North Island brown kiwi Apteryx mantelli

North Island brown kiwi
North Island brown kiwi

Description

  • Large brown or greyish flightless birds with streaked, hair-like feathers and a long bill.
  • North Island brown kiwi males weigh 2 kg, females 2.7 kg. Great spotted kiwi males weigh 2.2 kg, females 3 kg.
  • North Island brown kiwi is the only wild species of kiwi in the North Island.
  • North Island brown kiwi males give distinctive “kiwi” whistle repeated 15-25 times, while females have a hoarse cry, also repeated, but only 10-20 times.

Interesting Facts

  • Nocturnal, spending the day in a burrow, tree cavities or under dense vegetation, e.g. pampas, kikuyu, harvesting debris.
  • Feed on worms, insects, spiders, crustaceans, berries, leaving sign of deep probe holes in the soil.
  • Lay one egg (great-spotted) or 1-2 eggs (North Island brown) in burrow or beneath tree and incubate for over two months.
  • Four genetically distinct forms of North Island brown kiwi are recognised for management purposes: Northland, Coromandel, Western, and Eastern.
  • Research has demonstrated that 95% of North Island brown kiwi young will not survive to maturity in the absence of pest animal control.
  • The impact of pest animals on the larger great spotted kiwi is not as clear, but they are assumed to have a significant impact, particularly at lower altitudes.
  • The North Island brown kiwi population is estimated at c.25,000 birds (2008); approximately 1,000 on the Coromandel Peninsula, and the rest evenly split between the Northland, Eastern and Western forms.
  • The great spotted kiwi population is estimated at c.15,000 birds (2012), with about 55% in north-west Nelson, 30% in the Paparoa Range and 15% in the Southern Alps
  • Many kiwi populations are now managed by controlling animal pests, particularly North Island brown kiwi. Many projects are undertaken by community groups.

Association with Plantations

  • Two of the eight kiwi taxa can occur in plantation forestry; North Island brown kiwi and great spotted kiwi. Indigenous forest and shrubland are the main habitats and rough farmland is also visited.
  • Significant populations occur in several plantation forests in Northland, Coromandel, Tongariro, Nelson and the West Coast.
  • Many other plantation forests may have small isolated remnant kiwi populations.
  • Within plantations, kiwi are often found in log piles, ‘birds-nests’, slashpiles and windrows.

Threats

  • Attacks by dogs, usually causing death.
  • Predation:
    • Of adult kiwi by ferrets, and possibly by possums and pigs.
    • Of chicks by stoats, cats, ferrets, possums and possibly pigs.
    • On eggs by possums and pigs.
  • Deaths from falling into steep-banked ponds and cattle-stops.
  • Hit by vehicles at night.
  • Habitat loss and degradation through land development.
  • Isolation of remnant populations through land development.
  • Forest operations such as slash-burning, harvesting (particularly during nesting) and land preparation.

Management Options and Methods

  • Habitat protection:
    • Protect indigenous vegetation, including corridors and riparian habitat where kiwi frequently forage.
    • These areas will provide refuge during harvesting and access to other habitat areas.
    • If the kiwi population is not viable then contact DOC for other options, e.g. relocation advice.
  • Forest harvesting where kiwi are present:
    • Ascertain if they have escape routes to alternative habitat, especially indigenous habitat.
    • Stage harvesting to keep escape routes open for as long as possible.
    • If kiwi are in danger from harvesting or have no alternative habitat locally, seek advice from DOC staff about other options, e.g. translocation.
  • Post-harvest:
    • Avoid grazing, burning or spraying in order to encourage recovery of vegetative cover and higher ground moisture levels.
    • Avoid disturbance of known kiwi habitat (i.e. slash piles) during land preparation.
    • Avoid burning ‘birds-nests’ in which kiwi often roost. If burning is necessary, use precautions, e.g. night burning (when kiwi are active), or using a certified kiwi dog to assist in removal of kiwi.
  • Pest control:
    • Critical to exclude all dogs, or allow only those dogs with kiwi-avoidance training.
    • Implement alternative pig control methods, e.g. hunting without dogs, poisoning, trapping.
    • Work with local community and DOC towards exclusion of dogs from all kiwi zones.
    • Intensive mustelid and cat control is critical to retain viable populations.
    • Maintain possum numbers at moderate to low levels. (Undertake 1080 possum operations to provide maximum benefit to kiwi and other biota through secondary kill of predators (also consider benefits of integrated pest control to kereru and other species).
    • Maintain contact with DOC, councils, landcare groups and other groups to co-ordinate pest control.
  • Injured or dead kiwi:
    • In the event of an injured bird, place in a darkened box or carton and keep warm, but not in direct sunlight, while being delivered to SPCA or a local vet.
    • Call DOC if you find a dead bird.

Survey and Monitoring Options

  • Increase staff and contractor knowledge about kiwi and keep a record of sightings, calls and evidence of sign.
  • Look for kiwi probe holes in likely areas.
  • Determine kiwi presence using night call-count surveys supplemented with play-back taped calls.
  • To determine core kiwi areas, use standard call-count survey techniques, e.g. two hours per station over 2-3 nights, without using taped calls.
  • For monitoring of kiwi abundance over time, select representative monitoring stations (at least five per forest) and carry out four nights of call-count listening annually.
    • May and June are the best months for hearing kiwi calls.
    • Monitoring should be undertaken on dark, moonless nights when calls are more frequent.
    • Refer to Robertson et al. 2004 for detailed monitoring techniques.
    • Liaise with DOC about kiwi survey and monitoring methods.
  • Report findings to DOC.

Further Information and Support