Table 1. A description of the behavioural parameters that were scored during the time inbred and outbred males were exposed to a female behind a peephole.

Behaviour	Description
Attack	Pecking and using feet to (attempt to) pin the opponent down
Beak wipes	Rubbing the bill along a substrate repetitively
Chase	Chasing the opponent in flight
Escape	Escape from a chase or attack by flying away from the opponent
Feather shuffle	Briefly pilo-erecting the feathers with a shuffling movement
Move away	Stepping away from the opponent without flying away
Preening	Scratching and/or cleaning the feathers
Threat display	Staring at the opponent with the wings spread out and the head lowered
Time spent peeping	Time spent in front of the peephole and looking at the female
Time spent on perch A	Time spent on the perch that gives visual access to the peephole
Time spent on perch B	Time spent on the perch that does not give visual access to the peephole