Sessagio di due specie monocromatiche . Confronto morfometrico e analisi dela distribuzione.

Sexing of two monochromatic species. Morphometrical comparison and temporal distribution analysis during migrations We analysed morphometric characteristics and blood samples of 163 Garden Warblers Sylvia borin during the post-breeding migration and of 96 Robins Erithacus rubecula in various periods of the year; the aim was to find the distribution between males and females and to find relations between sex and some morphometric parameters. Birds were caught in two birding stations in Friuli Venezia Giulia from 2007 to 2009. We founded significative correlation between the length of wings and sex; for the Robin species this relation was very strong and the interval of measures of the total wing length, obtained from the sex determination, seems to be useful for distinguish males from females.