They are one of five species of the endemic Callaeatidae family that includes five species of New Zealand songbirds with fleshy wattles at the gape, strong legs and weak flight.
The five species of birds in this family include the two Kokako species, North Island and South Island Kokako, the two species of Saddleback, (also North and South Island), and the extinct Huia.
Distinctive Facial Mask and Wattles
Kokako are large, dark bluish-grey birds of about 38cm long with a distinctive black facial mask, blue or orange wattles (depending on species), and run or bound along on their long black legs. They are as quick and elegant, moving through the canopy, as they are on the ground (where they often forage for cicadas and other insects).
The adult North Island Kokako has blue wattles (juveniles pink wattles), while the South Island Kokako has distinct orange wattles.
Kakako are renowned for their beautiful, haunting song, usually heard at dawn or dusk, with it’s liquid organ notes and ‘swinging gate’ phrases. They sing from high perches to establish territorial boundaries.
Populations Under Pressure
Early settlers nick-named the North Island Kokako the Blue-wattled Crow, and scientists have confirmed them as part of the early southern corvid radiation (although their systematic position is not certain). Kokako evolved in isolation, after Gondwanaland split into the present southern land masses 80 million years ago.
Kokako were once common in lowland temperate rainforests throughout New Zealand, but the North Island Kokako population is now reduced to about 1400 birds, and the South Island Kokako is “functionally extinct” with only occasional fleeting sightings of single birds.
Settlement of New Zealand brought with it the Black rat (Rattus rattus) which are known to prey on Kokako eggs and sometimes chicks on the nest. This impact was compounded by the introduction of the stoat for rabbit control in the 19th century. Stoats were ineffective on the rabbit plagues, but its ability to climb trees is used to prey on eggs and chicks of many native birds.
Pest Management Vital
The North Island Kokako flourish where intensive pest management is carried out, controlling pest predators such as stoats, rats, possums, and cats. The main Kokako population is found in an area of the Urewera Ranges with many smaller populations in pest controlled, rainforest restoration projects throughout the North Island.
No conservation is done directly with the South Island Kokako population, but some birds are believed to exist in rainforest areas where pest control is carried out for other purposes. Recently, a small number of North Island Kokako were also translocated to a South Island site, to establish a viable population in the south.
Omnivrous Feeders and Short Flyers
Male and female Kokako are alike (weighing about 230 gm), and have long tails and small, rounded wings. Kokako will fly short distances, usually by climbing into the upper canopy, and gliding down to another perch with short, flapping flights.
Kokako are omnivrous, feeding on fruit, nectar, and insects, as well as eating the soft leaves of favored native tree species, such as hangehange.
They usually mate for life, (and are known to live up to 25 years), with the female building the nest and incubating the young. She is fed on the nest by the male who also helps to feed the chicks. Kokako lay one to three eggs, between October and March, and the chicks take about 30 -35 days to fledge.
The best time to see Kokako is at the end of the breeding season when numbers are usually highest, but they can be seen (and heard) at any time of year, (although they are usually quieter during the breeding season). Dawn and dusk are their most active times of day for foraging and singing.
Where to See Kokako
In the Auckland region, Kokako can be seen most easily on Tiritiri Matangi Island (bird sanctuary with regular ferry access), where there is a small, successful breeding population. Quiet observation from tracks at the top of Kawerau Bush and along that end of the Ridge Track is often rewarded with sightings, but there are also territories with reliable sightings throughout the island, including along the Wattle Track and near the Wharf.
Kokako were also recently translocated to the ‘Ark in the Park’ area within the Waitakere Ranges in west Auckland (off Scenic Drive/Falls Road), where the first chicks have already been recorded, and in the Hunua Ranges (in the Kokako Management Zone). These are small, translocated, and intensively managed populations, so considerable patience and skill is required to locate and view birds.
Further south, in the central North Island, Kokako can he seen and heard at Pureora Forest (including off Plains Rd near the Buried Forest, as well as near the Waipapa Ecological Area (eg. at the corner of Ranginui Rd and Fletchers Rd).
There is also accessible Kokako watching from tracks in the Mapara DOC Reserve off Mapara South Road which is off Kopaki Road between SH30 and SH4. On the north eastern side of Lake Rotorua, is the Kaharoa DOC Reserve where a population of more than 100 Kokako are thriving in a pest controlled area run by the Kaharoa Kokako Trust (36 km north of Rotorua).
The Kaharoa Conservation Area has a main track of about 1.2km that follows the Onaia Stream, through some beautiful rainforest that includes rimu, totara, kohekohe, tawa, puketea, and rewarewa trees.
References
Heather and Robinson, (1997), The Field Guide to the Birds of New Zealand, Viking Press.
Worthy and Holdaway, (2002), The Lost World of the Moa: Prehistoric Life of New Zealand, Indiana University Press.
