Bird sex-typing using genetic markers


The Facility has identified markers for the genetic sexing of over 150 species of birds (Dawson 2005, Dawson et al. 2015, Dawson et al. 2016) and supported multiple studies involving bird sex-typing (30+ species, see Facility-supported Publications).


We have also developed new sex-typing markers:

Marker Z43B is able to sex most birds including those problematic to sex with CHD-based markers (Dawson et al. 2016).

Marker Z37B is suitable for sex-typing birds from degraded samples and samples of low quantity (Dawson et al. 2015).

Other new bird sex-typing markers will be published in the near future.

We have assessed the utility of two commonly used published sex-typing markers (Griffiths et al. (1998: P2/P8) and Fridolfsson and Ellegren (1999: 2550F/2718R)) and created a web-based database of the most suitable methods to sex-type different species (see right-hand link, Dawson 2005).

In addition to the species we have sex-typed here at Sheffield, we have collected data which was very kindly contributed from many researchers and added all data, along with the published original data (Griffiths et al. (1998) and Fridolfsson and Ellegren (1999) to a database which can be downloaded from this page.

The "NBAF-S Bird sexing database" (Dawson 2005) includes a list of ~130 bird species (non-passerines and passerines) which have been sexed and the sexing primer sets which were used. The database and details of the technical methods/ protocols used are provided in the document on the right-hand link.

Potential sources of error when sex-typing birds

We would also like to draw attention to the potential sources of error in misinterpreting molecular sexing data caused by the presence of Z allele polymorphism, such as that identified in auklets (Dawson et al. 2001) and other species (Dawson et al. 2015).


Bruford MW, Hanotte O, Brookfield JFY, Burke T (1998) Multilocus and single-locus DNA fingerprinting. In: Molecular Genetic Analysis of Populations: A Practical Approach, 2nd edition, (ed. Hoelzel AR), pp. 287-336. IRL Press, Oxford.

Dawson DA (2005) NBAF-S Bird sexing database: Identifying suitable sex-typing markers for over 100 bird species.

Dawson DA, Brekke P, dos Remedios N, Horsburgh GJ (2015) A marker suitable for sex-typing birds from degraded samples. Conservation Genetics Resources, In press [Open Access].

Dawson DA, Darby S, Hunter FM, Krupa AP, Jones IL and Burke T (2001) A critique of CHD-based molecular sexing protocols illustrated by a Z-chromosome polymorphism detected in auklets (Aves: Alcidae, Laridae). Molecular Ecology Notes, 1, 201-204.

Dawson DA, dos Remedios N, Horsburgh GJ (2016) A new marker based on the avian spindlin gene that is able to sex most birds, including species problematic to sex with CHD markers. Zoo Biology. In press. [Open Access]

Fridolfsson AK and Ellegren H (1999) A simple and universal method for molecular sexing of non-ratite birds. Journal of Avian Biology, 30, 116-121.

Griffiths R, Double MC, Orr K and Dawson RJG (1998) A DNA test to sex most birds. Molecular Ecology, 7, 1071-1075.