Crows and selective mobbing

[cairnstone]

Over the years in my area I have seen crows mobbing predators countless times. There is one thing that stands out. They never bother Cooper's Hawks. Crows will freak out at everything from Red-tailed Hawks down to Screech Owls. I have even seen them mob a Turkey Vulture. The crows can be perched in the same tree as a Cooper's Hawk and totally ignore it. Last weekend I watched a group of crows mobbing a goshawk and the local Cooper's Hawk joined in with the crows (although the hawk complained from a bit of a distance not wanting to get too close). I don't recall ever seeing crows mob a Cooper's Hawk. Do they? Or is this just a local phenomenon?

[Reuven_M]

I don't think I've ever seen any issues between these two species either. I had a pair of crows and of cooper's nesting in my neighbourhood this summer - they totally ignored each other until a Great Horned Owl showed up and they started mobbing it together! I've seen the same thing in Guelph too with these two species mobbing a Great Horned together.

[Rotarran]

Interesting observations.

[Dinusaur]

Very interesting indeed. May be the size of Cooper's doesn't look threatening. I wonder though what happens when one has babies in the nest while the other comes too close. That will probably be the acid test. And then there are instances when table turns - a juvenile Red Tailed Hawk chasing a Common Raven in the sky over Downsview Park. And this is the not first time I have seen and photographed the incident. Are Ravens less aggressive than crows?
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