08 December 2009

Promiscuousness


 Wire-tailed Manakin

Basically, leks, Food not randomly distributed or at least not defended (super abundant). The species are nomadic and have aggregation points, often traditional. The females raise and feed young; mainly fruit-eating birds. Males display together and the females come in. A few males may inseminate most females--One male White-bearded Manakin managed 73% observed copulations; in Sage Grouse: 75% copulations with 10% of males.

Other birds that use leks include flower sucking: Phaethornis; fruit-eating: manakins (except insectivores), cotingas, and birds-of paradise; seed-eating: grouse; and insect-eating: Buff-breasted Sandpipers and Ruff.

Its been suggested that insects in the Arctic are patchily distributed, so Arctic nesting sandpipers make leks near concentrations of insects.

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