Review Note

Molt is triggered by increasing {{c1::photoperiod}}, {{c1::temperature}}, and {{c1::nutrition}}. New feather growth causes {{c2::increased}} metabolic rate. 
{{c3::Androgen}} and {{c3::estrogen}} appear to {{c4::inhibit}} molt until after the breeding season. 
{{c3::Progesterone}} prevents ovultation and {{c4::induces}} molt by stimulating feather papillae.