Crazy Grackle

[phil adair]

This poor female Osprey, at I think it's a female (she spends most of her time on the nest) gets hassled by a Grackle anytime she leaves the nest. The Osprey's mate gets left alone.

Does anyone know why?

[Alfred Forns]

Female it is and no clue about the harassment ... must be personal :) .. will wait for John, I'm sure he has a good idea !!!

... excellent capture !!!

[John Chardine]

Oh boy, Phil and Al, this is tough, and I would be just hypothesizing but anyway ...............

First, just a question about how often this has occurred- would it be 5 of 5 or 25 of 25 times that the female gets mobbed?

The other point (and I'm clutching as straws here) is that individual birds have remarkably different feeding habits and I'm wondering if the female, once she leaves the nest, flies in a certain direction that prompts an attack from the grackle, while the male never ventures into the "grackle attack zone" or GAZ as we biologists call it!

I will add the Ospreys present no danger to a grackle, but like almost all birds, grackles have pea-brains and behave by "rules of thumb". The rule operating here is "attack any bird that looks like a predatory hawk and that flies into my GAZ". Ospreys are being caught in the cross-fire here and the behaviour is really aimed at falcons, accipiters, (and corvids) and the like.