Re: 4-CHAMBERED ECTOTHERM

[ornstn@inforamp.net (Ronald Orenstein)]

>Are there any birds that hibernate? Any ectothermic birds?
>

Hibernation is definititely known for the Poor-will (Phalaeonptilus
nuttallii), a nightjar of western North America (body temp. dropping to
18-20 degrees Celsius, or perhaps as low as 10) and probably occurs in other
nightjars as well.  Daily cycles of torpidity (defined in "A Dictionary of
Birds' eds Lack and Campbell as a state of dormancy and lowered body
temperature) are known for some swifts, hummingbirds, nightjars and
mousebirds (Coliidae).  Hummingbirds have a body temp of about 40 during the
day but can drop to near ambient at night (up to 30 degrees difference).
Some manakins (Pipridae) and chickadees can also allow their body
temperatures to fall at night.

There are no bird ectotherms to my knowledge (though I suspect a number of
featherless hatchling birds might be?).  Of course there are no featherless
burrowing adult birds, either!
--
Ronald I. Orenstein                           Phone: (905) 820-7886 (home)
International Wildlife Coalition              Fax/Modem: (905) 569-0116 (home)
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