lagoon, and perhaps the best place in the world to see this secretive bird is amongst the oioi rushes on the Ōkārito Wetland Walk – this vegetation is not as good a hiding place as their usual scrub habitat. Pairs can be heard making a call-and-response u-tick call. Australasian bitterns and marsh crakes also inhabit the wetlands but are far harder to spot. The juvenile fishes known as whitebait are common here, and so are whitebaiters during the September–mid-November season. The lagoon also contains longfin eels, flounder and yellow-eyed mullet. The mudflats are home to tunnelling crabs / papaka (Helice crassa), mudsnails / titiko (Amphibola crenata), and mudflat topshells (Diloma subrostratum). Flounder and shellfish populations are currently in good health. Kōtuku For many New Zealanders, Ōkārito is synonymous with the white heron (Ardea alba modesta), commonly referred to by its Māori name kōtuku, and known outside New Zealand as the Eastern great egret. This subspecies of great egret is quite common throughout Asia and Australia, but in New Zealand the white heron is extremely rare. When Queen Elizabeth II visited New Zealand in 1953–54, she was compared to the kōtuku – a compliment given to rare, distinguished visitors. The kōtuku is featured on the reverse side of a New Zealand $2 coin. There is only one breeding site for White Heron in New Zealand: within the protected Waitangiroto Nature Reserve, north of Ōkārito Lagoon. Kōtuku share the colony with royal spoonbills, known as kōtuku ngutupapa. From this colony, kōtuku disperse throughout New Zealand, but return to this spot to breed. The first European to see the colony was surveyor Gerhard Mueller, who was guided there by Kere Tūtoko in 1865. There were only four nesting pairs of kōtuku in 1941 when the land at Waitangiroto was compulsorily acquired by the New Zealand government and gazetted as a nature reserve. The New Zealand population of kōtuku is around 180. About 8–10 white herons are resident year-round at the Ōkārito Lagoon, are most common seen between October and March. They can be observed relatively close up while kayaking on the lagoon, and regular birdwatching tours visit the colony from Whataroa. History Māori occupation and seasonal harvesting in the area began over 600 years ago. Ōkārito was an important mahinga kai (food-gathering site) for Kāti Māhaki ki Makaawhio, a subtribe of Ngāi Tahu, who were collecting and working pounamu for trade. As part