RE: Life of Birds (vertical running)

["Michael de Sosa" <ofsosa@uclink4.berkeley.edu>]

Dino G-money wrote:

> What do you mean, "Arboreality is not required"? This running-up-a-tree
> business is arboreality >by definition<. Why would they run up a
> tree if they
> were just going to come right back down again to >avoid< being arboreal??

Because their food sources, nests, water supplies, mates, [etc...etc...]
were on the ground?

The hypothesis suggests that these tree-runners were ground-based animals
that ran up into the trees to escape predators, much like some modern ground
birds. Eventually some must have spent more and more time up there until
they became arboreal, but the first ones would have been mainly cursorial
and would probably go back down once the predator gave up and left.

I used to climb a lot of trees as a child, but did that make me arboreal? My
mom didn't think so... if I didn't come down, I wouldn't get dinner.
Probably similar to the first of these hypothetical animals, come to think
of it.

Or maybe I'm using arboreal the wrong way. I thought arboreal meant you
spent significant portions of your life in trees, not just a few tense
minutes every now and then. Am I misinformed? It wouldn't surprise me if I
just used the wrong word.

Mike D.