Yikes. How often does that happen that is known, and is there any other way to sex the chicks at banding ? Are blood samples or some other relativly easy tests available ?
Further does it happen that a female may be driven off the nest, and 2 males raise a brood ?
Doesn't happen often, but does happen. There isn't a project out there that hasn't done it at least once. Not sure if we have had another one, but will check and post here if we have. And no, at banding there is no other way, blood tests would have to be used for genetic testing and that isn't quick or cheap or feasible. Best/quickest way is to measure the feet, which we do. Male bands tend not to fit on females - except the small and female bands fall off males. Had we tried to put female bands on Hurricane, they probably would have been too loose and would have gotten caught on something over the last two years and injured/killed her. As for Mistral who we know was female, we couldn't fit a male band on her despite her small body size, she had female size feet.
As for two males raising young, haven't had any reports, but we have seen on at least one European site (Netherlands) sometimes you can get adolescent young coming back to the nestsite and being tolerated by the parents even with young chicks in the box ... interesting thought though ...
