White clouds of a migration

The migration of the brownveined white butterfly (Belenois aurota) in South Africa takes place during midsummer every year, filling the sky with white clouds of butterflies, reports Alberton Record.

According to Johan van der Walt, who wrote a blog for Wildlife South Africa about the butterflies, the migration affects especially the central, northern and northeastern parts of South Africa.

Depending on climatic conditions like rain and drought, the numbers differ every year.

Following them are hundreds of insect-eating birds and dragonflies for which the slow-moving, low-flying butterflies are easy prey.

Known as South Africa’s most common butterfly and occurring in most areas of the country, the brown-veined white butterfly is also called pioneer, pioneer white or caper white.

Of the family Pieridae, with a wingspan of about 45mm, they originate in the dry regions of the Karoo and the Kalahari.

There they gather in their millions every year in December or January before taking to the sky to migrate in a northeasterly direction.

The butterflies, which lay their eggs on Shepherd’s trees (Boscia albitrunca), owe their population numbers to these trees, which are the main food source for the caterpillars.

The masses of white butterflies probably play an important role in the pollination of the trees, but not much is known about this ubiquitous butterfly.

After crossing the Northern Cape, parts of the Free State and the North West on their journey northeast, they fly across Gauteng, parts of Mpumalanga and parts of Limpopo.

More and more butterflies join the migration along the way. They also pause en route to lay eggs.

Van der Walt says little research has been done to determine where exactly the butterflies fly to, but they have been noticed flying above the ocean near the Mozambique coast, where at the end of their journey, they most probably fall into the ocean. – Caxton News Service

The butterflies, which lay their eggs on Shepherd’s trees, owe their population strength to the tree, which is the main food source for the caterpillars.

Johan van der Walt Blogger for Wildlife South Africa