Leopard seal diets in a rapidly warming polar region vary by year, season, sex, and body size
BackgroundResolving the preferred prey items and dietary proportions of leopard seals is central to understanding food-web dynamics in the rapidly-warming Antarctic Peninsula region. Previous studies have identified a wide range of prey items; however, due to anecdotal or otherwise limited informati...
Main Authors: | , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
eScholarship, University of California
2020
|
Subjects: | |
Online Access: | https://escholarship.org/uc/item/0pp261rf |
id |
ftcdlib:oai:escholarship.org:ark:/13030/qt0pp261rf |
---|---|
record_format |
openpolar |
spelling |
ftcdlib:oai:escholarship.org:ark:/13030/qt0pp261rf 2023-11-05T03:36:05+01:00 Leopard seal diets in a rapidly warming polar region vary by year, season, sex, and body size Krause, Douglas J Goebel, Michael E Kurle, Carolyn M 32 2020-12-01 application/pdf https://escholarship.org/uc/item/0pp261rf unknown eScholarship, University of California qt0pp261rf https://escholarship.org/uc/item/0pp261rf public BMC Ecology and Evolution, vol 20, iss 1 Zoology Ecology Biological Sciences Prevention Animals Antarctic Regions Bayes Theorem Body Size Cold Climate Diet Female Male Predatory Behavior Seals Earless Seasons Stable isotope mixing model Apex predator Top down Prey shift Hydrurga leptonyx Climate change Animal-borne video Evolutionary Biology article 2020 ftcdlib 2023-10-09T18:05:59Z BackgroundResolving the preferred prey items and dietary proportions of leopard seals is central to understanding food-web dynamics in the rapidly-warming Antarctic Peninsula region. Previous studies have identified a wide range of prey items; however, due to anecdotal or otherwise limited information, leopard seal diets remain unresolved by seal sex, individual, body size, region, and season. Over the 2013, 2014, and 2017 field seasons we collected scat, tissue samples (red blood cells and plasma; n = 23) for stable isotope analyses, and previously-reported animal-borne video from 19 adult leopard seals foraging near mesopredator breeding colonies at Cape Shirreff, Livingston Island. We summarized a priori diet information from scat and video analysis and applied a three-isotope (δ13C, δ15N, δ34S), four-source (fish, fur seal, krill, penguin) Bayesian mixing model to examine temporal variability in both prey sources and leopard seal tissues.ResultsThe austral spring diets of males and females focused on Antarctic krill (31.7-38.0%), notothen fish (31.6-36.5%), and penguin (24.4-26.9%) and were consistent across all 3years. Several lines of evidence suggest the transition to summer foraging was distinct for males and females. Female diets transitioned rapidly to higher δ15N values (+2.1‰), indicating increased consumption of penguin (29.5-46.2%) and energy-dense Antarctic fur seal pup (21.3-37.6%).ConclusionsThe seasonal increase in leopard seal δ15N values, and thus fur seal in their diet, was predictably related to larger body size; it may also be forcing reductions to the largest Antarctic fur seal colony in the Antarctic Peninsula. Our ensemble sampling approach reduces historical biases in monitoring marine apex predator diets. Further, our results are necessary to best inform regional fisheries management planning. Article in Journal/Newspaper Antarc* Antarctic Antarctic Fur Seal Antarctic Krill Antarctic Peninsula Hydrurga leptonyx Leopard Seal Leopard Seals Livingston Island University of California: eScholarship |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Zoology Ecology Biological Sciences Prevention Animals Antarctic Regions Bayes Theorem Body Size Cold Climate Diet Female Male Predatory Behavior Seals Earless Seasons Stable isotope mixing model Apex predator Top down Prey shift Hydrurga leptonyx Climate change Animal-borne video Evolutionary Biology |
spellingShingle |
Zoology Ecology Biological Sciences Prevention Animals Antarctic Regions Bayes Theorem Body Size Cold Climate Diet Female Male Predatory Behavior Seals Earless Seasons Stable isotope mixing model Apex predator Top down Prey shift Hydrurga leptonyx Climate change Animal-borne video Evolutionary Biology Krause, Douglas J Goebel, Michael E Kurle, Carolyn M Leopard seal diets in a rapidly warming polar region vary by year, season, sex, and body size |
topic_facet |
Zoology Ecology Biological Sciences Prevention Animals Antarctic Regions Bayes Theorem Body Size Cold Climate Diet Female Male Predatory Behavior Seals Earless Seasons Stable isotope mixing model Apex predator Top down Prey shift Hydrurga leptonyx Climate change Animal-borne video Evolutionary Biology |
description |
BackgroundResolving the preferred prey items and dietary proportions of leopard seals is central to understanding food-web dynamics in the rapidly-warming Antarctic Peninsula region. Previous studies have identified a wide range of prey items; however, due to anecdotal or otherwise limited information, leopard seal diets remain unresolved by seal sex, individual, body size, region, and season. Over the 2013, 2014, and 2017 field seasons we collected scat, tissue samples (red blood cells and plasma; n = 23) for stable isotope analyses, and previously-reported animal-borne video from 19 adult leopard seals foraging near mesopredator breeding colonies at Cape Shirreff, Livingston Island. We summarized a priori diet information from scat and video analysis and applied a three-isotope (δ13C, δ15N, δ34S), four-source (fish, fur seal, krill, penguin) Bayesian mixing model to examine temporal variability in both prey sources and leopard seal tissues.ResultsThe austral spring diets of males and females focused on Antarctic krill (31.7-38.0%), notothen fish (31.6-36.5%), and penguin (24.4-26.9%) and were consistent across all 3years. Several lines of evidence suggest the transition to summer foraging was distinct for males and females. Female diets transitioned rapidly to higher δ15N values (+2.1‰), indicating increased consumption of penguin (29.5-46.2%) and energy-dense Antarctic fur seal pup (21.3-37.6%).ConclusionsThe seasonal increase in leopard seal δ15N values, and thus fur seal in their diet, was predictably related to larger body size; it may also be forcing reductions to the largest Antarctic fur seal colony in the Antarctic Peninsula. Our ensemble sampling approach reduces historical biases in monitoring marine apex predator diets. Further, our results are necessary to best inform regional fisheries management planning. |
format |
Article in Journal/Newspaper |
author |
Krause, Douglas J Goebel, Michael E Kurle, Carolyn M |
author_facet |
Krause, Douglas J Goebel, Michael E Kurle, Carolyn M |
author_sort |
Krause, Douglas J |
title |
Leopard seal diets in a rapidly warming polar region vary by year, season, sex, and body size |
title_short |
Leopard seal diets in a rapidly warming polar region vary by year, season, sex, and body size |
title_full |
Leopard seal diets in a rapidly warming polar region vary by year, season, sex, and body size |
title_fullStr |
Leopard seal diets in a rapidly warming polar region vary by year, season, sex, and body size |
title_full_unstemmed |
Leopard seal diets in a rapidly warming polar region vary by year, season, sex, and body size |
title_sort |
leopard seal diets in a rapidly warming polar region vary by year, season, sex, and body size |
publisher |
eScholarship, University of California |
publishDate |
2020 |
url |
https://escholarship.org/uc/item/0pp261rf |
op_coverage |
32 |
genre |
Antarc* Antarctic Antarctic Fur Seal Antarctic Krill Antarctic Peninsula Hydrurga leptonyx Leopard Seal Leopard Seals Livingston Island |
genre_facet |
Antarc* Antarctic Antarctic Fur Seal Antarctic Krill Antarctic Peninsula Hydrurga leptonyx Leopard Seal Leopard Seals Livingston Island |
op_source |
BMC Ecology and Evolution, vol 20, iss 1 |
op_relation |
qt0pp261rf https://escholarship.org/uc/item/0pp261rf |
op_rights |
public |
_version_ |
1781690783766675456 |