That could be the case in Bill's example, who knows, but it does remind me of a story I heard from a woman I recently did a CBC with who described (if I'm remembering correctly) a Cooper's who had learned to use her sliding glass door as a backstop for pinning unsuspecting California Quail.
In my memory it wasn't using the window as a shock absorber but an aid to pinning and killing the prey. Interestingly in both stories it was a larger bird being put on the glass.
On Tue, Feb 27, 2018, 22:59 Nathaniel Wander <nw105...> wrote:
> Hiyah Bill, > > I don't believe that hawks use their prey as collision rebound devices; > I've never seen or heard of such a thing. It also sounds like more > planning/better built-environment sense than a hawk might have enough brain > cells for, especially when doing all the other calculations necessary to > take prey on the wing. I'm not sure their eyes are up to it either. > > For example, an American Kestrel has nearly twice the visual acuity of a > human, but its peak resolution maintains only over a range 55% as wide as a > human's. That sounds like a design for exquisite viewing of what's right > in front of it's beak, but not such great peripheral vision--which makes > sense, given how it makes its living. > > Added to all the other vulnerabilities bird's have for crashing into plate > glass, the limited peripheral vision of raptors--other kinds of birds may > need better peripheral vision to steer clear of them--just increases their > chances of crashing. Accipiters are the raptors most likely to hunt around > human habitation, especially when attracted into our yards by feeder birds; > hence, the most likely to glass-crash. > > I'd say that was one very lucky Sharp-shinned and one humiliatingly > unlucky dove. > >