Hermit Thrush agonistic behavior
Today, two Hermit Thrushes iwere facing off in my backyard. Each remained rigidly motionless, facing the other, several inches apart. They were hunkered down low on the ground, each with their tails fully fanned out. They remained, motionless, in this position for a minute or so, then briefly tussled before resuming exactly the same stationary position for minutes.
I missed the moment when this finally broke up - when I looked again, only one was present, hopping around the yard, puffing up its breast feathers and repeatedly fanning its tail. Victory?
From checking the Birds of the World site, it looks like this is a known agonistic behavior of the species, and they'll defend wintering territories, so this looks like two overwintering arrivals fighting over which one gets to set up turf in my backyard. New behavior for me!
A nice burst of raptor migration over Noe Valley this afternoon (roughly 1:30-2:30pm) included a single adult Broad-winged Hawk (second of the fall for me at home), as well as many Red-tailed Hawks, Turkey Vultures, and a few Red-shouldered and Cooper's Hawks.
-- Adam Winer