Summary
Until recently, the eastern boundary of the breeding range of the saker (Falco cherrug, J.E. Gray, 1834) was drawn through Transbaikalia and the Great Khingan mountain range (Stepanyan, 2003). However, since 1995, these birds have been recorded in the southwestern Primorye (Glushchenko and Kurinnyi, 2000). In 2001–2002, this species was found nesting here (Kurdyukov, 2002). Further records of the saker in different parts of the southern half of Primorye have become more or less regular, and some birds were recorded throughout the year (Shokhrin, 2005, 2007; Nechayev and Gamova, 2009; Glushchenko et al., 2012; Shokhrin et al., 2012).
In the northern part of Sakhalin (the Okha isthmus between Kolendo and Tropto bays), a flying bird resembling the saker in shape and color was observed on October 9, 2010. On October 10, 2009, the same bird was met perched and was sufficiently well seen in the binoculars and photographed. Even with a satisfactory quality of the resulting image, it was identified as the saker. The correctness of identification was confirmed by V.A. Nechaev and Yu.N. Glushchenko. This case should be regarded as an occasional vagrancy. The bird was encountered in Siberian dwarf pine thickets interspersed with waterlogged areas covered with wild rosemary and berries (crowberry, cloudberry, cowberry, blueberry, and cranberry). At this time, this area abounded in Chipmunks Tamias sibiricus, Nutcracker Nucifraga caryocatactes, and representatives of various passage shorebirds and waterfowl.