Sexual and geographic dimorphism in northern rockhopper penguins breeding in the South Atlantic Ocean
The Endangered northern rockhopper penguin Eudyptes moseleyi, like all penguins, is monomorphic, making sex determination of individuals in the field challenging. We examined the degree of sexual size dimorphism of adult birds across the species’ breeding range in the Atlantic Ocean and developed di...
Published in: | Endangered Species Research |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2019
|
Subjects: | |
Online Access: | https://pure.uhi.ac.uk/en/publications/9eda50da-b7a6-48bf-a239-0458eb669766 https://doi.org/10.3354/esr00970 https://pureadmin.uhi.ac.uk/ws/files/3786359/2019_Steinfuth_et_al_NRPE_dimorphism.pdf http://www.int-res.com/articles/suppl/n039p293_supp.xlsx http://www.mendeley.com/research/sexual-geographic-dimorphism-northern-rockhopper-penguins-breeding-south-atlantic-ocean |
id |
ftuhipublicatio:oai:pure.atira.dk:publications/9eda50da-b7a6-48bf-a239-0458eb669766 |
---|---|
record_format |
openpolar |
spelling |
ftuhipublicatio:oai:pure.atira.dk:publications/9eda50da-b7a6-48bf-a239-0458eb669766 2024-06-23T07:56:27+00:00 Sexual and geographic dimorphism in northern rockhopper penguins breeding in the South Atlantic Ocean Steinfurth, A Booth, JM White, J Bond, AL McQuaid, CD 2019-08-22 application/pdf https://pure.uhi.ac.uk/en/publications/9eda50da-b7a6-48bf-a239-0458eb669766 https://doi.org/10.3354/esr00970 https://pureadmin.uhi.ac.uk/ws/files/3786359/2019_Steinfuth_et_al_NRPE_dimorphism.pdf http://www.int-res.com/articles/suppl/n039p293_supp.xlsx http://www.mendeley.com/research/sexual-geographic-dimorphism-northern-rockhopper-penguins-breeding-south-atlantic-ocean eng eng https://pure.uhi.ac.uk/en/publications/9eda50da-b7a6-48bf-a239-0458eb669766 info:eu-repo/semantics/openAccess Steinfurth , A , Booth , JM , White , J , Bond , AL & McQuaid , CD 2019 , ' Sexual and geographic dimorphism in northern rockhopper penguins breeding in the South Atlantic Ocean ' , Endangered Species Research , vol. 39 , pp. 293-302 . https://doi.org/10.3354/esr00970 article 2019 ftuhipublicatio https://doi.org/10.3354/esr00970 2024-05-27T23:56:27Z The Endangered northern rockhopper penguin Eudyptes moseleyi, like all penguins, is monomorphic, making sex determination of individuals in the field challenging. We examined the degree of sexual size dimorphism of adult birds across the species’ breeding range in the Atlantic Ocean and developed discriminant functions (DF) to predict individuals’ sex using morphometric measurements. We found significant site-specific differences in both bill length and bill depth, with males being the larger sex on each island. Across all islands, bill length contributed 78% to dissimilarity between sexes. Penguins on Gough Island had significantly longer bills, whilst those from Tristan da Cunha had the deepest. Island-specific DFs correctly classified 82-94% of individuals, and all functions performed significantly better than chance. The model for Nightingale Island correctly classified the greatest proportion of individuals (94-95%), while that for Tristan da Cunha performed the poorest (80-82%). A discriminant function derived from all sites accurately sexed 86-88% of northern rockhopper penguins achieving similar accuracy to island-specific functions. While molecular techniques conclusively determine an individual’s sex, morphometric measurements can provide a reliable estimate with close to 90% accuracy using a method that is less invasive and requires little technical expertise. Sexing is an important tool for meaningful interpretation of ecological data. Consideration of sex-specific differences in future studies will aid investigation of a potential sex-dependent vulnerability in this Endangered species. Article in Journal/Newspaper Rockhopper penguin South Atlantic Ocean University of the Highlands and Islands: Research Database of UHI Gough ENVELOPE(159.367,159.367,-81.633,-81.633) Tristan ENVELOPE(140.900,140.900,-66.735,-66.735) Endangered Species Research 39 293 302 |
institution |
Open Polar |
collection |
University of the Highlands and Islands: Research Database of UHI |
op_collection_id |
ftuhipublicatio |
language |
English |
description |
The Endangered northern rockhopper penguin Eudyptes moseleyi, like all penguins, is monomorphic, making sex determination of individuals in the field challenging. We examined the degree of sexual size dimorphism of adult birds across the species’ breeding range in the Atlantic Ocean and developed discriminant functions (DF) to predict individuals’ sex using morphometric measurements. We found significant site-specific differences in both bill length and bill depth, with males being the larger sex on each island. Across all islands, bill length contributed 78% to dissimilarity between sexes. Penguins on Gough Island had significantly longer bills, whilst those from Tristan da Cunha had the deepest. Island-specific DFs correctly classified 82-94% of individuals, and all functions performed significantly better than chance. The model for Nightingale Island correctly classified the greatest proportion of individuals (94-95%), while that for Tristan da Cunha performed the poorest (80-82%). A discriminant function derived from all sites accurately sexed 86-88% of northern rockhopper penguins achieving similar accuracy to island-specific functions. While molecular techniques conclusively determine an individual’s sex, morphometric measurements can provide a reliable estimate with close to 90% accuracy using a method that is less invasive and requires little technical expertise. Sexing is an important tool for meaningful interpretation of ecological data. Consideration of sex-specific differences in future studies will aid investigation of a potential sex-dependent vulnerability in this Endangered species. |
format |
Article in Journal/Newspaper |
author |
Steinfurth, A Booth, JM White, J Bond, AL McQuaid, CD |
spellingShingle |
Steinfurth, A Booth, JM White, J Bond, AL McQuaid, CD Sexual and geographic dimorphism in northern rockhopper penguins breeding in the South Atlantic Ocean |
author_facet |
Steinfurth, A Booth, JM White, J Bond, AL McQuaid, CD |
author_sort |
Steinfurth, A |
title |
Sexual and geographic dimorphism in northern rockhopper penguins breeding in the South Atlantic Ocean |
title_short |
Sexual and geographic dimorphism in northern rockhopper penguins breeding in the South Atlantic Ocean |
title_full |
Sexual and geographic dimorphism in northern rockhopper penguins breeding in the South Atlantic Ocean |
title_fullStr |
Sexual and geographic dimorphism in northern rockhopper penguins breeding in the South Atlantic Ocean |
title_full_unstemmed |
Sexual and geographic dimorphism in northern rockhopper penguins breeding in the South Atlantic Ocean |
title_sort |
sexual and geographic dimorphism in northern rockhopper penguins breeding in the south atlantic ocean |
publishDate |
2019 |
url |
https://pure.uhi.ac.uk/en/publications/9eda50da-b7a6-48bf-a239-0458eb669766 https://doi.org/10.3354/esr00970 https://pureadmin.uhi.ac.uk/ws/files/3786359/2019_Steinfuth_et_al_NRPE_dimorphism.pdf http://www.int-res.com/articles/suppl/n039p293_supp.xlsx http://www.mendeley.com/research/sexual-geographic-dimorphism-northern-rockhopper-penguins-breeding-south-atlantic-ocean |
long_lat |
ENVELOPE(159.367,159.367,-81.633,-81.633) ENVELOPE(140.900,140.900,-66.735,-66.735) |
geographic |
Gough Tristan |
geographic_facet |
Gough Tristan |
genre |
Rockhopper penguin South Atlantic Ocean |
genre_facet |
Rockhopper penguin South Atlantic Ocean |
op_source |
Steinfurth , A , Booth , JM , White , J , Bond , AL & McQuaid , CD 2019 , ' Sexual and geographic dimorphism in northern rockhopper penguins breeding in the South Atlantic Ocean ' , Endangered Species Research , vol. 39 , pp. 293-302 . https://doi.org/10.3354/esr00970 |
op_relation |
https://pure.uhi.ac.uk/en/publications/9eda50da-b7a6-48bf-a239-0458eb669766 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.3354/esr00970 |
container_title |
Endangered Species Research |
container_volume |
39 |
container_start_page |
293 |
op_container_end_page |
302 |
_version_ |
1802649538915205120 |