Birdcall alarm systems

BIRDS call for all kinds of reasons: to announce they’re ready to mate, to warn others off their territory, to say they’ve spotted the sun or a juicy bug, and also, to tell others that there is trouble about.

When birds spot a predator, they call frantically, alerting their friends and neighbours. The alarm spreads extremely rapidly; some studies have found it travels over hills and mountains at more than 100 miles/hour (160km/hour).

Bird call alarms are also picked up by other species. Mice, rabbits, meercats, deer, squirrels and other animals will freeze when they hear bird alarms and then check for danger. Scientists think that some species may deliberately live near bird colonies, just to benefit from the aerial alarm system.

In addition to calling, the birds will also jump around, flapping their wings. It’s exactly what we human people do when we’re afraid: we scream, jump up and down, and flap our arms.

But some birds go one step further: they will gather together and fight off predators. It’s an amazing thing to see because birds aren’t gentlemen. When they swoop on an attacker, they go all out, bashing away with their wings, pecking, dive bombing and even pooping on the enemy.

Ornithologists call this “mobbing” and see it often in bird species, including crows, jays, terns and blackbirds. Usually it is limited to birds mobbing other birds as well as cats, dogs, and other animal predators. However, they sometimes sight and target humans – usually the ones who kill them, hurt them or destroy their nests. –

Ellen

Whyte