Wildlife

Clouded Yellow Butterfly: Welfare and Migration

Understanding the ecology and welfare of this spectacular migratory butterfly visitor to the UK.

Key Facts

Clouded yellows are annual migrants from southern Europe — not resident in the UK
In good years (clouded yellow years) thousands arrive in August and September
Larvae feed on clover and other legumes — the immigrant generation breeds before dying
Cannot survive UK winters — populations depend on annual immigration

Welfare Considerations

Clouded yellow welfare as a migratory species depends on habitat conditions across the entire migration range — from North African wintering grounds to UK clover-rich grassland for breeding. Welfare-informed grassland management maintains legume-rich swards that support immigrant breeding. Red clover and bird's-foot trefoil in field margins support the UK breeding generation.

What You Can Do

Report clouded yellow sightings to Butterfly Conservation during immigration years
Maintain legume-rich grassland margins that support immigrant butterflies
Support conservation work across southern Europe that protects clouded yellow source populations