Clouded yellows are strong-flying migrants from southern Europe that arrive in the UK in variable numbers, with welfare linked to nectar availability and breeding habitat quality.
Migrating clouded yellow butterflies expend enormous energy crossing the sea and establishing in UK habitats. Individuals arriving in poor condition from adverse crossings have reduced survival prospects. Nectar availability at landing sites in southern England is critical for refuelling. Clover-rich habitats support breeding when conditions allow, with welfare of larvae depending on food plant availability. Their migratory lifestyle means individual welfare is tied to conditions across a vast geographic range from North Africa to the UK. Conservation of nectar-rich downland and coastal grassland in southern England provides crucial welfare support for arriving migrants.