Phenotypic plasticity in hormonal and behavioural responses to changes in resource conditions in a migratory songbird

摘要: An emerging question in animal behaviour is whether and how behavioural plasticity will enable organisms to adjust human-induced, rapid environmental changes that affect breeding conditions. Adaptive response changing resource conditions depend on the sensitivity of neuroendocrine system food stimuli constraints mechanisms mediating expression reproductive behaviours. We tested hypotheses availability mediates androgen corticosterone (CORT) responses, circulating concentrations these hormones turn mediate investment into competing mating parental behaviours a migratory songbird. provided supplemental black-throated blue warblers, Setophaga caerulescens, habitats with natural low high abundance. The effects feeding were most pronounced food-poor habitat. During their social mates' fertile stage, fed males sang less near nest sites, had lower plasma CORT levels, higher residual mass than control males. Fed benefited indirectly from access because females more effort females. did not increase own effort. Our results suggest increased mate-guarding over extrapair mate attraction while mates invested additional resources territorial defence or self-maintenance during stage. These findings reveal plastic patterns covariation among endocrine parameters behaviours, but supplementation. responses enabled individuals rapidly adaptive change unlikely be constrained by hormonal underlying mediation