Energetic trade-offs in migration decision-making, reproductive effort, and subsequent parental care in a long-distance migratory bird

Migratory species trade-off long-distance movement with survival and
reproduction, but the spatiotemporal scales at which these decisions occur
is relatively unknown. Technological and statistical advances allow
fine-scale study of animal decision-making, improving our understanding of
possible causes and therefore conservation management. We quantified
effects of reproductive preparation during spring migration on subsequent
breeding outcomes, breeding outcomes on autumn migration characteristics,
and autumn migration characteristics on subsequent parental survival in
Greenland white-fronted geese (Anser albifrons flavirostris). These are
long-distance migratory birds with a ~50% population decline from 1999 to
2022. We deployed GPS-acceleration devices on adult females to quantify up
to five years of individual decision-making throughout the annual cycle.
Weather and habitat-use affected time spent feeding and overall dynamic
body acceleration (i.e., energy expenditure) during spring and autumn.
Geese that expended less energy and fed longer during spring were more
likely to successfully reproduce. Geese with offspring expended more
energy and fed for less time during autumn, potentially representing
adverse fitness consequences of breeding. These behavioural comparisons
among Greenland white-fronted geese improve our understanding of fitness
trade-offs underlying abundance. We provide a reproducible framework for
full annual cycle modelling using location and behaviour data, applicable
to similarly studied migratory animals.