Because she says so
IT IS well known in the reptile world (crocodilians and chelonia) that the sex of the young can be determined by incubating the eggs at different temperatures. It’s called Temperature-Dependant Sex Determination (TSD). Given that birds share a common ancestor with crocodilians, is it possible for birds to manipulate the sex of their offspring? The answer to that is yes, but not through TSD. And why would they want to do that anyway?
Under normal circumstances, the gender of an individual is a random chance. One could surmise that
