By exploring nesting behaviors much can be learned of how birds have adapted to meet the various challenges of reproduction. Nests, the eggs or young in them, and attending parents tempts a variety of predators. The nest structure and location, as well as adult behavior while on the nest determine how much risk is involved. Site Selection Nesting sites may be made by either members of a pair of birds, or constructed jointly. Nest site selection, accompanied by displays are often an important part of pair formation.
Different species select suitable nesting sites in different ways.
The female is the sole determiner if that is in fact the case. If rejected by the female the male will build a new nest in another location. This continues until the female approves. This building and moving may occur as many as 20 times before a female will accept the nest. The males of many tree hole nesting species will sing or display at a site.