Carcassman,

I'm not denying the possibility, but since it runs counter to general ecological principles, the explanation, or hypothetical explanation, ought to accompany the statements about this prey selectivity. Absent a meaningful context, it comes at me like the advocates don't think anyone else studied biology and ecology.

Ecological relationships make sense if we study them. The Yellowstone wolf example is a good one. Wolves that prefer elk made sense because the YNP elk herd was too large for its range, and a large % of the population consisted of cows beyond calving age. Hence the population had reached a level of low productivity. This doesn't mean those wolves won't, and haven't, selected other prey, deer and livestock, moose - not so much, when they expanded into areas where those prey were a better fit to optimal foraging theory.

The sea otter, urchin, kelp, herring story is another one that makes sense. But this Orca story isn't making sense to me. I can understand preferring chinook. I prefer chinook too, as a matter of fact. But it doesn't take exclusive prey selection theory to persuade me to eat sockeye, coho, New York steak, chicken, or pork chops to satiate me and keep me far, far from starvation. I can understand having learned to hunt and select for chinook. What I'm having trouble with is the associated corollary that in the absence of chinook an Orca will choose starvation over the rather slight behavioral change to eat whatever fish is abundant, absent a clear, cogent, and convincing explanation. That's all I'm asking for, and then I could be a believer.

Sg