How Do Mourning Cloak Butterflies Fly in the Cold of Early Spring?

Male Morning Cloak butterfly (Nymphalis antiopa);NPS, Richard Lund,2002
Male Mourning Cloak butterfly (Nymphalis antiopa); NPS, Richard Lund,2002

Mourning Cloaks make their first appearance early in spring. They are large black butterflies with iridescent blue spots along the gold-trimmed hind edge of their wings.

Mourning Cloaks are not the earliest butterflies to emerge in spring, but they are still out before most butterflies.

The first adults of the spring emerge looking raggedy. The wings may be torn and worn along the edges. This is because of how the butterflies spend the winter.

Mourning Cloaks don’t migrate but spend the winter in cold areas in hibernation. The sleep through the coldest times of the years. Being cold-blooded insects they can’t make enough body heat to keep themselves active through the cold season. But, they can be active in cold weather for short periods of time.

How Do They Survive the Cold?

The same way other hibernating insects do with the help of an anti-freeze like substances called glycerols in their blood.

Mourning Cloaks find nooks, crannies, and crevices of places like tree bark to wedge themselves in to protect themselves from the cold. The butterfly does hibernate through most of the winter.

They can emerge as early as February to feed on the sap running in trees.  I think I have seen butterflies in February or March once or twice.

Before emerging in mid-winter, Mourning Cloaks shiver and raise their body temperature up to fifteen degrees warmer than the surrounding air. This enables the butterfly to emerge while the air temperature is still cool for most butterflies.

As the sun goes down they return to their crevices.

Factoid: When this big butterfly strays to England in the British Isles, it is called the Camberwell Beauty.

Mourning Cloak Butterfly Facts

Common name: Mourning Cloak
Scientific name: Nymphalis antiopa
Wingspan: Averages 3.0 inches
Family: Nymphalids (Brush-Footed)
Range: All regions of the United States
Habitat: Wandering and adaptable in woodlands, parks, suburbs, swamp edges, river bank edges
Host plant(s): Varies widely: Willows, elms, cottonwoods, aspens, birches, hackberry, and other broadleaf trees.
Adult food: Sap and decaying matter; occasionally nectar during summer
Note: Broad yellow wing edges

More Mourning Cloak Information

Nymphalis antiopa – Animal Diversity Website

Mourning Cloaks (Nymphalis antiopa) – North American Butterfly Association – Massachusetts Butterfly Club Chapter

The 6 Butterfly Families and Identifying Butterflies

The Adult Butterfly (Butterfly Life Cycle )

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