 Common starlings are both monogamous and <unk> ; although broods are generally brought up by one male and one female , occasionally the pair may have an extra <unk> . <unk> may be part of a colony , in which case several other nests may occupy the same or nearby trees . Males may mate with a second female while the first is still on the nest . The reproductive success of the bird is poorer in the second nest than it is in the primary nest and is better when the male remains monogamous . 
