During vegetation seasons from 1992 to 1994 a settling of wooden breeding boxes for birds by the wasp Dolichovespula saxonica (FABR.) in typical forest habitats of Borecka Forest was observed. Interactions with birds, mammals and social insects were investigated, too. Reproduction; Reproductive behaviour; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Ecology; Competition; Habitat utilization; Land zones; Palaearctic region; Eurasia; Europe Sphecophaga vesparum (Ichneumonidae); Hymenopteran hosts; Dolichovespula saxonica; Parasite effect on host settling in bird nesting boxes; Poland; Borecka Forest; Hymenoptearn parasite effect on host settling in bird nesting boxes Dolichovespula saxonica (Vespidae); Breeding site; Hymenopteran parasites; Sphecophaga vesparum; Interspecific competition; Habitat colonization; Poland; Borecka Forest; Settling in bird nesting boxes, ecological significance none