Doug:

What you witnessed was an example of klepto-parasitism: one kind of
bird or animal letting another do the work and they snatch the reward.

I was introduced to this term early last spring by Roger Troutman.  He
responded to my similar list serv inquiry but in this case it was
gadwalls, as non-diving dabblers, helping themselves to the aquatic
vegetation that the diving coots were bringing up at WC Best Wildlife
Preserve here in Chardon.  Check out what Wikipedia has to say about
it for further information and examples.

Dan Best

On Nov 6, 2011, at 7:00 PM, Doug Overacker wrote:

> Julie Karlson and I stopped near the Corps of Engineers Visitor
> Center at
> Buck Creek State Park this morning to scan the lake for waterbirds. I
> started scanning the lake and spotted some Horned Grebes. A
> Bonaparte's Gull
> was there with them. I scanned some more and found another Horned
> Grebe also
> accompanied by a Bonaparte's Gull. Then I found a Pied-billed Grebe
> and it
> was also accompanied by a Bonaparte's Gull. I watched the grebe dive
> and the
> gull flew. Soon the grebe came up and the gull landed right next to
> it.
> Again the grebe dove and the gull flew only to land next to the
> grebe when
> it came up. It repeated this one more time while I watched. My guess
> is that
> if any of the grebes came up with a small fish the gull would try to
> claim
> it. Are there any other explanations?
>
> Doug Overacker
> Springfield, Ohio
>
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