The marsh fritillary is one of Britain's most threatened butterflies, with welfare implications for colonies facing habitat loss and climate disruption.
Marsh fritillary colonies face welfare challenges at the level of individual larvae whose food plant becomes scarce in overgrown or drought-stressed habitat. Parasitoid wasp infections cause mortality in larval clusters. Habitat fragmentation prevents natural recolonisation after local extinctions from these natural population crashes. The welfare of individual insects in declining butterfly populations is increasingly considered in conservation planning as evidence for invertebrate sentience grows. Habitat management that maintains appropriate sward structure directly supports colony viability and individual welfare.