I'm reading a paper right now by Alistair Dawson, a scientist at the Center for Ecology and Hydrology in the UK. He studies the neuroendocrine mechanisms of seasonal reproduction and other circannual changes in birds. Given that I study similar stuff, it only makes sense that I should be little more read up on his work. Very little is known about when birds transition from breeding to nonbreeding conditions. His research is about all that there is.
For those non science-y types, here's a bone for you. Did you know that the size of testes in seasonally breeding male bird can vary by as much as several 100 fold? That's a huge difference, and it's amazing that we know so little about what controls those changes.
Anyway, he does some really great work. Worth checking out.