Dennis:
>I dunno. My guess is that one eagle with moderate ease can cause desertion
>of a heronry of almost any size (although see below).

Yeah, I wasn't thinking in terms of disruption and abandonment, which
when there were plenty of potential heronry sites along, say, the
Willamette perhaps is a good strategy when confronted with something
as potentially permanent as an eagle nesting site.

>I know nothing about the effects of eagles on storkeries, ibisries, and
>spoonbilleries.

Nor I on breweries or wineries, but I do know that herons can effect
fish hatcheries, causing state employees to build screeneries.

- Don Baccus, Portland OR <donb at rational.com>
Nature photos, on-line guides, at http:://www.xxxpdx.com/~dhogaza