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
Gleaning (birds) behavior is called "hover-gleaning". Other birds are more methodical in their approach to gleaning, even seeming lethargic as they perch upon and deliberately pick over foliage. This behavior is characteristic of the bay-breasted warbler and many vireos. Another tactic is to hang upside-down from the tips of branches to glean the undersides of leaves. Tits such as the familiar black-capped chickadee are often observed feeding in this manner. Some birds, like the ruby-crowned kinglet and red-eyed vireo of North America use a combination of these tactics. Gleaning birds are typically small with compact bodies and have small, sharply pointed bills.