> Why do coots bob their heads when they swim? Does it make them more
> efficient paddlers somehow?

It's because of the spring inside their neck - your lab needs a
jack-in-the-box.

> Do swifts *really* sleep on the wing or is that just a rumor?

Only if they're sleeping on their sides, in which case it might be
either wing, not THE wing.

> When a hummingbird goes into torpor for the night, does it try to build a
> little nest or find an insulated crevice, to save as much heat as possible?

A calorie saved is a calorie earned.

> Why does a nighthawk have combs on its claws?

You expect them to comb with their tails?

> Thanks --

No problem!

OK, a little more seriously, I can help a teensy bit with one question:

> When a hummingbird goes into torpor for the night, does it try to build a
> little nest or find an insulated crevice, to save as much heat as possible?

They don't build little nests ("nestlets"?).

End of teensy help.

I know that some, at least, build their nests on a branch that has
another branch just overhead and that this is thought to help the
brooding bird conserve heat. They may seek similar situations when
they enter cold torpor, but I don't know.

- Don Baccus, Portland OR <donb at rational.com>