Re: 4-CHAMBERED ECTOTHERM

[Dinogeorge@aol.com]

In a message dated 96-01-26 21:44:41 EST, pharrinj@PLU.edu (Nicholas J.
Pharris) writes:

>> _Heterocephalus glaber_, the naked mole rat, was shown in 1993 to be a
>truly
>> *ectothermic* mammal. It too has a 4-chambered heart. 
>> 
>
>And it also evolved from endothermic ancestors.  

This brings up the point that mammalian endothermy isn't quite as complete as
that of birds. During hibernation, mammals effectively become ectotherms. I
can see how a burrowing mammal might evolve ectothermy as a modification to
its hibernation physiology.

I could live with croc ectothermy being secondarily derived from some similar
kind of incomplete thecodontian endothermy.

Are there any birds that hibernate? Any ectothermic birds?