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Mourning Cloak

Nymphalis antiopa

Mourning Cloak

Adults Fly

March–April (overwintered adults) and June–October (new adults).

Eggs Laid

April–May (shortly after adults emerge from winter shelter).

Larvae Active

May–June (often in noticeable groups on host branches).

Overwintering

Overwinters as an adult in protected crevices (bark, wood piles, rock cracks, outbuildings).

Conservation (NatureServe)

G5 (Secure)
Widespread; local declines can occur where host trees are removed from waterways.

Caterpillar Host Plants (Willamette Valley natives)

  • Scouler's willow Salix scouleriana
  • Pacific willow Salix lucida ssp. lasiandra
  • Black cottonwood Populus trichocarpa
  • Sitka willow Salix sitchensis

Favorite Nectar Flowers (Willamette Valley natives)

  • Tall Oregon grape Mahonia aquifolium — Early spring blooms; great ‘wake-up’ nectar.
  • Red-flowering currant Ribes sanguineum — Early spring nectar; hummingbird favorite too.
  • Osoberry Oemleria cerasiformis — Very early bloom; supports early pollinators.
  • Thimbleberry Rubus parviflorus — Spring nectar in woodland edges.
  • Common yarrow Achillea millefolium — Summer nectar when they switch to flowers.

What the Caterpillars Eat

Leaves of willows (Salix) and cottonwoods (Populus); feeding can look dramatic but hosts usually recover.

If you spot a large, dark butterfly cruising through late winter sunshine, there’s a good chance it’s the Mourning Cloak. Its deep maroon wings are trimmed with a pale yellow edge and sprinkled with iridescent blue spots—like stained glass at dusk.

This species is famous for its timing: it overwinters as an adult, tucked into bark crevices or other sheltered places, then reappears early in spring when very few butterflies are flying. Because early flowers can be scarce, adults often sip tree sap and feed on fermenting fruit.

Caterpillars feed in groups on native trees and shrubs—especially willows and cottonwoods—and later the fresh adults emerge in early summer. In good years, Mourning Cloaks can be among the longest-lived butterflies you’ll meet in Oregon.

Fun Facts

  • Mourning Cloaks are among the longest-lived butterflies—some individuals can survive nearly a year by overwintering as adults.
  • Adults often prefer tree sap and rotting fruit, so you’ll sometimes see them on damaged trees or fallen apples rather than on flowers.

Sources

Solitary wasp

A solitary wasp has no colony of workers helping raise her young. A female may stock her own nest cells with food, or find a host for her developing offspring. Solitary describes social life; parasitoid describes a feeding strategy. A wasp can be both.

Social wasp

Social wasps share a nest and cooperate in raising young. In yellowjacket and paper wasp colonies, reproductive females lay eggs and workers help feed the brood and maintain the nest. They can defend that nest, so observing a forager is different from approaching a colony.

Non-native Social wasp

This is a social wasp introduced beyond its natural range. In this case the European paper wasp was introduced to North America from Europe, probably hidden in shipping materials. Non-native describes its origin, while social describes colony life.