PISMENNYI K, VATRASEVICH R. 2007-2011. Mizhrichynskyi Park. Chernihiv Region

Photographing the same adult male Short-toed Eagle in the nature is an example of possible way to recognise individuals from one breeding season to another by the moulting of the biggest 14 wing feathers (4th-10th primaries); we call it “passive marking”. For comparing different photos we recommend to open images in new tabs or windows of your browser and then to switch between them.

So, from 02.IV.2011 to 18.IX.2011, i.e. from the arrival to the departure of the Short-toed Eagle, 7 of the biggest 14 primaries (R5, R6, R8, R10 and L4, L7, L9) have been replaced by new ones. At the same time 7 others (R4, R7, R9 and L5, L6, L8, L10) haven’t been. And 4 of the last ones (R4, R7 and L5, L8) were in the moulting process in August, 2010. According to discrete observations since 2007 moulting of 2 feathers (L5, L6) hasn’t completely corresponded to the two-year cycle, whereas moulting of 2 others (R5, R6) has.