Crossbills

Went for a little twitch today - Great Grey Shrike (success), Crossbills (success), Rose Coloured Starling - failed. We saw three parties of Crossbills at Glynaeron, always feeding with Siskins. There were males and juveniles (one extremely red male - very smart) - but I didn't notice any females. Could they be sitting on nests?? There seems to be plenty of food around to support a second brood.