Bird collisions

Do birds collide in flight?

Yes.

Unfortunately, this question is often begged (question’s answer assumed rather than sought), so it is often phrased as: Why don’t birds collide when flying close together? A responder then must struggle with the daunting task of explaining the truth of something that is false. 

Now, birds are remarkably good at avoiding collisions and this fact does merit an explanation. However, they are not perfect at it. While avoidance is important, equally important seems to be the rapid recovery from inevitable collisions.

This shot into a flock of Snow Geese shows two collisions. In the upper centre right, two birds are colliding, while in the lower centre, three birds are.

Earlier this week, I was watching Cliff Swallows coming and going from the nests they had built on a human structure. While ascending to adjacent nests two of them collided.

Interestingly, a fifth of a second later each bird had recovered and continued on its way.

Of course, I have been discussing inadvertent collisions. During an attack, a raptor frequently collides with another bird. Indeed, falcons will purposely collide with prey so as to kill it. I lack a picture showing this, but do show one of an eagle about to collide with an osprey in its (successful) attempt to steal the osprey’s fish.