Prioksko-Terrasny Nature Reserve covering 4945 ha, 134 species of birds from 14 orders (Ciconiiformes, Anseriformes, Falconiformes, Galliformes, Gruiformes, Charadriiformes, Columbiformes, Cuculiformes, Strigiformes, Caprimulgiformes, Apodiformes, Coraciiformes, Piciformes, Passeriformes) had been registered by 1991. Later 5 more species were observed here. Thus, by the present time, the list of species of birds registered in the Reserve numbers 139 species. About 55% from them are Passerines. Most of birds of the Reserve belong to migratory breeding species or to nomadic breeding species. Some species are vagrants in the Reserve and in the Moscow Region (nutcracker Nicifraga caryocatactes (L.), etc.). Birds, nesting in central parts of Russia
Dusky crag martin species are members of the swallow family of birds, and are classed as members of the subfamily Hirundininae which comprises all swallows and martins except the very distinctive river martins. DNA studies suggest that there are three major groupings within the Hirundininae, broadly correlating with the type of nest built. The groups are the "core martins" including burrowing species like the sand martin, the "nest-adopters", which are birds like the tree swallow that utilise natural cavities, and the "mud nest builders". The "Ptyonoprogne" species construct an open mud nest and therefore belong to the latter group; "Hirundo" species also build