Sexual selection drives maladaptive learning under climate warming

Current predictions forthe effects of the climate crisis on biodiversity loss have so far ignored the effects of learning ability and sexual selection. Using the African butterfly Bicyclus anynana,which showsstrong phenotypic plasticity in response to temperature,we showthat learning produces a maladaptive mate preference under climate warming. We modelled climate warming and foundthat as temperature becomes an unreliable cue atthe onset of the dry season,adult butterflies displayed the wet season rather than the dry season form. Femalelearning further suppressed their innate, adaptive sexual preference for dry season males. Instead,females learned to prefer a phenotype transiently present during the seasonal transition. Female fertility and longevity were also affectedby learning,reducingfemalefitness following climate warming. Our results emphasize the importance ofsexual selection,learning,and their fitness consequences for understanding(mal)adaptation of natural populations to climate warming.