American Bittern (Botaurus lentiginosus) Science Article 1
Biometrics, plumage and bare-part colour of 87 Great BitternsBotaurus stellarisfrom the UK,France, Italy, Poland and Belarus, of known sex (sexed by behaviour, DNA or dissection),were analysed to provide reliable sexing and ageing criteria for this little-known species,and to investigate geographical variation in biometrics. Four parameters were analysed: billlength, tarsus, wing length and body weight. We found little (though significant) geographicalvariation across Europe, but this was not clinal and we cannot exclude variation in measurementtechnique among observers. Males were significantly larger than females for allbiometric parameters: a discriminant function based on these parameters was able to sexcorrectly all individuals.
MARINA DMITRENOK et al., Ibis(2007),149, 37-44