i have for some time said "the birds are a lot brighter than some folk" .i think they know something isnt right Buster , i would just let nature take its course . you could maybe place that youngster under a pair who have only had 1 hatch or ,a pair that havent had the eggs hatch . if you do the latter , make a note of the ring number ,i bet (from experience) if reared i can almost guarantee it wont amount to much. mine took longer to type than Tony C , but amounts to the same answer .