[obol] more harrassment

[Darrel Faxon]

OBOLites,
    An old thread by now, perhaps, but I'd like to add a couple of interesting cases, one new; one old.
Today behind the Marine Science Center, well out over the bay I saw a Belted Kingfisher being harrassed by a Barn Swallow.  The kingfisher was flying across the bay when, apparently sighting a fish, stopped to hover.  The swallow immediately dove on it from above, missing actual contact by inches.  After the assault, it climbed higher, and repeated the process, and then did it a third time, after which the kingfisher flew away.  Since the action took place nowhere even close to a swallow nest, it seems inexplicable to me why the swallow found this particular behavior offensive, coming as it did from a species which posed it no threat whatsovever.
    The most amusing case of harrassment I have observed took place about ten years ago on Alsea Bay.  A Pomarine Jaeger had come to those inshore waters just off the seawall to harrass some sterna terns which were flying around inside the bay.  Such behavior would be expected from a jaeger.  What made it amusing was that the jaeger only pursued the terns part of the time.  After each chase, it would land among the gull flock roosting on the sandbar on the north side of the river mouth.  It would sit sort of hunkered over looking for all the world as though it was pretending to simply be another gull.  However, every time a tern would fly by, it couldn't restist the temptation to crane its head around and watch the passage.  This action was a dead give-away, because it was totally different from the gulls, which just sat there.  The jaeger, try as it might to be unobtrusive, stuck out like a sore thumb because of its constant vigilance.  If two terns flew by at once, the jaeger was even more restless, and if the number of terns increased to three, it was more than the predator could stand.  It would immediately take to the air and give chase.  I watched this activity for more than half an hour, during which time the jaeger made probably seven or eight pursuit flights, and the rest of the time sat on the sandbar in his pretend mode.  It really was quite comical to watch.

Darrel
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