Specific of air survey at Kamchatka
  1. Very bad developed road net: Kamchatka is about 350 000 squere kilometres and the total extension of the roads is about 1300 kilometres, among which just 120 kilometres is covered by asphalt.
  2. Low density of human population which are concentrated in a small local settelments which are very far one from another.
  3. Landscape specifics: strongly billowy landscape, short mountain rivers, rocky sea coast.
  4. Features of SSE nestling on Kamchatka, where their nests are authentic less, than on a continental part of breeding area, and allocate in a dense part of crown
  5. Climate conditions
 Fig1. Location of the helicopter bases and main people settlements in Kamchatka

Fig4. Percent of recognised eagle nests at the model area in a different seasons		 The indicated features with necessity dictate:
usage of the helicopter for the surveys,
unacceptability of alternate methods of the surveys,
a very short and strictly limited time assigned for the surveys - prior to the beginning of the appearance of foliage on trees

Productivities of the winter surveys comes nearer to 100%, summer surveys made on the model splots have approximately 65% efficiency.