Transfer effect

The transfer effect is a term used in ornithology to describe the phenomenon observed among the bowerbirds, in which there is a continuum from physically more ornamented species which construct rudimentary bowers (mating display nests), to physically drabber species which construct remarkably elaborate and colorful bowers.

The postulation is that there is an evolutionary "transfer" of ornamentation, as a sign of male mating health, from physical characteristics to behavioral ones — with the benefit of reducing the visibility of the male and thereby its vulnerability to predation.