Mourning cloaks, like all other butterflies, undergo complete metamorphosis. Egg →Larva (L1 ... L5) → Pupa → Adult. Before the leaves bud-out, Mourning cloaks are known to lay their eggs as ring clusters around the terminal twigs on host plants. The host plant selection is vital because it provides the food source for the young caterpillars. Females are known to have multiple broods, typically up to two to three. The newly hatched caterpillars will group together until they shed their skin—termed an instar for each shedding. This shedding event occurs four times throughout development in a process called ecdysis. The larvae experience a fifth skin shed to produce a fully grown caterpillar. The next stage in the mourning cloak's life cycle is to morph into a pupa and then cocoon in a process that encases the creature in a tan or gray chrysalis, which will hang from the stems of grass. This pupa stage allows for resting and further maturation. This metamorphosis takes approximately fifteen days. Following development as the chrysalis is the emergence of an adult mourning cloak butterfly. Studies show that the mourning cloaks use endocrine mechanisms similar to other lepidopterans to regulate female specific protein synthesis, oogenesis, and male and female reproductive gland development. Juvenile hormone (JH) is involved in the regulation of oogenesis and development of the male and female reproductive glands in the mourning cloak butterfly. Behavior The adult butterflies hibernate during the winter months. Typical locations of overwintering include tree cavities and on the ground underneath loose tree bark (covered by snow). They often emerge from hibernation before the snow has completely melted, making it one of the first butterflies to take wing in the spring. The mourning cloak is a non-migratory species but some sources suggest that a portion of the North American population migrates southward. Experiments carried out in Germany by Hubert Roer in 1962-68, documented a long-distance (one way) migration from Bonn to Greece (Chalkiditi). Ecology Larval food-plants Upon hatching, the caterpillars will begin to eat the leaves of the larval food-plant. A large number of food-plant plants was recorded, such as willow (Salix nigra, Salix pentandra, Salix caprea, Salix aurita, Salix cinerea, Salix phylicifolia), American elm, hackberry, hawthorn, wild rose, Betula species (Betula verrucosa, Betula chinensis), Alnus incana and poplar. The caterpillars live gregariously in communal silken nest on the host-plant, until they disperse prior to pupation. Adult mourning cloaks