Evolutionary mechanisms maintaining nest construction in avian clades.

Most birds construct nests where they raise dependent young, and in some instances species will use a nest as a protective roost for part or all of the year. Given the direct connection between nests and fitness it is likely that nest-building behaviour is responsive to selection. Traditionally, nest-building behaviour was thought to be solely influenced by selection to maximise direct benefits via the survival and growth of offspring. However, recent work has shown that other evolutionary mechanisms may considerably influence nest-building behaviour. I describe a suite of mechanisms that may maintain nest-building behaviour in avian clades and discuss the current evidence for each of the mechanisms. I then suggest potential future avenues of research that could provide useful results for delimiting both proximate and ultimate factors that influence the evolution of nest construction. [ABSTRACT FROM AUTHOR]