Foraging strategies of female elephant seals from Península Valdés, Patagonia, inferred from whisker stable isotope signatures of their pups

The foraging strategies of gestating female elephant seals (Mirounga leonina) from Península Valdés, Patagonia, were assessed by analyzing the values of stable isotopes of carbon (C) and nitrogen (N) from whiskers of 60 weanlings as a proxy for maternal spatial niche utilization. The data were combi...

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Published in:Aquatic Mammals
Main Authors: Eder, EB, Muelbert, MMC, Hindell, MA, Davis, RW, Rodriguez, DH, Lewis, MN
Format: Article in Journal/Newspaper
Language:unknown
Published: Western Illinois University Regional Center 2019
Subjects:
Online Access:https://eprints.utas.edu.au/40032/
id ftunivtasmania:oai:eprints.utas.edu.au:40032
record_format openpolar
spelling ftunivtasmania:oai:eprints.utas.edu.au:40032 2023-05-15T16:05:40+02:00 Foraging strategies of female elephant seals from Península Valdés, Patagonia, inferred from whisker stable isotope signatures of their pups Eder, EB Muelbert, MMC Hindell, MA Davis, RW Rodriguez, DH Lewis, MN 2019 https://eprints.utas.edu.au/40032/ unknown Western Illinois University Regional Center Eder, EB, Muelbert, MMC, Hindell, MA orcid:0000-0002-7823-7185 , Davis, RW, Rodriguez, DH and Lewis, MN 2019 , 'Foraging strategies of female elephant seals from Península Valdés, Patagonia, inferred from whisker stable isotope signatures of their pups' , Aquatic Mammals, vol. 45, no. 1 , pp. 1-13 , doi:10.1578/AM.45.1.2019.1 <http://dx.doi.org/10.1578/AM.45.1.2019.1>. seals foraging ecology habitat use neritic/oceanic foraging strategies stable isotopes individual specialization Article PeerReviewed 2019 ftunivtasmania https://doi.org/10.1578/AM.45.1.2019.1 2022-01-17T23:18:30Z The foraging strategies of gestating female elephant seals (Mirounga leonina) from Península Valdés, Patagonia, were assessed by analyzing the values of stable isotopes of carbon (C) and nitrogen (N) from whiskers of 60 weanlings as a proxy for maternal spatial niche utilization. The data were combined with isotopic values and at-sea satellite locations of juvenile seals and adult female satellite tracks to provide classifications of the likely foraging strategies of the mothers of the studied pups. Based on at-sea locations during the austral summer, females foraged in oceanic waters while juveniles foraged both in neritic and in oceanic habitats. Weanling isotopic values (n = 60 pups) ranged from -19.9 to -14.8‰ for C and from 10.6 to 18.9‰ for N. The degree of variation of spatial niche distribution exhibited individual patterns of habitat use over time and revealed significant intra-population differences. Ten percent of the individuals exhibited neritic maternal foraging (δ13C = -15.6 ± 0.5‰, δ15N = 17.3 ± 1.1‰) and high consistency, thus suggesting specialization (%CV δ13C values = 0.3 to 2.2), while 90% of the individuals exhibited oceanic maternal foraging (δ13C = -17.9 ± 0.7‰, δ15N = 12.4 ± 0.5). Additionally, oceanic maternal foraging could be further classified to distinguish broader individual variability: 58% were specialists (%CV = 0.03 to 2.2), 30% were intermediate specialists-generalists (%CV = 2.5 to 4.5), and 12% were generalists (%CV = 5.0 to 7.3). The prevailing strategy for females was oceanic foraging as exhibited by location at sea and the greater extent of oceanic habitats (88%) potentially available for foraging. At the population level, the existence of both alternate foraging strategies and high individual variability exhibited by gestating females in a high-quality foraging area such as the oceanic environment of the Argentine Basin may confer an ecological edge to these females to succeed in a less predictable (although fairly rich) environment, thus influencing population trends. Article in Journal/Newspaper Elephant Seals Mirounga leonina University of Tasmania: UTas ePrints Argentine Austral Patagonia Aquatic Mammals 45 1 1 13
institution Open Polar
collection University of Tasmania: UTas ePrints
op_collection_id ftunivtasmania
language unknown
topic seals
foraging ecology
habitat use
neritic/oceanic foraging strategies
stable isotopes
individual specialization
spellingShingle seals
foraging ecology
habitat use
neritic/oceanic foraging strategies
stable isotopes
individual specialization
Eder, EB
Muelbert, MMC
Hindell, MA
Davis, RW
Rodriguez, DH
Lewis, MN
Foraging strategies of female elephant seals from Península Valdés, Patagonia, inferred from whisker stable isotope signatures of their pups
topic_facet seals
foraging ecology
habitat use
neritic/oceanic foraging strategies
stable isotopes
individual specialization
description The foraging strategies of gestating female elephant seals (Mirounga leonina) from Península Valdés, Patagonia, were assessed by analyzing the values of stable isotopes of carbon (C) and nitrogen (N) from whiskers of 60 weanlings as a proxy for maternal spatial niche utilization. The data were combined with isotopic values and at-sea satellite locations of juvenile seals and adult female satellite tracks to provide classifications of the likely foraging strategies of the mothers of the studied pups. Based on at-sea locations during the austral summer, females foraged in oceanic waters while juveniles foraged both in neritic and in oceanic habitats. Weanling isotopic values (n = 60 pups) ranged from -19.9 to -14.8‰ for C and from 10.6 to 18.9‰ for N. The degree of variation of spatial niche distribution exhibited individual patterns of habitat use over time and revealed significant intra-population differences. Ten percent of the individuals exhibited neritic maternal foraging (δ13C = -15.6 ± 0.5‰, δ15N = 17.3 ± 1.1‰) and high consistency, thus suggesting specialization (%CV δ13C values = 0.3 to 2.2), while 90% of the individuals exhibited oceanic maternal foraging (δ13C = -17.9 ± 0.7‰, δ15N = 12.4 ± 0.5). Additionally, oceanic maternal foraging could be further classified to distinguish broader individual variability: 58% were specialists (%CV = 0.03 to 2.2), 30% were intermediate specialists-generalists (%CV = 2.5 to 4.5), and 12% were generalists (%CV = 5.0 to 7.3). The prevailing strategy for females was oceanic foraging as exhibited by location at sea and the greater extent of oceanic habitats (88%) potentially available for foraging. At the population level, the existence of both alternate foraging strategies and high individual variability exhibited by gestating females in a high-quality foraging area such as the oceanic environment of the Argentine Basin may confer an ecological edge to these females to succeed in a less predictable (although fairly rich) environment, thus influencing population trends.
format Article in Journal/Newspaper
author Eder, EB
Muelbert, MMC
Hindell, MA
Davis, RW
Rodriguez, DH
Lewis, MN
author_facet Eder, EB
Muelbert, MMC
Hindell, MA
Davis, RW
Rodriguez, DH
Lewis, MN
author_sort Eder, EB
title Foraging strategies of female elephant seals from Península Valdés, Patagonia, inferred from whisker stable isotope signatures of their pups
title_short Foraging strategies of female elephant seals from Península Valdés, Patagonia, inferred from whisker stable isotope signatures of their pups
title_full Foraging strategies of female elephant seals from Península Valdés, Patagonia, inferred from whisker stable isotope signatures of their pups
title_fullStr Foraging strategies of female elephant seals from Península Valdés, Patagonia, inferred from whisker stable isotope signatures of their pups
title_full_unstemmed Foraging strategies of female elephant seals from Península Valdés, Patagonia, inferred from whisker stable isotope signatures of their pups
title_sort foraging strategies of female elephant seals from península valdés, patagonia, inferred from whisker stable isotope signatures of their pups
publisher Western Illinois University Regional Center
publishDate 2019
url https://eprints.utas.edu.au/40032/
geographic Argentine
Austral
Patagonia
geographic_facet Argentine
Austral
Patagonia
genre Elephant Seals
Mirounga leonina
genre_facet Elephant Seals
Mirounga leonina
op_relation Eder, EB, Muelbert, MMC, Hindell, MA orcid:0000-0002-7823-7185 , Davis, RW, Rodriguez, DH and Lewis, MN 2019 , 'Foraging strategies of female elephant seals from Península Valdés, Patagonia, inferred from whisker stable isotope signatures of their pups' , Aquatic Mammals, vol. 45, no. 1 , pp. 1-13 , doi:10.1578/AM.45.1.2019.1 <http://dx.doi.org/10.1578/AM.45.1.2019.1>.
op_doi https://doi.org/10.1578/AM.45.1.2019.1
container_title Aquatic Mammals
container_volume 45
container_issue 1
container_start_page 1
op_container_end_page 13
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