Some phenotypic features of the common crane Grus grus

The long-term field observations in Russia and Ukraine, the Nursery of rare crane species (Oka State Nature Biosphere Reserve) and examination of the museum collections allowed us to make the first steps in analysis of individual and geographic variation of the common crane Grus grus (L.) (Ilyashenko et al. 2008). Comparison of coloration of the head, the upper neck, the “tail” (tertiaries and their coverts), egg measurements (body mass) and a number of indices of outer morphology in 402 alive, collected, and photographed individuals provided material for description of some phenotypic peculiarities of birds within the range of the species. Comparison of coloration of the top of the head in 251 G. g. grus and 151 G. g. lilfordi allowed proposing an “operational” classification of the types of the “crown” and demonstrating differences in their frequencies in the European and Asian parts of the range. For example, black “crowns” were recorded only in 2.4% of European cranes, but in 9.5% of Asian. Correlation between the length of the “necktie” and the nape wedge in European cranes was revealed. The iris is brown in downy chicks, but by the time of formation of pre-migration congregations (when the young birds are 3 to 4 months old) is pigmentation changes in most of the cranes. Iris coloration reaches its definitive state by the end of the second main moult that terminated by late October in the Oka Nature Reserve (the age of 16-18 months), and no changes occur afterwards. In adult G. g. grus, yellow iris is significantly less frequent, whereas red iris is more frequent than in G. g. lilfordi ( φ test: P