Along the rivers in the hot plains of Australia where the kangaroos rest in the shadows of the eucalyptus trees and the Kookaburra bird laughs like crazy above the water, the Australian Butterfly sometimes swarms in thousands. These brilliantly colored Pierids are related to our own common white and yellow butterflies that also swarm in great numbers across Iowland roads in summer. The swarming means that some thousands out of millions of eggs laid a couple of months before on the fresh green plants brought by the rains have now come to maturity. But, before they could become butterflies, many millions of caterpillars were eaten by furiously hunting birds. The butterflies themselves swarm forth over the land hunting for new places to lay their eggs where the ephemeral rainstorms of vast dry Australia bring a brief flowering of green life.
Australian Butterflies are not very strong fliers, but they often like to swirl together in groups, almost seeming to dance in the shimmering hot air of summer. Muddy pools on dirt roads of the “Outback,” as the Australians call their great interior desert-like country, lure many of the Australian Butterflies to drink at their edges, even as similar Pierids in our country come to drink at such places after a rain. In fact the whole life of the Australian Butterflies circles around the coming of the rain. When the dry season is long and terribly hot, this butterfly seems to completely vanish and it must be true that almost all of them are killed out by the heat and dryness. But let the rain come and renew the greenness of the land and suddenly this beautiful red, black, white, and yellow butterflies swarm again.