Biometrical Differentiation of the Common Snipe (Gallinago gallinago) Migrating in Autumn Through North-Eastern Poland

The Common Snipe is a medium-sized wader with a broad range of distribution. The analysis of recoveries shows that most of Common Snipes migrating through the southern Baltic come from Scandinavia, Baltic countries and north-western and western Russia. In this paper differentiation in the biometrics of Common Snipes migrating through north-eastern Poland was described. The data were collected at two ringing stations in north-eastern Poland. No significant differences were found between biometrical parameters from these two ringing sites. The obtained results are similar to the ones from the Gulf of Gdańsk. Mean values of particular measurements and body mass of adult and juvenile birds did not differ significantly. There was no significant biometrical variance among juvenile birds between three analysed half month periods as well as between 5 years of study except for the seasonal differences in the mean value of tarsus with toe measurement. The mean values of measurements taken from the birds studied in this work are similar to the results obtained for the Gulf of Gdansk region, and higher than in the places located more inland (southern and eastern Poland). It might be caused by differences in the biometrical values among different populations. Low values of the body mass are characteristic for Common Snipes staying in places with different habitat conditions, which shows that this species migrates in autumn with very small energetic reserves, what is typical for strategy minimising energetic expenses during migration.