Animal ecologist Lars Pettersson at Lund University recently asked me to illustrate how to survey butterflies; the surveyor walks a certain route and notes every butterfly within an imagined 5x5x5 meter box.
The foreground Large Blue Butterfly has an interesting lifestyle. Its caterpillars secrete a sweet substance that attracts a species of red ant. The ants take the caterpillar to their nest and eat its secretions. After wintering in the tunnels the caterpillar begins to feed on the ant's eggs and larvae. Then it hangs itself in the nest's roof and builds a chrysalis around itself. After three weeks it is transformed into a butterfly, crawls out of its chrysalis, and flies away to find a mate.