I think you may be right! I think I said this in an earlier post, but when they were being 'put back' after the banding I heard one of the banders say something along the lines of "here is your big sister". So one girl forsure.
Also, I don't know if band color has anything to do with sex, but I saw (what I thought was) a purple band on one of the chicks who was sleeping faceplant style with legs sticking out and figured that purple is kind of a girly color...
'Fraid, girly colour or not, we don't have different colour bands for different genders. The purple band is the aluminium FWS band they use in the States, the other band, probably black over green since it is a Midwest nest is the band with the big numbers/letters that we/they use for identification. If you really want to start tracking whose doing what, read their band numbers, or at least make spot the difference (ie: one has a P, one has an X and it doesn't matter what the rest of the numbers are).
The two bigger chicks will be the females, the smaller the male. Last year's Radisson nest was very (very) unusual when it came to chick size, no one could believe us that the middle and smallest sized chicks were female (Taku & Mistral respectively) at banding. By the time they were all ready to fledge however, Mistral was as big as Chinook so she made up for lost time.
