We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Detecting alternate foraging ecotypes in Australian sea lion ( Neophoca cinerea) colonies using stable isotope analysis.
- Authors
Lowther, Andrew D.; Goldsworthy, S. D.
- Abstract
Stable carbon (δ 13C) and nitrogen (δ 15N) isotopes are used frequently to describe the trophic ecology of top marine mammal predators. Australian sea lions (Neophoca cinerea) are one of the world’s rarest otariid seals and exhibit the highest levels of natal site philopatry of any seal. We report the development of a screening technique to identify different foraging ecotypes and assess their relative frequencies inAustralian sea lionbreeding colonies using stable isotope ratios in pups. Geospatial and dive data from 15 adult females at three breeding colonies revealed alternate foraging strategies (inshore and offshore foraging) that were reflected in significant changes in δ13 C and δ15 N. Isotope fractionation from mother to pup was validated using paired whisker and blood serum samples with no significant difference between δ13 C and δ15 N enrichment of +1.27‰(whiskers) and +1.92‰(blood serum) from mothers to pups. Isotope ratios from whisker samples representing over 50% of pups born at threecolonies revealed significant intercolony differences in maternal foraging ecotype frequencies. These results are unique in that ecologicalpartitioning over such a small spatial scale has not been described in any other otariid species.
- Subjects
FORAGING behavior; AUSTRALIAN sea lion; STABLE isotopes; NITROGEN content of seawater; MARINE mammals; SEAL behavior; PHILOPATRY
- Publication
Marine Mammal Science, 2011, Vol 27, Issue 3, p567
- ISSN
0824-0469
- Publication type
Article
- DOI
10.1111/j.1748-7692.2010.00425.x