Mimicking wild megaherbivore behaviour: does ‘mob-grazing’ benefit moths?

Abstract

Lepidoptera are a highly diverse order of insects, providing essential pollination services and food for higher taxonomic groups. However, many common and widespread species of moth are in decline. High cattle stocking rates associated with intensive farming are known to be detrimental to moth abundance and species richness. Regenerative farming practices are on the increase, including ‘mob grazing’, which aims to mimic the grazing behaviour of wild megaherbivores by increasing herd numbers but also pasture rest periods. Anecdotal evidence suggests that this could be beneficial for biodiversity, but there is limited scientific evidence to support this. We investigate whether mob grazing cattle is beneficial for moths in comparison to more widespread ‘set-stock’ grazing systems. We measured abundance and species richness of moths, in both larval and adult form, in thirteen mob grazed fields and thirteen set-stock fields across Scotland (United Kingdom).