[CT Birds] Plankton feeding gulls

paul cianfaglione pgcianfaglione at gmail.com
Thu Mar 1 11:48:48 EST 2012

I really enjoyed the discussion about plankton feeding gulls. At first, I
had a hard time wrapping my mind around the idea of gulls with large bills
feeding on microscopic organisms. But after reading about Herring Gull
feeding habits, I guess it is certainly something to consider. Below is a
small excerpt from The Birds Of North America Online regarding Herring Gull
feeding habits;

*At sea, forages in large, widely scattered groups that coalesce quickly
through rapid recruitment when prey concentrations located (**Hoffman et
al. 1981*<http://bna.birds.cornell.edu/bna/species/124/articles/species/124/biblio/bib061>
*, **Pierotti 1988*<http://bna.birds.cornell.edu/bna/species/124/articles/species/124/biblio/bib099>
*). Often follows foraging humpback whales (Megaptera novaeangliae) or
groups of delphinids. Hovers over feeding groups grabbing fish, squid,
zooplankton concentrated at surface by mammals, diving birds, or large
predatory fishes swimming underneath concentration (**Pierotti

I understand that gulls may shift foraging patterns to take advantage of
short-term fluctuations in food supply. It just seems inefficient for gulls
to feed on microscopic plankton unless they are taking in massive amounts
at a time.

As an alternative thought, could gulls that attend plankton concentrations
be feeding on other prey items?? Many types of fry fish feed on plankton.
What may appear to be plankton feeding,  could in fact be opportunistic fry
fish feeding.

Paul Cianfaglione

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