Mange arter bliver imidlertid territoriale i yngletiden, så for at formindske risikoen for skader på især hunfugle kan det være nødvendigt at reducere gruppernes størrelse og sikre, at der er plads nok i anlægget.
Many species become territorial during the breeding season, however, so it may be necessary to reduce group sizes and ensure that there is sufficient enclosure space to reduce the risk of injury, particularly to female birds.