Although our 14th floor apartment suffers from the symphony of the neighbouring subway track and yard, it also enjoys a beautiful open view of the park north of our building. We get to see some wicked lighting storms move through, some fiery autumn colours and…. frequent bird swarming.
Apparently, in birds, this swarming is called flocking.
When you’re in the park or on the Kay Gardner path when the birds do their dance, everyone stops to watch in awe. The view from above is equally neat (the video does not do the experience justice).
Lloyd Scott of the Royal Society for the Protection of Birds explains that:
Recent scientific research has concluded that the way birds fly with ‘Red Arrow’ precision without colliding with one another is by each individual tracking the movements of just seven of their nearest neighbours. This leads to a domino effect in which millions of birds can potentially co-ordinate themselves without accident.
From The Straight Dope – Fighting Ignorance Since 1973 (“it’s taking longer than we thought”)
First, I should mention why animals aggregate in flocks, herds, and schools in the first place. While there are many reasons, the most pervasive seems to be that it serves as a defense against predators. Having many eyes together ensures that at least some will spot a predator while others are feeding, snoozing, or looking in the wrong direction. Once the group takes flight, the predator may have trouble focusing on a single target and become confused. It may also be physically dangerous for a predator to plunge into a seething mass of prey. In some cases, larger or more aggressive prey species may be able to offer a coordinated defense and fend off a predator that would make short work of an isolated individual.
Some species may also aggregate for social and reproductive reasons.
Regardless of why they do it, it’s a pretty neat perk of living in a large, impersonal apartment building!