Ruffed Grouse Preening
Most birds, the ruffed grouse among them, have a preening gland, also called the uropygial gland, on the rump at the base of the tail. It secretes a rich oil of waxes, fatty acids, fat, and water that is used to clean and lubricate the feathers. The bird rubs or squeezes the gland with its beak to pick up some of the waxy substance, then applies it by nibbling or stroking each feather from base to tip.
The video below, from a close focus trail camera stationed at a drumming log in Massachusetts, beautifully captured a ruffed grouse preening. Watch how the bird nibbles at the gland before tending to its feathers, and note how it strokes the length of its tail feathers with its beak. About halfway through the video, you see the bird rub its head on the gland, thus cleaning the head feathers.
At a couple of points in the video you get a pretty good view of the gland, a nipple-like structure with a small tuft of dark feathers at the tip. To provide a clearer view, I grabbed a frame from the video and zoomed in on the gland.
The exact benefit of preening may depend on the species of bird and remains the subject of debate among ornithologists. Possible functions include control of harmful microorganisms and parasites, maintenance of insulating and water repelling properties of feathers, maintenance of proper feather alignment for aerodynamic flight, preservation of healthy feather appearance for mate attraction, and chemical communication. It has even been suggested that preen oil can penetrate egg shells to provide odor information to embryos.
For more on the ruffed grouse, see Ruffed Grouse Drumming and Little Drummer Bird. Read more about the uropygial gland.
Excellent video and still — what camera are those from?
Thanks. It’s the Bushnell NatureView HD Live View, which comes with 2 close focus lenses for subjects about 18-24 inches from the camera. Not bad for an off the shelf trail camera.
Beauty…function…mystery
Nature knows the way.
Indeed. Thanks for stopping by, Charlie.
Janet, yet another great video and posting. These always make my day! Thank you, thank you, thank you!
Glad you enjoyed it, Lori!
Amazing video. Charlie said it perfectly. Something one would never see unless had time to spend sitting for hours patiently and quietly while trying not to disturb the subject with one false move.Another example of video cams unraveling mysteries.
Yes, it really is amazing what you can capture with these cameras. Before this, I’d never seen the preen gland of a wild bird. I realized what this was only because a veterinarian once pointed out the preen gland to me on one of my chickens.
Fascinating. I have often observed birds do this movement. Wild turkeys seem to have preening sessions in front of the trail camera. Now I know what they are actually doing. Thank you.
You’re welcome – I’m glad you found it useful. Thanks for commenting!