I recently (6/9) visited a Caspian Tern nesting colony at the Everett,
WA Navy Station. There are several thousand terns here but one caught my eye.
It flew in with a fish in its bill, circled around a couple times, and landed
facing a sitting bird (presumably on eggs) as if offering the fish. The
proferred fish was not taken and after a few seconds the incoming tern flew
up. It circled around a couple more times and landed some 20 yards away and
offered the fish to a different bird. The results were the same. It again
flew up and landed near the original landing spot and offered the fish to what
I believe was a third bird (It's hard to keep them straight in a flock of at
least 1000 birds). Finally this bird took the fish.

Do Caspian Terns coming in from foraging have a difficult time
remembering where there nest site is? This particular colony is on what
appears to be an entirely flat and featureless lawn. Do they have a difficult
time recognizing their mate? Will brooding birds only take a fish offered by
what they believe to be their mate? Any comments?

Jim Elder
Seattle, WA
jime at eskimo.com