Nymphalis Antiopa - Appearance and Behaviour

Appearance and Behaviour

Nymphalis antiopa has a wingspan of 62–75 mm. The upper side of the butterfly is colored in a very dark red, with a bright, yellowish border around the wings. There is a darker band with bright blue spots between the border and the dark red inner side. Sexes are similar, although the females are slightly larger.

These butterflies lay eggs in clusters around twigs of their favored food plants, in Europe, generally Grey Willow (Salix cinerea) and in North America, generally Black Willow (Salix nigra) but also other willow species, as well as poplar, elm, birch, and hackberry. The larvae feed gregariously, and are black and spiny, with fine white speckles, and a row of red spots running down the back. They disperse to pupate and emerge after about three weeks. Soon after emergence, they will disperse further from their breeding grounds in order to find food (sometimes nectar, but more commonly tree sap) to build up fat stores for hibernation, and will often enter parks and gardens to do so. They are single-brooded and hibernate as adults.

Throughout its range, this species is generally considered a butterfly of woodlands, though it may occasionally be found in drier areas such as the deserts of western North America. During migration, they may be found in almost any habitat. The Mourning Cloak was adopted as the state butterfly of the State of Montana in 2001.