Nymphalis antiopa

Introduction:

These butterflies have a lifespan of 11 to 12 months, one of the longest lifespans for any butterfly. It is the state insect of the U.S. state of Montana, adopted in 2001.
Life Cycle: Individual males will mate with multiple females throughout one breeding season. Spring marks the beginning of their mating season, when female mourning cloaks will find a host plant and begin to lay their eggs. Adult mourning cloak butterflies can first be seen in late spring through early summer. They will break diapause once some, though not all, of the butterflies start to migrate through September and October. They then overwinter, and then restart their mating cycle throughout the spring, from April through June.

Size 2.25 to 4 inches (5.7 to 10.1 cm)
Sexual Dimorphism: false
Metamorphosis: complete (egg, larva, pupa, adult)