Data on the locations and behavior of breeding birds obtained by mapping (registrations made during census visits) along a fixed route (permanent transect) in mixed spruce-small-leaved forest of different ages (Russia, Moscow region, border of Naro-Fominsk and Podolsk districts)

The dataset describes the spatial distribution of registrations and behavior of 66 bird species censused by the territory mapping method during the breeding period along a fixed route (permanent transect) in mixed spruce-small-leaved and spruce forests of different ages (from 30 to 110 years).The route length was 2700 m, with a maximum elevation difference of about 10 m. Geographic coordinates of the furthest points of the route were 55°26′51.7″ N, 37°09′37.6″ E and 55°28′16.5″ N, 37°09′02.1″ E. For five years (1990, 1991, 1992, 1994 and 1998), from early April to mid-July, birds were mapped along the route.

The mapping visits were made regularly at intervals of 4-6 days.