Neuromuscular and endocrine control of an avian courtship behavior

In many species of birds, males perform complex visual and acoustic courtsh ip displays to attract and stimulate females. Some of these displays involv e considerable use of the wings and legs, suggesting that they may be contr olled by sexually dimorphic spinal motoneurons and their target muscles. Se x steroid hormones are known to organize and activate many sexually dimorph ic phenotypes, so these neuromuscular systems may also be steroid sensitive . To test these ideas, we have begun studies of wild golden-collared manaki ns (Manacus vitellinus) in Central America. Males of this species establish a courtship arena in the forest, where they perform an elaborate dance tha t includes use of their wings to generate loud snapping sounds. Here we des cribe male golden-collared manakin courtship behavior, including the variou s "wingsnaps." We also review our studies, and those of others, showing sex ually dimorphic properties of manakin wings, the wing musculature, and sex steroid accumulation in the spinal cord. These data suggest that manakins a re useful models for evaluating steroid control of complex peripheral neuro muscular systems. (C) 2001 Academic Press.