AUTUMN 2007/VOLUME 21, NUMBER 4
Answers to Your Questions
Why do doves' wings make a whirring sound when they fly?
The sound is actually a whistling—air rapidly moving across or around some sort of constriction in the same manner that sounds are produced when blowing a whistle or flute. It's just that in the dove's case, it's the "whistle" mechanism (the wing) that's moving through the air and not the air moving through the whistle. As for the purpose of this whistling sound, I am not aware of any good explanation.
There are many other species whose wings make whistling noises in flight, and other known purposes for these whistling noises. Some of the whistling sounds are only made under special circumstances, as displays.
One example of this is the Common Nighthawk. Males make sharp display dives and at the bottom arc they pull up sharply and produce a buzzing noise somewhat akin in sound to that of World War II German Stuka dive bombers.
—Wesley Hochachka, associate director, Bird Population Studies
Do owls have eyelashes?
Several bird species, such as ostriches, hornbills, rheas, cuckoos, and some owls in the genus Bubo, which includes the Great Horned Owl, are known to have eyelashes. These eyelashes actually consist of bristles resembling mammalian eyelashes, and possibly serve to protect the eye against dust and other debris. Bristles are simplified feathers that consist only of a stiff, tapered rachis with a few basal barbs. The feathers have both sensory and protective functions.
—Claudia Zan, research assistant, Home Study Course in Bird Biology
When birds eat poisonous snakes, why don't they die from ingesting the snake venom?
The venom works in the bloodstream. As long as the animal has no cuts or lesions in its throat or stomach, it can swallow the venom and digest it without harm.
—Harry Greene, faculty curator of amphibians and reptiles, Cornell University Museum of Vertebrates
We have a pair of crows tearing our windshield wiper blades off our vehicles. We have no explanation for this activity or how to stop it. Can you offer some advice or comments on the behavior?
This is a very odd one. I have now heard about this kind of crow vandalism from nearly a dozen people in a dozen different parts of the country, and I am stumped as to how to explain it. All I can say is that crows are very investigative and curious, and it is possible that these traits have led them to investigate the wipers.
Wipers do not resemble food to me, so I cannot think of a good reason they would attract crows. The wiper blades themselves, though, are exactly the sort of thing that young crows might like to fiddle with: pliant yet resistant; soft enough to dismantle, but tough enough to give a bit of a challenge.
Young crows in their first and second years often "play" with things that are not edible and do not interest older crows. Siblings watch each other too, and often vie for the object in question (be it a feather, a stick, or, perhaps a windshield wiper blade). So, it is possible that one young crow found out about how fun windshield wipers were and then "taught" other family members.
What to do about this? Chase those crows any time you see them around your cars. They will probably keep coming back, and they will probably learn to hate you on sight. Still, it might keep them off. You might also try adding some novelty to the vehicle, such as a tassle hanging from the radio antenna, or change where you park the car. Crows do not like new things in an area where humans hang out.
If none of this works, try getting a car cover like people with expensive antique cars use. It might be a pain, but it will probably be less expensive than weekly windshield wiper replacements. For more crow FAQs, visit www.birds.cornell.edu/crows.
—Kevin McGowan, research associate and resident crow expert
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