Cook Islands

Brown Booby Sula leucogaster ©Andy Walker Website
Birding the Cook Islands

The Cook Islands is fifteen small islands (total land area 240km²), scattered over an area approaching the size of Western Europe, in the tropical South Pacific. Although the 18,000 residents, almost all Polynesian, carry New Zealand passports, the country has been internally self-governing since 1965, and is independently responsible for all environment matters.

The fifteen islands divide socially and physically into a Northern Group of six islands and a Southern Group of nine islands. The five atolls and one sand-cay of the Northern Group, support extensive Coconut Palm plantations for a fickle copra industry. The only resident landbird is the Pacific Pigeon (Rupe), which lives on three atolls, feeding mainly on the fruits of the indigenous Guettarda speciosa (‘Ano).

The most important avian-island in the Northern Group is the uninhabited atoll of Suwarrow, which has been a national park since 1978. Its reef-islets, a mere 1.6km², support regionally significant colonies of Sooty Terns (100,000 pairs), Lesser Frigatebirds (5,000 pairs), Red-footed Boobies (1,000 pairs), Red-tailed Tropicbirds (500 pairs), and locally significant colonies of Great Frigatebirds (200 pairs), Brown Boobies (100 pairs) and Masked Boobies (10 pairs).

The other special seabird-island is Takûtea, an uninhabited sand-cay (1.2km²) in the Southern Group. Its traditional owners, the people of ‘Âtiu, have maintained Takûtea as a wildlife sanctuary since early this century. It has the country’s largest colony of Red-tailed Tropicbirds (1,500 pairs), and the only Southern Group colonies of Great Frigatebirds (100 pairs), Red-footed Boobies (100 pairs) and Brown Boobies (20 pairs). Takûtea is also a regionally important wintering site for the Bristle-thighed Curlew, an Alaskan migrant listed as “Vulnerable” in BirdLife’s Birds to Watch 2.

The Southern Group, with 90% of the land and 90% of the population, is physically diverse with a young volcanic island (Rarotonga), four raised-reef islands (Mangaia, ‘Âtiu, Ma‘uke and Miti‘âro), an almost-atoll (Aitutaki), two atolls (Manuae and Palmerston) and a sand-cay (Takûtea). Rarotonga, the commercial and administrative centre of the country, is the largest (67km²), highest (653m) and most populated (10,000) island. The inhabitants live on narrow, coastal lowland with a highly-modified vegetation, while the mountainous interior is a near-pristine tropical forest supporting three endemic landbirds.

The Southern Group, which includes Endemic Bird Area F29, supports eleven indigenous, non-migratory landbirds. These include: four single-island endemics (Rarotonga Flycatcher, Rarotonga Starling, Atiu Swiftlet and Mangaia Kingfisher); two two-island endemics (Cook Islands Fruit-Dove and Cook Islands Reed-Warbler); and seven multi-island non-endemics (Grey Duck, Reef-Heron, Pacific Fruit-Pigeon, Spotless Crake and Chattering Kingfisher). Only three introduced landbirds have naturalised: Red Junglefowl, Blue Lorikeet, and Common Myna.

The birds of special international interest are the six endemic landbirds, which are all listed as “Vulnerable” or “Critically Endangered” in BirdLife’s Birds to Watch 2. The other bird of special international interest is the introduced Blue Lorikeet, which is endemic to neighbouring French Polynesia, where it has decreased its indigenous range from more than 20 islands at the turn of the century to six islands today.

The single “Critically Endangered” species, and now the most well known Cook Islands bird, is the Rarotonga Flycatcher (Kâkerôri), or Rarotonga Monarch. In 1885 a naturalist recorded that the flycatcher, which had formerly been abundant everywhere on the island, had undergone a serious decline and was almost extinct. Nearly a hundred years later, in the first national bird survey of 1972, British ornithologist David Holyoak saw two, heard three, and estimated the population at one or two dozen pairs. In 1983, British ornithologist David Todd reported 21 birds, and two nests, in the headwaters of adjacent valleys on the south side of the island. In the spring of 1987, New Zealanders Rod Hay, Hugh Robertson and Gerald McCormack launched the Kâkerôri Recovery Programme, under the auspices of the Cook Islands Conservation Service, with volunteers from New Zealand, and financial support from the New Zealand Government and the South Pacific Regional Environment Programme (SPREP). As a result of this continued effort the number of Kākerōri has risen from the low of 29 to more than 132 at the start of the 1996 breeding season.

Mangaia, nearly the same size as Rarotonga, has eroded volcanic hills in the centre surrounded by a kilometre-wide limestone palisade – a raised-reef – reaching 60m elevation and supporting a healthy tropical forest. The fossil record shows that Mangaia had 13 resident landbirds, of which only five have survived, including the Mangaia Kingfisher (Tanga‘eo), a single-island endemic. We treat this rufous-collared kingfisher as a separate species, although some taxonomists have it as a subspecies of the more widespread Chattering Kingfisher.

During the early 1980s, residents of Mangaia were reporting that their kingfisher was declining in numbers, and they blamed the Common Myna, which was successfully introduced around 1960. From the 149 birds seen/heard, the estimated population was between 250 and 450 birds. It was concluded that the kingfishers bred more successfully in the dense Barringtonia patch-forests, and less successfully in open modified-forests where they were disturbed by the Myna.

‘Âtiu, another raised-reef island, has six indigenous resident land birds including the Atiu Swiftlet (Kôpeka), a single-island endemic. This swiftlet is unusual in using an audible clicking to navigate in the pitch-black interior of its breeding caves; the species are restricted to two caves, which supported only 190 nests.

The fourth single-island endemic frequently raising concern is the Rarotonga Starling (‘Αoi), which is restricted to the rugged inland of Rarotonga. Although this species has not been quantitatively surveyed, it is widespread throughout the inland. However, because they occupy relatively large territories, their total number may be relatively low, in the vicinity of, say, 500 birds. The two two-island endemics, the Cook Islands Fruit-Dove (Kûkupa) and Cook Islands Reed-Warbler (Kereârako), are relatively common. The fruit-dove is common on Rarotonga and ‘Âtiu, while the reed-warbler is common on Mangaia and Miti‘âro.

The last resident land bird of special international interest is the Blue Lorikeet (Kurâmo‘o) on the almost-atoll of Aitutaki. [Fossil evidence from several islands show that the indigenous lorikeet of the Southern Cooks was the Rimatara Lorikeet (Kura) extirpation from the Cook Islands sometime prior to the arrival of European settlers in the 1820s.]The first mention of the Blue Lorikeet on Aitutaki was in 1899 when it was referred to as the pet of the natives. Presumably it arrived as a cage-bird in the early 1800s on one of the many sailing ships from French Polynesia, where the species was still widespread. The Blue Lorikeet population has been surveyed several times with estimates of the total population typically ranging from about 1200 bird.

The present indigenous land birds of the Cook Islands are those that survived the two massive environmental upheavals: the arrival of the Polynesians about 2,000 years ago, and the arrival of Europeans since the 1820s. However, provided the Ship Rat (and maybe the Myna) can be controlled, the prognosis for their continued survival is very good.

Top Sites
  • Suwarrow National Park

    WebsiteSatellite View
    The most southern atoll of the Northern Cooks - Suwarrow Island. The island is one of the most important sea-bird breeding areas in the South Pacific.
Contributors
  • Gerald McCormack

    | gerald@nature.gov.ck

Number of Species
  • Number of bird species: 52

    (As at April 2020)
Endemics
  • Number of endemics: 6

    Rarotonga Flycatcher Pomarea dimidiata, Rarotonga Starling Aplonis cinerascens Atiu Swiftlet Collocalia sawtelli Mangaia Kingfisher Todirhamphus ruficollaris Cook Islands Fruit-Dove Ptilinopus rarotongensis and Cook Islands Reed-Warbler Acrocephalus kerearako.
Checklist
  • iGoTerra Checklist

    iGoTerra Checklist
    Fatbirder Associate iGoTerra offers the most comprehensive and up to date birds lists on the web
Useful Reading

  • Birds of Eastern Polynesia: A Biogeographic Atlas

    | By Jean-Claude Thibault & Alice Cibois | Lynx Edicions | 2017 | Hardback | 438 pages, 200 colour photos and illustrations, 70 b/w illustrations, 142 colour distribution maps | ISBN: 9788416728053 Buy this book from NHBS.com
  • The Birds of Hawaii and the Tropical Pacific

    | By H Douglas Pratt, Phillip L Bruner & Delwyn G Berrett | Princeton University Press | 1992 | Paperback | 409 pages, 45 plates with colour illustrations; 48 b/w illustrations, 14 maps | ISBN: 9780691023991 Buy this book from NHBS.com
Useful Information
  • BirdLife International

    Taporoporoanga Ipukarea Society (TIS) is the BirdLife Affiliate
Museums & Universities
  • Bishop Museum

    Website
    The Vertebrate Zoology section includes the Bishop Museum‘s collections of mammalogy, ornithology, herpetology and paleontology specimens…
Guides & Tour Operators
  • Birdman George

    Tour Operator
    I'm George Mateariki your Eco Tour guide on Atiu. I will pick you up in my bush van and take you around the island explaining the history and lifestyle of the people and pointing out the fauna, local medicines and birds. I also include an optional bush trail following the historical Captain Cook trail. Tropical lunch provided. Specialist tours of Atiu's rare birds can also be booked in advance and includes the opportunity to spot the rare kakeori and kopeka birds
Trip Reports
  • 2017 [11 November] - Pete Morris - French Polynesia & the Cook Islands

    PDF Report
    It has to be said, this was not a tour for those that are after a long bird list, with just 80 species recorded, including those seen on the extension. However, the quality was high, with no fewer than 50 diamond birds being recorded – an amazingly high percentage of special birds! The first part of this tour focused on various island groups in French Polynesia. Beginning on Tahiti and Moorea (where we easily found our target endemics).
Other Links
  • Cook Islands Natural Heritage Trust

    Website
    The Cook Islands has only a few species of birds although there are six unique species found nowhere else in the world. These include the very rare Kakerori found only in the high forests on the south coast of Rarotonga and the low forests on Atiu…
  • KiaOrana

    Website
    The Cook Islands are made up of 15 distinct islands. Rarotonga is the capital island. The islands of the Cook group have a total land area of about 92 sq. miles, scattered over a vast 2 million square kilometre area of Pacific Ocean
  • Takitumu Conservation Area

    Website
    Rarotonga's endangered flycatcher bird, the kakerori, is also protected by the Takitumu Conservation Area project which provides guided tours into the southern mountains. The revenue from these trips contributes towards the cost of keeping down the rats which prey on the tiny bird's eggs. Rarotonga's endangered flycatcher bird, the kakerori, is also protected by the Takitumu Conservation Area project which provides guided tours into the southern mountains. The revenue from these trips contributes towards the cost of keeping down the rats which prey on the tiny bird's eggs.

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