Sex-changing Chickens

[john_conway@mac.com]

My father has (or had) three female chickens. Recently, one of them 
seems to have been turning into a rooster. Having examined the specimen 
personally I can verify that this does indeed look to be the case. It 
has grown spurs, and it's comb is getting larger.

My question is, can some birds change sex? If so, what implications does 
this have for (other) dinosaurs? (Well, they wouldn't have had to use 
the improbable plot device of frog DNA to explain the sex-changing 
dinosaurs in Jurassic Park for a start.)

This could really throw a spanner in the works of studies on sexual 
dimorphism and growth dynamics.

Or is this just a butch hen?