Watched and photographed this juvenile White Ibis feeding for about an hour. All of a sudden he expelled this "pellet." Magnified, it appears to be a ball of crustations that the bird's system was unable to digest so it was expelled. I have never seen this before but assume it is something all of these birds experience. Would love some feedback about this behavior.
Well a birder friend of mine explained today that this is called a "bollis" which is similar to an owl pellet. Many birds that swallow prey whole do this b/c they have little or no crop in which to grind food the way raptors and warblers do, so they digest what they can and puke the rest. Apparently, it is also rarely seen in action, so I am pretty pleased to have witnessed this...although a better HA would have been awesome!
I did a Google search on bollis shorebirds and didn't find anything but if you look up pellets shorebirds there is lots of info. I am not saying your friend is wrong just that I have never heard of this, would he/she have any references. Keep in mind also I am not any kind of authority on this.
Thank You
Bill
Added
I did find that in falconry it is called casting.
Neat behaviour Marina, thanks for posting. I got lucky with a Yellowlegs chucking a pellet a while ago (and I got the same head angle issue too!! See here:
The word is actually "bolus" and is usually used to refer to a "food bolus" or a roundish lump of any food that is either fed to chicks from parents, to female from the male or is passing through the digestive system of the bird. The term derives from the word for a ball and I suppose could be used to refer to a pellet such as this. However, since we have the word pellet, it's probably better just to stick with that.
Thank you all for the information. I also learned that when the "bolus" or "pellet" is ejected that it is called "casting." Learn something new every day. Old or new, I am always happy to learn new words, terms and information about most anything.
John, I noticed the saliva/spit too. I WISH so much that I had been sitting at a better angle but my friend was in that spot and of course, who knew this behavior was going to happen. Just glad to have witnessed it and been able to capture it.
Behavior: White Ibis (juv) Up Chuck
Posting Permissions
Reply With Quote