Sexing Common Snipe (Gallinago gallinago) in the Field - is there any Simple Method?

There are a few methods used for sex determination in the Common Snipe. However, all proposed methods are based on data obtained from dead birds. The most important feature is the total length of the outermost tail feather. The performed analysis showed that the vane length was strongly correlated with the total length of this feather. It allowed to predict this measurement having only the vane length. Because the measurement procedure influences the vane length, new ranges of vane length typical for each sex are proposed. However, the analysis of the vane length distribution suggested that there were no two homogenous groups that would represent the two sexes. This supports the prediction that the total feather length should be used rather cautiously as a simple sex trait in the Common Snipe. Also the second trait based on the tail feather colour resulted in overestimation of the proportion of females.