Hi I would like to find out if anyone heard of this before as we have had great tits in our garden for a few years, but this has been different, 2 nest boxes 20 metres apart cameras in both boxes, first great tits nest in box 1, 10 eggs all hatched half way through feeding the cock bird disappeared leaving hen to rear 2 chicks managed to fledge hard work for hen bird, but then half way through the feeding a new cock came on the trying to get her in nest box 2 he followed her back and forth while hen feeding young but he didn’t do any feeding, after about about 2 wks they came back he got her to nest in box 2 8 eggs hatched now he has vanished not seen him for a wk, I can’t work out what’s going on, any one else any idea, I live in Leicestershire