The sexual differentiation of birds appears to be less straight forward
than that of mammals. Circulating steroids are clearly important, but
have paradoxical effects. This is a very interesting field, IMHO.
Anyway, there's a great review that just came out. Here's the reference:
Balthazart and Ball. (1995) Sexual differentiation of brain and behavior
in birds. Trends in Endocrinology and Metabolism. 6(1): 21-29.
Good luck.
Scott
