The common brimstone undergoes some regional migration between hibernation and breeding areas throughout the year, as seen in the different chemical composition of butterflies across varying seasons and regions. In general, there is movement towards wetlands to reproduce. After the eggs hatch, develop, and pupate, newly hatched adult butterflies emerge and disperse locally into both woodlands and wetlands to overwinter. Butterflies travel to the woodlands for overwintering, and no mating appears to occur within these habitats. Overwintering also occurs in the wetlands, where the host plant alder buckthorn is abundant. After emerging from overwintering, adult brimstones that were previously in the wetlands are joined by those that hibernated in woodlands, and the population breeds and lays eggs.
