Abstract
Understanding the seasonal movements of migratory species underpins
ecological studies. Nearly 600 butterfly species show migratory
behaviour, yet the spatial pattern of these migrations is poorly
understood. We developed climatic niche models for 405 migratory
butterfly species globally to estimate patterns of seasonal movement and
the distribution of seasonal habitat suitability. We discover strong
seasonal variation in habitat suitability for most of the migratory
butterflies with >75% of pixels showing seasonal change in
predicted occupancy for 85% of species. In contrast to bird migrations,
the greatest rate of seasonal switching occurs in the tropics. Several
species showed extreme range fluctuations, exceeding 10-fold for 53
species (13%) and more than 100-fold for nine species (2%); such
species may be at elevated extinction risk. Our results can be used to
search for the ecological processes that underpin migration in insects,
as well as to design conservation interventions for declining migratory
insects.