White heron Ardea modesta

White heron/kōtuku
White heron

Description

  • Kōtuku can stand a metre tall. It is pure white with a yellow bill and dark legs, and a very long neck.
  • The bill becomes much darker when breeding and long filamentous feathers form on its back.

Interesting Facts

  • Kōtuku are found throughout the world, but the population in New Zealand is restricted to one breeding location, and numbers only 150-200 birds. It is believed to be stable.
  • Kōtuku have probably always been rare in New Zealand, but almost became extinct when their only breeding location on the Waitangituna Stream, Okarito, South Westland, was discovered in 1865, and the birds were killed for their long, white feathers which were used to adorn women’s hats. By 1941, only four nests remained.
  • Birds disperse throughout New Zealand after breeding.
  • Kōtuku have few threats away from their Okarito breeding grounds. The most common cause of mortality is being hit by cars.
  • All wetland birds require high quality wetland habitat buffered from the effects of surrounding land management.

Association with Plantations

  • Wetland birds are found in many plantation forests.
  • Birds may be hard to detect due to their elusive behaviour.

Threats

  • Habitat loss and degradation from wetland drainage, loss of riparians, and the effects of surrounding landuse are general threats to all wetland birds.
  • Invasion of exotic plants, which can seriously modify wetlands and their suitability for birds.
  • High predation rates of some wetland bird species such as brown teal are well documented; the level of predation on many other species, however, is unknown.

Management Options and Methods

  • Habitat protection:
    • Protect important wetland habitats and riparian buffers.
    • Avoid using herbicides or pesticides close to wetlands.
    • Ensure weeds are not inadvertently introduced to wetlands, e.g. via machinery or boats.
    • Consider control options for existing invasive wetland weeds.
    • Consider a staged removal of willows to ensure ongoing cover for crakes and ducks.
  • Forest operations:
    • Minimise damage to riparian and wetland habitat during road construction and harvest operations.
    • Avoid grazing wetlands and their margins. Fencing may be appropriate in some situations.
    • Avoid diverting run-off into wetlands.
    • Minimise disturbance during spring breeding.
    • If pateke are present, discuss predator control with neighbours and DOC.
  • Injured or dead wetland birds (particularly the more threatened species, i.e. white heron, bittern and pateke):
    • Place injured birds in a cardboard box (keep shaded) and deliver to a local vet, SPCA, DOC.
    • Call DOC if bird is dead.

Monitoring Options

  • Increase staff and contractor knowledge about wetland birds.
  • For important wetlands that are likely to have the more threatened species, consider undertaking a bird monitoring programme.
    • Counts of pateke flock sites in late summer.
    • Fernbirds, spotless crakes and to a lesser extent marsh crakes and banded rails respond to taped playback calls.
    • The booming calls of bittern are characteristic at dusk in September-October particularly during bright moonlight.
  • Maintain a database of sightings.

Further Information and Support