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OJVRTM
Online Journal of
Veterinary Research
Volume
5:69-83, 2001. Redacted 2018.
Sexing of parrots (P. senegalus) by discriminant analysis
A Zeffer
Göteborg University, Department of Zoology, Zoomorphology,
Box 463, SE 405 30 Göteborg, Sweden.
Email: anna.zeffer@zool.gu.se,
Phone: +46 31 773 3827, Fax: +46 31 41 67 29
ABSTRACT
Zeffer A., Sexing of parrots (P. senegalus) by
discriminant analysis. Onl J Vet
Res., 5:69-83, 2001. In many bird species, there is no obvious difference in the external
features of the sexes. This study investigates the problem of sex determination
in the Senegal Parrot (Poicephalus senegalus senegalus). The
work was conducted on 27 captive individuals, 13 females and 14 males. 32
morphological characters were measured, and 20 showed significant differences
between the sexes. The data were analysed with
discriminant analysis, a method that separates groups of individuals by
equations based on measured variables. A specialised
case of discriminant analysis was also used (jack knifing). The result shows
that in significantly separating characters, males are larger than females.
This size difference is especially visible in facial characters. The
discriminant analysis managed to separate 100 % of the individuals into the
correct groups using only two characters: bill height and distance between the
inner canthus. When using the jack-knifing method, 94,7
% of the individuals were correctly classified. This high percentage indicates
that the equation is a useable tool for quick determination of the sex in
Senegal Parrots.
KEY WORDS: Senegal Parrots; Poicephalus;
Psittaciformes;
morphology; sex determination; discriminant analysis
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