Chestnut heath (Coenonympha glycerion)

Chestnut Heath (Coenonympha glycerion)

The Chestnut Heath is a small, subtly beautiful butterfly in the Nymphalidae family (subfamily Satyrinae — the browns and heaths). It is closely related to other Coenonympha species but is distinguished by its darker, rich chestnut hues and delicate eyespots. The species thrives in warm, flower-rich grasslands, forest clearings, and hilly meadows.

🦋 Identification

• Wingspan: 30–36 mm
• Upperside:
  • Generally brown to dark chestnut, sometimes with an orange tinge
  • Often lacks prominent markings on the upper wings
• Underside (hindwings):
  • Greyish to brownish background
  • A delicate row of small white-ringed eyespots along the edge (submarginal ocelli), sometimes nearly absent or reduced in some individuals
  • The hindwing underside often has a silvery or dusted appearance
• The overall coloring gives it a soft, muted look compared to more brightly marked heaths.

🌿 Habitat

• Prefers warm, dry to moderately moist grasslands, including:
  • Open meadows
  • Forest edges and clearings
  • Hilly pastures and steppe grasslands
  • Occasionally in sparse woodland glades
• Often found where grasses grow tall and wildflowers are abundant.

🌱 Food Plants

Larval host plants:

• Grasses, particularly:
  • Sheep’s fescue (Festuca ovina)
  • Tufted hair-grass (Deschampsia cespitosa)
  • Other meadow grasses

Adult nectar sources:

• Feeds on a variety of flowers, including:
  • Thistles
  • Knapweeds
  • Dandelions
  • Wild marjoram

🔁 Life Cycle

• Univoltine: One generation per year
• Flight period: May to August, depending on region and altitude
• Eggs: Laid singly on grasses
• Larvae:
  • Feed on grass blades
  • Overwinter as partially grown caterpillars
• Pupation: Occurs low in vegetation in spring

🌍 Distribution

• Found across central and eastern Europe, extending into:
  • The Balkans
  • Russia
  • Parts of Western Siberia
• More localized in Western Europe, generally absent from the far west and the British Isles

🛡️ Conservation Status

• IUCN Red List: Not globally threatened
• Locally vulnerable to:
  • Habitat loss due to agricultural intensification
  • Succession (loss of open grasslands to shrubs and forest)
  • Overgrazing or complete abandonment of traditional grazing practices
• Conservation relies on maintaining semi-natural grasslands through extensive grazing or mowing.

🧬 Interesting Facts

• The degree of eyespot development varies considerably among individuals and populations.
• Often flies low over the grass, making short, weak fluttering flights.
• Its subtle beauty makes it a favorite among butterfly specialists and nature photographers who appreciate Europe’s grassland biodiversity.

The Chestnut Heath (Coenonympha glycerion) is a quiet but important part of Europe’s rich butterfly fauna. Its dependence on healthy, traditionally managed grasslands makes it a good indicator species for grassland conservation.