brg_admin | Aug 1, 2019 | 0
Beaverton Bird Watch: Ravens vs Raptors
By Anne Harris
Part of the fun of bird behavior is figuring out why they do the perplexing things they do.
Take “mobbing,” for example. Mobbing is a coordinated swarming technique employed by some birds, like crows, to oust competitors or predators from their territory by making a lot of noise and annoying the heck out of their target by obstructing its flight path.
Beaverton’s most common raptor (bird of prey) and frequent object of crow-mobbing is the red-tail hawk (Buteo jamaicensis), a 36-inch-long, 2-1/2 pound hunter with a wingspan of around 3 feet.
Perhaps you’ve noticed them spiraling in the sky far above you on the updrafts that carry them effortlessly over their wide-ranging hunting grounds, often silently, but sometimes calling (in a screech that’s been hijacked by Hollywood to speak for all hawks, falcons and even eagles) to its lifelong mate or its young.
Personally, I’d think twice about playing chicken with a chicken hawk capable of mid-flight barrel rolls and 120 mph nose dives, but the raven versus raptor mobbing ruckus rarely ends badly; the red-tails move on down the road and the crows resume taunting people and each other.
Anne Harris is a local author who finds watching her avian neighbors quite fascinating as they loudly inhabit a mixed stand of conifers and broadleaf trees behind her home. “Provide food and they will come,” is what she discovered, and has been avidly studying their diverse habits ever since.