Kevin Li wrote:

>Thanks for the information, although it begs more questions and rampant
>speculation. What do choughs eat? What are they doing up there that they
>can't do at a lower elevation?

I presume choughs are omnivorous like most of their relatives, in which
case they probably eat most everything up there, which includes carcasses
of (and perhaps occasional live) bird and mammal species that at or near
that altitude, garbage from climbers (hopefully not much), and wind-blown
INSECTS from lower altitudes that have fallen on the snow and are too cold
to take flight again. The volume of insects is phenomenal in some places.
John S. Edwards (UW Entomologist) has measured this in Alaska, Australia,
and Washington, and wrote a nice review in 1987 on the topic (Arthropods of
alpine aeolian ecosystems, in Annual Review of Entomology, volume 32,
pp.163-179.) Such insects form a major food source and are at the base of
the food web for alpine bird species throughout the world, including our
American Pipits and Rosy-Finches.

What can they do up there that they can't do lower? I'd prefer to word it,
What can they do down here that they can't do up there?! From an
ecological point of view, they have less competition up there (an
advantage). That perhaps is needed to offset the added energy demands of a
cold environment. But, all in all, it balances out and they do VERY well.
I'm jealous; I'd just as soon be up with them. And think of the view!


Richard E. Johnson
Curator, Conner Muesum
Washington State University
Pullman, WA 99164-4236