Sex identification in the moorhen(Gallinula chloropus)by flow cytometry and morphometric analysis

Abstract

1999)Sex identification in the moorhen (Gallinula chloropus) by flow cytometry and morphometric analysisABSTRACT Sexing individuals in a population is important in many ecological and life-history studies. Since many bird species are monomorphic, non-invasive tools are necessary for sex determination. In this study we utilized flow cytometry to sex individuals in a moorhen population of northern Italy. By improving previous laboratory protocols, we were able to obtain clear and repeatable measures of DNA content from field blood samples. The per cent difference in nuclear content between male and female moorhens was among the highest values reported for birds. We also utilized a discriminant analysis of seven morphological measures to investigate whether birds can be sexed on the basis of biometry. Tarsus and foot lengths were the most influential variables in gender discrimination. However, only 13 females and 10 males (77%) were correctly sexed, while six females and two males were wrongly assigned. When juvenile moorhens were excluded the discriminant analysis correctly sexed 90% of the birds. Since morphometric comparisons with English moorhen populations showed that discriminant biometrical values are geographically different, and thus not useful as universal sexing tools, we recommend the use of the cytometry technique for sex determination.

Morphometric and genetic sexing in the Gough MoorhenGallinula comeri

“…Sexually monomorphic species present a challenge if sexing by behaviour is not possible and immediate results are required. Discriminant analysis using morphometrics has been used extensively for sex determination in many birds, including rails (Craig et al 1980, Cucco et al 1999, Eason et al 2001, Fuertes et al 2010. These studies revealed that sexing parameters may differ among closely related species and even among populations of the same species (Craig et al 1980, Millar et al 1996, Fuertes et al 2010.…”