Threats to white heron/kōtuku
The white heron has always been rare in New Zealand. Why the kōtuku has not colonised a wider breeding ground is a mystery, but the current population is stable, although it experiences year-to-year fluctuations in breeding success.
White heron in water
Natural variables, such as storms hitting during the early part of the nesting season and the condition of the nearby Okarito Lagoon, are significant factors in determining breeding success. The kōtuku requires shallow water for feeding, and this habitat can severely reduce in certain years when the outlet of the lagoon gets blocked. The damming of the lagoon may also disrupt the migration of whitebait, which is a major food source for kōtuku.
The kōtuku colony is situated in extremely close proximity to a shag rookery and a Royal Spoonbill colony. The success of any of these three species may place pressure on the relative success of the other two.
Predators like stoats, possums and harrier hawks may threaten breeding success at various times, and control programmes are in place for both stoats and possums.
back to top
Learn more
White heron colony tours at Waitangiroto Nature Reserve www.whiteherontours.co.nz
Contacts
Phone 0800 DOC HOTline (0800 362 468) 24 hour emergency number to report:
Sick or injured wildlife
Whale or dolphin strandings