. 13, 4

  .  13,  4

! , .

6. , . , , .

, . , .

, . , . , .

?

. .

1 6 . , 6 . : .

. , -

. , .

RSPB, ThE LodqE, SamIv, l?(clloilsl-ii[ SCI 9 2DL, UK

wwav.RSpb.orcj.uk H/.W.^'

?
?