A large female Australasian Bittern (Matuku Hurepo) has been spotted nesting this summer at Otama Wetlands. This is exciting because Bitterns are rarely seen and their conservation status is nationally critical.
Bitterns are large birds with light and brown streaks in their plumage which helps them blend into the raupo wetland grasses and reeds. If approached they exhibit secretive behaviour and are known for their distinctive “freeze pose” straightening themselves up and pointing their beaks into the sky which lines up with the raupo and makes them difficult to spot. When it is windy, they may sway to make themselves blend in more with their environment or flatten themselves on the ground to disappear from view.
The male bitterns have a distinctive booming call during the mating season and these booming sounds can be heard at Otama Wetland during the breeding season. The female birds build their nests from reeds hidden among the wetland vegetation 20-30 cm above the water and lay 3-5 eggs which they incubate for 25 days and raise alone. Bitterns feed on eels, small fish and frogs in the wetland. The ability to see and stab their prey is important for foraging and survival. New Zealand’s Bittern populations have declined by 90% since the 1980s due to the destruction of wetland habitats to create farmland and towns, predators, and poor water quality reducing their food supply.
It is wonderful to experience the Bitterns surviving in our wetland which is also home to other endangered bird species including Fern bird, Pateke, Banded Rail and Skaup. Our ongoing predator control program is helping these species survive.