Regarding Hugh Kingery's description of 50 Cliff Swallows perched on the ground on a warm day.
This phenomenon is called "sunbathing," and I have included some references to descriptions, photos and videotape of birds sunbathing. There is speculation that this behavior may have to do with getting feathers back into place (a preening equivalent) or bringing parasites up to the surface where they can be removed. It probably does not have to do with thermoregulation or with vitamin D absorption. Video: http://www.arkive.org/barn-swallow/hirundo-rustica/video-09c.html Blackbirds and other thrushes often *sunbathe*, laid down and with wings outstretched. The sun is thought to straighten the birds feathers and help the preen oil to spread through the feathers. Some ornithologists have suggested that it may also draw parasites to the surface where the bird can remove them or that the ultraviolet light in the sunlight converts chemicals in the preen oil into Vitamin D. However, one could be forgiven for thinking that they simply enjoy it. The RSPB said it receives up to 100 calls during hot spells, from people concerned at seeing birds lying with their feathers and wings exposed to the sun. But they have said it is nothing to be worried about, the animals are simply sunbathing. Studies from the University of New Mexico suggest that birds sun themselves after heavy rain, which can cause them to suddenly lose their feathers, beacause it helps to soothe their skin. It is thought the sun helps straightens the birds' feathers and helps the preen oil to spread through. Gemma Rogers from the RSPB said: "People become concerned about these birds, because they seem to have a glazed expression in their eyes, because they are not focusing on anything, because they are entranced by the sun." "They don't let themselves overheat at all. The feathers would protect them as well, so I don't think they need the factor 30." The biggest concern, she said, is that predators will attack while the birds enjoy a peaceful moment in the sun. "They are on the ground, they have their heads up, their legs wide open, but usually they fly away once a predator approaches. Their hearing is very acute as well, so even if they aren't focusing they will hear something coming." While blackbirds are the most commonly spotted sunbathers, pigeons and sparrows enjoy the sun also. Sparrows also appear to enjoy going to the beach as much as humans, according to Miss Rogers. "Sparrows often find a hot sandy area as well to have a sand or dust bath. That looks really strange. They bed themselves down and get in there and cover their feathers." But it is thought the dust soaks up excess preening oil and removes dry skin and mites. While they may enjoy the heat however, the RSPB called on people to put water out to stop birds overheating and becoming dehydrated. "We have had a lot of water for them this summer, but during hot spells they do need to cool down," Miss Rogers added. Joe Roller,Denver -- You received this message because you are subscribed to the Google Groups "Colorado Birds" group. To post to this group, send email to cobirds@googlegroups.com. To unsubscribe from this group, send email to cobirds+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/cobirds?hl=en.
