavior as well. The one I captured doing it had been grooming himself.