Friend of Dale:

>So, I'm having my morning cup of tea at the beach yesterday, watching a
>group of white-winged scoters dive for crabs. An otter slips into the
>water nearby and swims out to grab a duck for breakfast. But, the
>scoters spot the otter in time and take off, uttering an alarm call: a
>distinctive repeated sequence of four sounds, like
>"er.er.er.er.....er.er.er.er...." A seagull hears this and flies over, making
>the same call, same sequence, only higher and squeakier. The seagull
>does this once or twice. This attracts other gulls, and they mob the otter,
>making more typical seagull screams, until the otter leaves the water.
>Later, two otters swim by in the opposite direction, scaring off a scoter
>and later a female bufflehead. Scoter makes the same er.er.er.er... call,
>and so does the bufflehead: sped up, in pitch between the scoter and
>the seagull, but still the same, distinct call sequence. So, whaddya
>know? Any pointers to more info on cross-species communication, if
>that's what it was? Do birds in common habitats with common threats
>have a common ("pidgen") language?

It's well known that a lot of passerine birds have more or less similar
predator-alarm calls. That's perhaps why pishing and squeaking work
broad-spectrum.

I've never heard anything about this in seabirds, however (or in pidgens).

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
web site: http://www.ups.edu/biology/museum/museum.html