Breeding success of a marine central place forager in the context of climate change: A modeling approach
Résumé
In response to climate warming, a southward shift in productive frontal systems serving as the
main foraging sites for many top predator species is likely to occur in Subantarctic areas. Central
place foragers, such as seabirds and pinnipeds, are thus likely to cope with an increase in
the distance between foraging locations and their land-based breeding colonies. Understanding
how central place foragers should modify their foraging behavior in response to changes in
prey accessibility appears crucial. A spatially explicit individual-based simulation model (Marine
Central Place Forager Simulator (MarCPFS)), including bio-energetic components, was built to
evaluate effects of possible changes in prey resources accessibility on individual performances
and breeding success. The study was calibrated on a particular example: the Antarctic fur seal
(Arctocephalus gazella), which alternates between oceanic areas in which females feed and
the land-based colony in which they suckle their young over a 120 days rearing period. Our
model shows the importance of the distance covered to feed and prey aggregation which
appeared to be key factors to which animals are highly sensitive. Memorization and learning
abilities also appear to be essential breeding success traits. Females were found to be most
successful for intermediate levels of prey aggregation and short distance to the resource,
resulting in optimal female body length. Increased distance to resources due to climate warming
should hinder pups' growth and survival while female body length should increase.
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...