[MARMAM] New publication on foraging ecology of Antarctic fur seals.

[Tiphaine Jeanniard du Dot]

Dear all,

I am pleased to announce the publication the article entitled 
'Reproductive success is energetically linked to foraging efficiency in 
Antarctic fur seals' paper in PLOS ONE.

Direct link: 
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0174001

Abstract:

The efficiency with which individuals extract energy from their 
environment defines their survival and reproductive success, and thus 
their selective contribution to the population. Individuals that forage 
more efficiently (i.e., when energy gained exceeds energy expended) are 
likely to be more successful at raising viable offspring than 
individuals that forage less efficiently. Our goal was to test this 
prediction in large long-lived mammals under free-ranging conditions. To 
do so, we equipped 20 lactating Antarctic fur seals (Arctocephalus 
gazella) breeding on Kerguelen Island in the Southern Ocean with tags 
that recorded GPS locations, depth and tri-axial acceleration to 
determine at-sea behaviours and detailed time-activity budgets during 
their foraging trips. We also simultaneously measured energy spent at 
sea using the doubly-labeled water (DLW) method, and estimated the 
energy acquired while foraging from 1) type and energy content of prey 
species present in scat remains, and 2) numbers of prey capture attempts 
determined from head acceleration. Finally, we followed the growth of 36 
pups from birth until weaning (of which 20 were the offspring of our 20 
tracked mothers), and used the relative differences in body mass of pups 
at weaning as an index of first year survival and thus the reproductive 
success of their mothers. Our results show that females with greater 
foraging efficiencies produced relatively bigger pups at weaning. These 
mothers achieved greater foraging efficiency by extracting more energy 
per minute of diving rather than by reducing energy expenditure. This 
strategy also resulted in the females spending less time diving and less 
time overall at sea, which allowed them to deliver higher quality milk 
to their pups, or allowed their pups to suckle more frequently, or both. 
The linkage we demonstrate between reproductive success and the quality 
of individuals as foragers provides an individual-based quantitative 
framework to investigate how changes in the availability and 
accessibility of prey can affect fitness of animals.


-- 
Tiphaine Jeanniard-du-Dot, PhD
Marine Mammal Research Unit
2202 Main Mall, AERL bldg
University of British Columbia
Vancouver, BC, V6T1Z4, CANADA
Tel:+1-604-822-9150 / cell:+1-604-724-4230