The birds of Pasvik / E. I. Khlebosolov, O. A. Makarova, O. A. Khlebosolova [et al. ; English transl. Nikita Chernetsov]. - Ryazan : Golosgubernii, 2007. - 175 с. : ил., портр.

Shorebirds Dynamics o f the numbers o f waders in Pasvik are controlled by ecological fac­ tors specific for each particular species. Analysis o f long-term data shows that popu­ lation numbers significantly vary on the annual basis. Numbers o f Wood Sandpipers, Common Greenshanks and Spotted Redshanks are related to water level in swamps. In high water years the numbers o f Wood Sandpipers decrease, and those of Common Greenshanks and Spotted Redshanks increase. In low water years the opposite trend is observed (Fig. 1.2, 1.3). The reason is that these three species forage at different depth. Therefore variation in water level in their breeding habitats influences their numbers. In 1999—2005, the numbers o f G reater Golden Plovers were consistently decreasing. The reason should be some conditions in wintering grounds or on the 1,2 1 1 , 0 - 0,8 0 , 6 - 0,4 - 0,2 0 Wood Sandpiper Common Greenshank Spotted Redshank Years Figure 1.2. Dynamics of numbers of the Wood Sandpiper, Common Greenshank, and Spotted Redshank at the Janiskoski study plot in 1999—2004. Water level 1999 2000 2003 2004 2001 Years Figure 1.3. Change of water level at the Janiskoski study plot in 1999—2004. 61