Which fruit bat forms the huge Kasanka National Park migration of up to 10 million bats?

The straw-coloured fruit bat forms the huge seasonal migration to Zambia’s Kasanka National Park, where up to 10 million bats gather.

The species is Eidolon helvum, one of Africa’s large Old World fruit bats and the continent’s most widely distributed megabat. Each year, usually from October through December, enormous numbers arrive at Kasanka’s Mushitu swamp forest. Their arrival coincides with the first rains and the ripening of fruits such as wild loquat and waterberry.

At peak density, the bats roost in an area of only about 2 hectares. The spectacle is often described as the world’s largest mammal migration or greatest known mammal aggregation, although exact totals are estimates and can vary. The Kasanka gathering was first discovered in 1980.

These bats are not flying foxes from Australia, despite the similar appearance and fruit-eating habits. They are African fruit bats, and they are important seed dispersers and pollinators. Their seasonal concentration also attracts predators, including eagles, pythons, crocodiles, and Nile monitors. The species is classified as Near Threatened because its population is declining.