Sex-Specific Growth in the Imperial Cormorant (Phalacrocorax atriceps): When Does Dimorphism Arise?
Cormorants and shags (Phalacrocoracidae) are sexually monomorphic in plumage but dimorphic in size with males larger and heavier than females. Such size dimorphism has been capitalized upon for several species in the family to sex adults by using discriminant analysis applied on the morphometric mea...
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ftconicet:oai:ri.conicet.gov.ar:11336/64787 2023-10-09T21:55:15+02:00 Sex-Specific Growth in the Imperial Cormorant (Phalacrocorax atriceps): When Does Dimorphism Arise? Svagelj, Walter Sergio Quintana, Flavio Roberto application/pdf http://hdl.handle.net/11336/64787 eng eng Waterbird Society info:eu-repo/semantics/altIdentifier/url/http://www.bioone.org/doi/10.1675/063.040.0207 info:eu-repo/semantics/altIdentifier/doi/10.1675/063.040.0207 http://hdl.handle.net/11336/64787 Svagelj, Walter Sergio; Quintana, Flavio Roberto; Sex-Specific Growth in the Imperial Cormorant (Phalacrocorax atriceps): When Does Dimorphism Arise?; Waterbird Society; Waterbirds; 40; 2; 6-2017; 154-161 1524-4695 1938-5390 CONICET Digital CONICET info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ CORMORANTS DISCRIMINANT ANALYSIS NONLINEAR MIXED-EFFECT MODELS RICHARDS GROWTH MODEL SEXUAL SIZE DIMORPHISM https://purl.org/becyt/ford/1.6 https://purl.org/becyt/ford/1 info:eu-repo/semantics/article info:ar-repo/semantics/artículo info:eu-repo/semantics/publishedVersion ftconicet https://doi.org/10.1675/063.040.0207 2023-09-24T19:57:58Z Cormorants and shags (Phalacrocoracidae) are sexually monomorphic in plumage but dimorphic in size with males larger and heavier than females. Such size dimorphism has been capitalized upon for several species in the family to sex adults by using discriminant analysis applied on the morphometric measurements. Despite that, few studies have analyzed the development of sexual size dimorphism during chick growth. In this study, sexspecific growth was assessed in chicks of the Imperial Cormorant (Phalacrocorax atriceps) by analyzing the development of body mass, bill length, head length, tarsus length and wing length measured on 80 chicks sexed by DNA-based technics. Fieldwork was performed during the 2004 breeding season at Punta León, Patagonia, Argentina. In addition, discriminant analyses were performed to obtain functions to determine the sex of fledglings. Males had higher asymptotic values and growth rates than females for all measurements considered, even though the arising of dimorphism varied among morphometric characteristics (10-40 days). Discriminant functions to determine the sex of chicks at 30, 35 and 40 days of age were obtained. All functions included tarsus length and head length as variables, correctly classifying 88-94% of chicks. Our findings show the Imperial Cormorant to be an interesting model for evaluating the potential consequences of sexual size dimorphism on chick survival and fledging condition depending on brood sex composition. Fil: Svagelj, Walter Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina Article in Journal/Newspaper Phalacrocorax atriceps CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas) Patagonia Argentina Waterbirds 40 2 154 161 |
institution |
Open Polar |
collection |
CONICET Digital (Consejo Nacional de Investigaciones Científicas y Técnicas) |
op_collection_id |
ftconicet |
language |
English |
topic |
CORMORANTS DISCRIMINANT ANALYSIS NONLINEAR MIXED-EFFECT MODELS RICHARDS GROWTH MODEL SEXUAL SIZE DIMORPHISM https://purl.org/becyt/ford/1.6 https://purl.org/becyt/ford/1 |
spellingShingle |
CORMORANTS DISCRIMINANT ANALYSIS NONLINEAR MIXED-EFFECT MODELS RICHARDS GROWTH MODEL SEXUAL SIZE DIMORPHISM https://purl.org/becyt/ford/1.6 https://purl.org/becyt/ford/1 Svagelj, Walter Sergio Quintana, Flavio Roberto Sex-Specific Growth in the Imperial Cormorant (Phalacrocorax atriceps): When Does Dimorphism Arise? |
topic_facet |
CORMORANTS DISCRIMINANT ANALYSIS NONLINEAR MIXED-EFFECT MODELS RICHARDS GROWTH MODEL SEXUAL SIZE DIMORPHISM https://purl.org/becyt/ford/1.6 https://purl.org/becyt/ford/1 |
description |
Cormorants and shags (Phalacrocoracidae) are sexually monomorphic in plumage but dimorphic in size with males larger and heavier than females. Such size dimorphism has been capitalized upon for several species in the family to sex adults by using discriminant analysis applied on the morphometric measurements. Despite that, few studies have analyzed the development of sexual size dimorphism during chick growth. In this study, sexspecific growth was assessed in chicks of the Imperial Cormorant (Phalacrocorax atriceps) by analyzing the development of body mass, bill length, head length, tarsus length and wing length measured on 80 chicks sexed by DNA-based technics. Fieldwork was performed during the 2004 breeding season at Punta León, Patagonia, Argentina. In addition, discriminant analyses were performed to obtain functions to determine the sex of fledglings. Males had higher asymptotic values and growth rates than females for all measurements considered, even though the arising of dimorphism varied among morphometric characteristics (10-40 days). Discriminant functions to determine the sex of chicks at 30, 35 and 40 days of age were obtained. All functions included tarsus length and head length as variables, correctly classifying 88-94% of chicks. Our findings show the Imperial Cormorant to be an interesting model for evaluating the potential consequences of sexual size dimorphism on chick survival and fledging condition depending on brood sex composition. Fil: Svagelj, Walter Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Quintana, Flavio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina |
format |
Article in Journal/Newspaper |
author |
Svagelj, Walter Sergio Quintana, Flavio Roberto |
author_facet |
Svagelj, Walter Sergio Quintana, Flavio Roberto |
author_sort |
Svagelj, Walter Sergio |
title |
Sex-Specific Growth in the Imperial Cormorant (Phalacrocorax atriceps): When Does Dimorphism Arise? |
title_short |
Sex-Specific Growth in the Imperial Cormorant (Phalacrocorax atriceps): When Does Dimorphism Arise? |
title_full |
Sex-Specific Growth in the Imperial Cormorant (Phalacrocorax atriceps): When Does Dimorphism Arise? |
title_fullStr |
Sex-Specific Growth in the Imperial Cormorant (Phalacrocorax atriceps): When Does Dimorphism Arise? |
title_full_unstemmed |
Sex-Specific Growth in the Imperial Cormorant (Phalacrocorax atriceps): When Does Dimorphism Arise? |
title_sort |
sex-specific growth in the imperial cormorant (phalacrocorax atriceps): when does dimorphism arise? |
publisher |
Waterbird Society |
url |
http://hdl.handle.net/11336/64787 |
geographic |
Patagonia Argentina |
geographic_facet |
Patagonia Argentina |
genre |
Phalacrocorax atriceps |
genre_facet |
Phalacrocorax atriceps |
op_relation |
info:eu-repo/semantics/altIdentifier/url/http://www.bioone.org/doi/10.1675/063.040.0207 info:eu-repo/semantics/altIdentifier/doi/10.1675/063.040.0207 http://hdl.handle.net/11336/64787 Svagelj, Walter Sergio; Quintana, Flavio Roberto; Sex-Specific Growth in the Imperial Cormorant (Phalacrocorax atriceps): When Does Dimorphism Arise?; Waterbird Society; Waterbirds; 40; 2; 6-2017; 154-161 1524-4695 1938-5390 CONICET Digital CONICET |
op_rights |
info:eu-repo/semantics/openAccess https://creativecommons.org/licenses/by-nc-sa/2.5/ar/ |
op_doi |
https://doi.org/10.1675/063.040.0207 |
container_title |
Waterbirds |
container_volume |
40 |
container_issue |
2 |
container_start_page |
154 |
op_container_end_page |
161 |
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1779319105263763456 |