Re: Tail feathers

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

On Sun, 21 Jun 1998, James R. Cunningham wrote:

> (Pigeons) can climb at about 490 feet per minute (over 8 fps
> vertical) for short bursts.
>       Jim

Jim, I wonder if you would comment on the following idea I haven't seen
before. The skill you are talking about applies not only to herbivores
but also to carnivorous birds.  For example, Caracara and Chimango birds
of prey wait patiently near a rhea and its hatchlings.  If one strays
(this can happen especially in heavy weather) from the parent they are
immediately snatched up.  Now, the rhea is an extremely aggressive parent
and would kill the birds of prey if it could get near them.  But it can't
because (I'm guessing) the predators can make a speedy getaway.  So, the
evolution of this tail apparatus was likely a new problem for non-avian
dinosaur hatchlings sometime in the latter half of the Cretaceous.