All tagged migration

The greatest shoal on Earth

Popularly known as the “greatest shoal on Earth”, the KwaZulu-Natal sardine run involves tens to hundreds of millions of Pacific sardines packed into high density shoals to make the annual trip from the coast of South Africa to spend the winter in the Indian Ocean.

For sheer size and spectacle, this marine migration is no less impressive than the wildebeests on terra firma. But unlike the Serengeti herds, which migrate in search of food, the underlying reason for the sardine run is much less clear.

On the wing: genetic compasses

Every year, tiny songbirds - some weighing as little as 3 grams - set off on an incredible journey. Often travelling alone and at night, they fly as much as 15,000km between their winter and summer homes, yet somehow manage to return to the same location every year. But how do these birds know where to go?