They are commonly known as brimstones for the bright yellow colour of the wings of most species.

Male brimstone butterflies can withstand cooler temperatures and are able to fly after just 4 months in hibernation.

Female brimstone butterflies need warmer climates to survive, and therefore are in hibernation longer.

The male butterflies have a longer life span as they are more resilient to a wider range of temperatures, unlike the female.

Early male emergence and reproductive phenology of the adult overwintering butterfly gonepteryx rhamni in Sweden.