1. a Institute of Ecology of Vilnius University , Akademijos 2, LT-08412 , Vilnius-21 , Lithuania
2. b Kaišiadorys State Forest Enterprise , Miškininkų 1, LT-56161 , Kaišiadorys , Lithuania
3. c Lithuanian Ornithological Society , Naugarduko 47–3, LT-03208 , Vilnius-6 , Lithuania
4. d Lithuanian University of Agriculture, Faculty of Water and Land Management , Studentų 11, LT-53361 , Akademija , Lithuania
5. e State enterprise Forest Inventory and Management Institute , Pramonės 11a, LT-51327 , Kaunas , Lithuania