Vic Smith wrote:

>Experiments in a German zoo have suggested that cormorants spreading their
>wings are actually warming up the cold fish they have just swallowed.
>In tests, every bird fed cold fish flapped its wings and spread them for
>about 20 minutes, while less than a quarter of those fed warm meals spread
>their wings.

This is fascinating news. I have also wondered if there might be some
thermoregulatory function in wing-spreading, and this could easily be
tested by looking at ambient weather conditions during bouts of spreading.
Another good research project.

>According to experts, this would not only be useful in aiding digestion, but
>it could help other cormorants, too [identifying good feeding areas]"

I'm still a bit confused about how this could help other cormorants
identify good feeding areas (especially because roosting cormorants are
pretty darned conspicuous, even when they don't spread their wings).
Perhaps the author was just picking up on the article about the Reed
Cormorant. Only socially feeding cormorants would benefit from other
cormorants knowing about *their* good feeding areas, and indeed, at least
some species of cormorants do feed socially and benefit from numbers of
birds present. I would say that most Double-crested in salt water around
here *don't* feed socially, however, probably less likely to than Brandt's,
which is not a wing spreader.

Dennis Paulson, Director phone: (206) 756-3798
Slater Museum of Natural History fax: (206) 756-3352
University of Puget Sound e-mail: dpaulson at ups.edu
Tacoma, WA 98416