Re: Point of brooding is...

[John Bois <jbois@umd5.umd.edu>]

On Sat, 6 Mar 1999, Ronald Orenstein wrote:

> This is not, as I understand, what Tom Hopp is talking about.  

I am not arguing for or against his position.  Remiges may or may not have
evolved to enhance the retention of heat which, as you say, is delivered
by a sometimes naked brood patch.  But feathers are not necessary for
brooding--except in extreme environments, eg., Antarctica.  And, inasmuch
as there may be a cost associated with their possession--enrgy to grow
them, parasites living in them, excess baggage for speedy running, one
would think there would be easier ways in equable climates to maintain a
constant microenvironment.

What I was arguing was your statement that if they were advantageous to
brooding, then other non-flying egglaying animals would grow them.  I
don't think you can say that unless the animals in question are warm
blooded, since the presumed advantage would be to retain heat.  And with
few exceptions, birds are it.  I was amused at the prospect of feathered
turtles.  And so I asked which animals you meant?