How Do Moths and Butterflies Survive a New York City Winter?

by AMNH on

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What happens to butterflies and moths during winter in New York?

They may seem as delicate as gossamer, but moths and butterflies routinely survive the cold, harsh weather of New York winters. How do they do it? After all, they are small, without any insulating fur or feathers, and cannot generate their own body heat as mammals and birds do.

An Eastern comma butterfly with its bright orange wings with black flecks strikes a colorful contrast against the drab wicker surface on which it is perched.
Comma butterflies, like this Eastern comma, survive cold winters as adults by secreting chemicals that act as antifreeze within their own bodies.
Liza Daly

Some adult invertebrates like these overwinter in protected shelters. One way they withstand freezing temperatures is by secreting chemicals that act as antifreeze to prevent the formation of ice crystals in their bodies. The comma and mourning cloak butterflies are two such insects. (Visit The Butterfly Conservatory, now on view, to see hundreds of live, tropical butterflies from around the world.)

On milder winter days, with temperatures in the 40s°, these butterflies may even emerge to bask, their dark scales absorbing the heat of the sun.

Mourning cloak butterfly (Nymphalis antiopa)
Mourning cloak butterflies (Nymphalis antiopa) overwinter in protected shelters, sometimes emerging to bask on warmer days.
Jerry A. Payne/USDA Agricultural Research Service/

Winter moths such as straight-toothed sallow, Morrison’s sallow, and Grote’s pinion may also be seen on mild, humid winter nights, insulated by dense hairs on their bodies. 

Some adult invertebrates simply die when the cold weather arrives, leaving their offspring to survive in a protected dormant stage as eggs, larvae, or pupae. Woolly bears (caterpillars of the Isabella tiger moth) find protection under thick layers of leaf litter.

Banded woolly bear, the larva of the Isabella tiger moth
Banded woolly bears are the caterpillars of Isabella tiger moths.
Whitney Cranshaw/Colorado State University/

Below is an Isabella tiger moth as an adult.

Isabella tiger moth
Isabella tiger moths survive winter in the larval stage, as caterpillars; in warmer weather, they become active again, pupate, and later emerge as adults, like the one you see here.
Steve Jurvetson

And polyphemus moth pupae are sheltered in their cocoons during the winter.

Polyphemus moth cocoon on a bare branch.
Moths and butterflies undergo a four-stage metamorphosis from embryo, to larva, to pupa, and finally to the winged adults. Moths' pupae are often encased in a cocoon, as with the polyphemus moth's here.
Lacy L. Hyche/Auburn University/

Here's a polyphemus moth in warmer weather, as an adult.

Polyphemus moth
Kevin D. Arvin/

Photographed any winter moths or butterflies, or any other invertebrates, in New York City? Share them at New York is Wild!, the Museum's project at, where anyone can upload images and learn more about the wildlife of the City.

This post was adapted from this downloadable guidebook, written by Elizabeth A. Johnson.