On the basis of long-term works in Irkut river mouth (1983-87) existence of well expressed selectivity certain microhabitats among waders is proved. It is shown, that at studying features of spatial structure of these species, and also uses for nesting various microhabitats, during works the water level should be taken into account. Most precisely specific preferences of these species can be revealed during a low water level. Most likely, the principal cause segregation of waders during the nested period on microhabitats is connected to necessity of decrease of an interspecific competition. Segregation raises the general population density of birds in a monotonous habitat and it allows to be distributed in regular more intervals on territory, and also optimally to use favourable sites nest habitats.