Age and sex dimorphism in the Canary Blue Tit Cyanistes teneriffae teneriffae on the island of Tenerife, Canary Islands

Publication Type:Journal Article
Year of Publication:2010
Authors:García-del-Rey, E
Journal:Ostrich
Volume:81
Issue:1
Date Published:2010
ISBN Number:0030-6525
Keywords:Cyanistes, Cyanistes caeruleus, Cyanistes teneriffae, Fringillidae, Paridae, Parus caeruleus, Parus teneriffae, Serinus, Serinus canaria
Abstract:The Canary Blue Tit Cyanistes teneriffae has recently been split off from the Common Blue Tit Cyanistes caeruleus as a separate species. Live biometrics from across the entire distribution on the island of Tenerife (subspecies teneriffae teneriffae) are reported. Results suggest that first-year birds had similar bill shape to adults but differed in wing length, tarsus, tail and mass, being smaller on average. A high degree of sexual size dimorphism is reported, males being on average larger than females for wing length, bill length, bill depth and tarsus. A classification tree between the sexes showed that wing length and bill depth were the most important variables and correctly classified males in all occasions (i.e. male = wing length > 62.5 mm; bill depth > 3.7 mm, 100% correctly classified) but for practical sexing in the field it is recommended to use wing length as a reliable sexing criterion (wing length > 62.5 = male, 96% correctly classified). This high degree of sexual size dimorphism observed suggests a high sexual selection in the Canary Blue Tit.The Canary Blue Tit Cyanistes teneriffae has recently been split off from the Common Blue Tit Cyanistes caeruleus as a separate species. Live biometrics from across the entire distribution on the island of Tenerife (subspecies teneriffae teneriffae) are reported. Results suggest that first-year birds had similar bill shape to adults but differed in wing length, tarsus, tail and mass, being smaller on average. A high degree of sexual size dimorphism is reported, males being on average larger than females for wing length, bill length, bill depth and tarsus. A classification tree between the sexes showed that wing length and bill depth were the most important variables and correctly classified males in all occasions (i.e. male = wing length > 62.5 mm; bill depth > 3.7 mm, 100% correctly classified) but for practical sexing in the field it is recommended to use wing length as a reliable sexing criterion (wing length > 62.5 = male, 96% correctly classified). This high degree of sexual size dimorphism observed suggests a high sexual selection in the Canary Blue Tit.
URL:http://www.tandfonline.com/doi/abs/10.2989/00306525.2010.455819
Short Title:Ostrich
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