One of the longest-lived butterflies in the world (up to ten months) is the Mourning Cloak (Nymphalis antiopa), a brush-footed butterfly in the Nymphalidae family. This butterfly may be called Camberwell Beauty, Mourningcloak,… depending upon where you are from and is a friendly beauty. It was given its name because it looked much like it was wearing the dark cloak of mourning.
The wingspan is 2 1/4" to 4" so the Mourning Cloak is in the medium- to large-sized category of lepidoptera. They look like tree bark when their wings are closed up as they are a brownish-black colour. When their wings are wide open, on their purplish-black wings there is a creamy margin, almost yellow in colour, as a border on the outer wings, with a row of iridescent blue dots just along the inner edge of the border.
The Mourning Cloak uses trees for their host plant so if you have trees in the following families: Willow (Salix), Elms (Ulmus), Cottonwood, (Populus deltoides), Hackberry (Celtis occidentalis), or even Aspen (Populus tremuloides) then you may want to check for a grouping of about 30 or so eggs, usually oviposited (laid) along a twig! It takes a bit over a week for the larvae to hatch and then, as a group, the little ones begin their munch and poop-fest for the next couple weeks.
A gregarious group, Mourning Cloak larvae (caterpillars) do everything in their little family group until it is time to go find a place to pupate so chances are, you will spot a group of these bristly caterpillars together. Like all lepidoptera, the majority of a butterfly's nutrition is consumed in the larval stage.
When ready to pupate, they will leave the host plant to seek a nice, quiet place to undergo metamorphosis.
As adults, the Mourning Cloak prefer tree sap so you may find these butterflies near your trees! (In my garden, they prefer my Buddleia for nectar…yet, they do seem to like to bask on the branches of the Plumeria.) They overwinter as adults, usually in cracks and crevices in trees (they do camouflage so well!), emerging in the fall. This is probably why you will see them fluttering about nearly year-long.