How do flocks of birds all change direction at the same time, like they've got one mind between them?

Question

When you watch a flock of birds they swoop and dip and change direction all at the same time - like there's some kind of communal intelligence or brain telling them what to do. It's not a case of 'follow the leader', they really do change direction at the same time. You also see this with shoals of fish. How does this happen?

Answer 1

Not sure if this is right but I think it a good way of explaining it.

Think of it as yourself in a crowded street. How do you and the other people around you avoid each other? It same concept.

The birds think logically. They think of the best route to go and, as you say, they are in a flock. Think of this as you with going out with family or friends together. Your not just going to leave them and go off on your own are you or leave one of the others on their own are you?

They are like a convoy, they can show each other what is going on in their own way which, for some animals (such as cats and dogs) is body language. If they see on bird at the front about to turn, they will do the same, as not to get left behind or left on their own.

It could be reactions, like driving a car. When one bird sees the others turning, it does the same, like the driver applying the brakes when the car infront does the same. It won't happen at the same time, there will be a split second difference, the same as the birds. They look like they are doing the same thing the same time when, actually, they aren't

Answer 2

Dave C is right - the movement isn't quite simultaneous. The reason it's so quick, though, is purely instinct. Instinct tells the rest of the flock that the bird(s) at the front are leading the way. A change in direction at the front is followed almost instantaneously by the rest simply because they do not pause to evaulate whether or not to follow - instinct just tells them to do so. It works in almost the same way as animal will take flight when it senses danger. It doesn't try to work out if that danger is real or what kind of threat it poses. As soon as it senses the threat it runs and if you've ever watched wildlife programmes you'll know that reaction is extremely quick.

Answer 3

Communal intteligence implies that the birds all move at the same time, but they actually do not. There is a lag time between the front and back of the flock.

One theory is that the birds can sense the change in pressure when the turn is initiated.

Another theory is the birds see the movement and move to keep the other birds in front in the same position and to avoid collisions.

Answer 4

No incestuous relationships , no inter species relationships, no pedophiles .... in basic terms gay relationships . definite , gay marriage should be legalized . this question is getting real previous . i ought to like an evidence as to why everybody is so conceited in believing that this may by technique of any ability damage them or society . we ought to leave the gays on my own already and get on with our lives .

Answer 5

Shortwave radio.