Sexual dimorphism and determination of sex by morphometrics in Blue-fronted Amazons (Amazona aestiva)

On current knowledge, it has not been possible to determine the sex of Blue-fronted Amazons (Amazona aestiva) in the hand, as males and females were thought not to differ in the colour of plumage or size. We used discriminant function analysis to develop equations for determining the sex of Blue-fro...

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Autores principales: Berkunsky, I., Mahler, B., Reboreda, J.C.
Formato: JOUR
Materias:
Amazona aestiva xanthopteryx
Discriminant analysis
Sexual dichromatism
bird
body size
discriminant analysis
DNA
genetic analysis
morphometry
plumage
population viability analysis
sex determination
sexual dimorphism
Argentina
South America
Amazona aestiva
Aves
Psittacidae
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_01584197_v109_n3_p192_Berkunsky
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id todo:paper_01584197_v109_n3_p192_Berkunsky
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spelling todo:paper_01584197_v109_n3_p192_Berkunsky2023-10-03T15:01:10Z Sexual dimorphism and determination of sex by morphometrics in Blue-fronted Amazons (Amazona aestiva) Berkunsky, I. Mahler, B. Reboreda, J.C. Amazona aestiva xanthopteryx Discriminant analysis Sexual dichromatism bird body size discriminant analysis DNA genetic analysis morphometry plumage population viability analysis sex determination sexual dimorphism Argentina South America Amazona aestiva Amazona aestiva xanthopteryx Aves Psittacidae On current knowledge, it has not been possible to determine the sex of Blue-fronted Amazons (Amazona aestiva) in the hand, as males and females were thought not to differ in the colour of plumage or size. We used discriminant function analysis to develop equations for determining the sex of Blue-fronted Amazons using in-hand measurements. We took seven measurements of size and one measure of plumage colour (percentage of yellow on the head) from 202 birds in north-western Argentina. The sex of each individual was determined using DNA-based genetic techniques. For all size measurements, males averaged larger than females. Males also had a higher percentage of yellow plumage on the head than females. The percentage of yellow plumage (64%) and body mass (12%) had the highest degree of dimorphism, but also showed high within-sex coefficients of variation, correctly classifying 73% and 72% of the individuals respectively. Although bill-depth had a low degree of dimorphism (7%), it had the lowest coefficient of variation (4%) resulting in the most accurate single-measurement for sexing this species (80% of the individuals). A cross validation process revealed that a discriminant function including three measurements (bill-depth, tibial length and head-width) was more accurate and reliable for determination of sex than single measurements, classifying correctly85%of the individuals. Our results showthat Blue-fronted Amazons are sexually dimorphic for most characteristics of body size and show sexual dichromatism in the colour of the plumage of the head, which allows determination of sex of individuals by morphological variables that can be easily measured in the field. © Royal Australasian Ornithologists Union 2009. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_01584197_v109_n3_p192_Berkunsky
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Amazona aestiva xanthopteryx
Discriminant analysis
Sexual dichromatism
bird
body size
discriminant analysis
DNA
genetic analysis
morphometry
plumage
population viability analysis
sex determination
sexual dimorphism
Argentina
South America
Amazona aestiva
Amazona aestiva xanthopteryx
Aves
Psittacidae
spellingShingle Amazona aestiva xanthopteryx
Discriminant analysis
Sexual dichromatism
bird
body size
discriminant analysis
DNA
genetic analysis
morphometry
plumage
population viability analysis
sex determination
sexual dimorphism
Argentina
South America
Amazona aestiva
Amazona aestiva xanthopteryx
Aves
Psittacidae
Berkunsky, I.
Mahler, B.
Reboreda, J.C.
Sexual dimorphism and determination of sex by morphometrics in Blue-fronted Amazons (Amazona aestiva)
topic_facet Amazona aestiva xanthopteryx
Discriminant analysis
Sexual dichromatism
bird
body size
discriminant analysis
DNA
genetic analysis
morphometry
plumage
population viability analysis
sex determination
sexual dimorphism
Argentina
South America
Amazona aestiva
Amazona aestiva xanthopteryx
Aves
Psittacidae
description On current knowledge, it has not been possible to determine the sex of Blue-fronted Amazons (Amazona aestiva) in the hand, as males and females were thought not to differ in the colour of plumage or size. We used discriminant function analysis to develop equations for determining the sex of Blue-fronted Amazons using in-hand measurements. We took seven measurements of size and one measure of plumage colour (percentage of yellow on the head) from 202 birds in north-western Argentina. The sex of each individual was determined using DNA-based genetic techniques. For all size measurements, males averaged larger than females. Males also had a higher percentage of yellow plumage on the head than females. The percentage of yellow plumage (64%) and body mass (12%) had the highest degree of dimorphism, but also showed high within-sex coefficients of variation, correctly classifying 73% and 72% of the individuals respectively. Although bill-depth had a low degree of dimorphism (7%), it had the lowest coefficient of variation (4%) resulting in the most accurate single-measurement for sexing this species (80% of the individuals). A cross validation process revealed that a discriminant function including three measurements (bill-depth, tibial length and head-width) was more accurate and reliable for determination of sex than single measurements, classifying correctly85%of the individuals. Our results showthat Blue-fronted Amazons are sexually dimorphic for most characteristics of body size and show sexual dichromatism in the colour of the plumage of the head, which allows determination of sex of individuals by morphological variables that can be easily measured in the field. © Royal Australasian Ornithologists Union 2009.
format JOUR
author Berkunsky, I.
Mahler, B.
Reboreda, J.C.
author_facet Berkunsky, I.
Mahler, B.
Reboreda, J.C.
author_sort Berkunsky, I.
title Sexual dimorphism and determination of sex by morphometrics in Blue-fronted Amazons (Amazona aestiva)
title_short Sexual dimorphism and determination of sex by morphometrics in Blue-fronted Amazons (Amazona aestiva)
title_full Sexual dimorphism and determination of sex by morphometrics in Blue-fronted Amazons (Amazona aestiva)
title_fullStr Sexual dimorphism and determination of sex by morphometrics in Blue-fronted Amazons (Amazona aestiva)
title_full_unstemmed Sexual dimorphism and determination of sex by morphometrics in Blue-fronted Amazons (Amazona aestiva)
title_sort sexual dimorphism and determination of sex by morphometrics in blue-fronted amazons (amazona aestiva)
url http://hdl.handle.net/20.500.12110/paper_01584197_v109_n3_p192_Berkunsky
work_keys_str_mv AT berkunskyi sexualdimorphismanddeterminationofsexbymorphometricsinbluefrontedamazonsamazonaaestiva
AT mahlerb sexualdimorphismanddeterminationofsexbymorphometricsinbluefrontedamazonsamazonaaestiva
AT reboredajc sexualdimorphismanddeterminationofsexbymorphometricsinbluefrontedamazonsamazonaaestiva
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