Re: Hadrosaur nesting strategy...(was Re: The Life of Birds- Pa

["Larry Febo" <larryf@capital.net>]

----- Original Message -----
From: <B.Dol@skn.sc.philips.com>
To: <larryf@capital.net>
Cc: <dinosaur@usc.edu>
Sent: Wednesday, July 28, 1999 10:19 AM
Subject: Re: Hadrosaur nesting strategy...(was Re: The Life of Birds- Pa


> So wouldn't it be more logical to assume that the reasons for
> migration are not avoiding predators, because in another area there
> will always be other predators...maybe not that many or directly
> threatening, but they could in time evolve that way.
> Just a thought.
>

I don`t know for sure. The avoidance of predation upon the young I had once
read,...somewhere (can`t remember where). Sounded like a good, logical
reason  to me. It`s amazing how much evolution revolves around raising up a
new brood. That`s the definition of biological fitness,...the number of
offspring that survive to reproduce on their own.

It was suggested to me (offlist) that more abundance of food was the reason
for bird migration. I thought food was always much more abundant in the
tropics, and therefore the ability to brood in a colder enviorn as
protection from cold-blooded predators would be the determining factor in
bird migration. Then again, not all birds migrate. How do the tropical
variety cope (with predators)?