Vertical lek placement of forest-dwelling manakin species (Aves, Pipridae) is associated with vertical gradients of ambient light

Abstract

We studied the interaction of ambient light and plumage colour in four sympatric neotropical manakin species which differ in signal colours and vertical lek placement. We estimated bird conspicuousness by modelling chromatic and achromatic background contrast of signal colours in tetrachromatic colour space. Spectral composition of ambient light varies gradually from the understory to the canopy and may affect where manakins lek. Under the given spatial requirements for their horizontal display flights, manakins place their leks at that position along the vertical gradient where ambient light increases chromatic and/or achromatic contrast of their colour signals against the background and/or within their coloration patterns. This suggests that physical factors can be important for placement of display sites, since they may critically influence the effectiveness and efficiency of conspecific communication. © 2003 The Linnean Society of London.