Biodiversity

May

2026

A Tree, a Bird and a Beetle

Gerald McCormack, CINHT,

Neinei Tree, Leaves and flower – Cook Islands, Rarotonga – Gerald McCormack

The Neinei tree of Rarotonga has such a spectacular flower that the tree itself is often called the Pua Neinei (Flower-of-the-Neinei). The Neinei (Rarotonga Fitchia) is a small tree common in the mountains, from the base of low valleys to the top of the highest mountains. It is not found anywhere else in the world, although it has a few shrubby relatives in French Polynesia.

The large leaves are in terminal bunches, and they often have conspicuous grooves, cut inward from the edge. These are the feeding grooves of the 15mm Neinei Weevil (Rhyncogonus lineatus), which feeds exclusively on the young leaves of the Neinei. Like the plant, this weevil is not found anywhere else in the world, although it does have close relatives in Hawaii as well as in French Polynesia.

The Neinei flowers from April to June. The flowers are large, spiky, bright orange and full of nectar.

Neinei weevil, Adult [16mmBL] – Cook Islands, Rarotonga – Joseph Brider 2020-12

One animal which seeks the nectar as food is the `Ī´oi (Rarotonga Starling). The flower of the Neinei is bent back towards the branch, probably to make it easier for the starling to get to the nectar. Because, while the starling searches for the nectar, it pollinates the flower, thereby enabling the plant to develop seeds. The dark grey `Ī´oi, which has a bright yellow eye, is the most melodious native bird on Rarotonga. It’s typical call of “ee-oi, ee-oi, ee-oi”, is reflected in its Māori name.

The Rarotonga Starling is not found anywhere else in the world, and its closest relative, the Mauke Starling (Aplonis mavornata) of Maºuke, which was last recorded about 150 years ago, in 1825. In the olden days the `Ī´oi was the protector of fugitives and food-gatherers in the forest, because it called when other people approached. A famous traditional saying was: `Ī´oi -karanga (starling warns).

Rarotonga Starling, Adult emerging from nest-hole in tree trunk – Cook Islands, Rarotonga – Gerald McCormack

The fame of the starling’s warning call was reflected in the first anti-government newspaper, the Ioi Karanga, published during 1898.

Moss launched the bilingual Te Torea in 1894, it was published by Henry Nicholas, a European-NZ Maori in Rarotonga since the 1860s, on the leased Government printing press. The first Catholics and SDAs settled on Rarotonga in 1894. The SDAs included the American SDA Dr Caldwell, who became the first resident doctor in 1894 and a makeshift hospital was opened in May 1896. In October he was told to stop having religious meeting in the hospital. The Craig brothers arrived in March 1897 and Dr George Craig was within weeks made hospital superintendent. Craig and a number of Europeans started to strongly oppose Moss’s administration. In January 1898 Makea Ariki, exploiting anti-Moss situation, had the printing press forcibly taken from Nicholas as part of her own campaign against Moss. She then started to print the Ioi Karanga on the press. A short-lived newspaper. In mid-1898 Moss, in ill-health and 71 years old, resigned. He left in September. Gudgeon immediately appointed George Craig as medical officer.

Author’s notes

First published CINEWS(3 July 199) updated (September 2010)

May

2026

The Blue Lorikeet (Kurāmo‘o) of Aitutaki

Gerald McCormack, CINHT

Adult on Banana leaf and flower – Cook Islands, Aitutaki – Joseph Brider 2021-10

The Blue Lorikeet (Vini peruviana ) is a native bird of French Polynesia, formerly existing on about twenty islands in the Society Islands (including Tahiti) and the northern Tuamotu atolls. In recent years it has been lost from Tahiti and all the main Society Islands, surviving only on three remote atolls to the northwest (especially Bellinghausen/Motu One) and on three or four atolls of the Tuamotus. Continue reading →

May

2026

Toa – Pacific Ironwood

Gerald McCormack, CINHT

Leaves, flowers and fruit (1) – Cook Islands, Rarotonga – Gerald McCormack

The Toa (Ironwood) of the Cook Islands, Casuarina equisetifolia, is a native tree of Malaysia, Australia and some islands in the western Pacific. It was probably spread eastward through Southern Polynesia by the ancient Polynesian settlers, and now grows naturally on many islands.

Throughout the Southern Group it grew well and spread naturally along the shorelines and into the fernlands of the inland mountains. In contrast, it did not grow well nor spread itself on the northern atolls, where it is uncommon, rare or absent.

The thin green parts which look like leaves are not leaves; they are green branchlets, which perform the leaf-function of changing the energy of sunlight into the energy of sugars. When you snap a branchlet, the minute pale projections at the break are all that remain of the true leaves.

Leaves, flowers and fruit (2) – Cook Islands, Mangaia – Gerald McCormack

Although the Toa looks like a relative of the pine tree, it is more closely related to the hibiscus and gardenia than the pine. The Toa is a flowering plant. The female flowers are each represented by a delicate pink filament on a small knob on the branch among the green branchlets. When they have been pollinated the knob grows into a woody fruit which contains lots of small seeds. The pollen is made by the male flowers which are the pale, bushy tails, typically on the ends of some branchlets.

Toa in general, and sometimes the heartwood (taiki), is the preferred wood for making many things, such as: beaters (tïtï) for slit-gongs; outrigger booms (kiato) on canoes; planting sticks for Taro (pao-taro); adze-handles (kakau-toki); recreational throwing discs (pua); and, parts of the framing of traditional dwellings. In pre-Missionary times it was also used to make spears (räkau), clubs (patu) and God-images (atua).

A solution made from scrapings of the inner bark is one of several herbal medicines (vai räkau) used for mouth thrush (kea) in children and for some urinary problems (mimi and mimi-tätua).

The English name Ironwood is used in different countries for different species of trees and is therefore confusing to overseas visitors. In Australia Casuarina equisetifolia is known as Beefwood, Horsetail Tree or Sheoke. The name Sheoke is thought to be a combination of ‘sshh’ (the sound of the wind passing through the branchlets) and ‘oak’ (the wood being very hard, like European Oak).

Author’s notes

First published CINEWS (18 June 1994)

May

2026

Meet the Ghost Crabs of Our Shores!

Cindy Milanovic, CINHT,

Pale Ghost Crab, Pukapuka – Gerald McCormack

Have you spotted a pale, fast-moving blur darting across the beach at dusk? Chances are you’ve met one of our Ghost Crabs! They are responsible for those small, deep holes you see in the sand.

Two species call the beaches of the Cook Islands home:

Pale Ghost Crab Ko’iti (RR) –Ocypode pallidula — About 2.5 cm wide, their name literally means pale. They dig burrows by flipping sand in a distinctive fan shape, sealing the entrance tight when the tide rolls in.

Horn-eyed Ghost Crab Kohite (RK) –Ocypode ceratophthalmus — Named for its remarkable horned eye-stalks. A fierce predator and one of the fastest crabs in the world! Both belong to the Long-eyed Crab family and are clever engineers of our beaches — emerging at dusk to hunt, then retreating to sealed burrows as the tide returns. With their diets consisting of tiny animals and rotting material along the shoreline and amongst the plants that habitat coastal areas, they play an important role in maintaining a healthy beach ecosystem.

How you can help: → Admire from a distance → Never dig up their burrows → Walk softly at dusk when they’re most active→ Protect habitat by allowing foreshore vegetation to grow.

Ghost Crabs as Eco Soldiers.

Horn-eyed ghost Crab, Pukapuka – Gerald McCormack

Ghost crabs are far more than the pale, darting shadows we glimpse at dusk — they are key engineers and custodians of the beach ecosystem. As predators, they control populations of insects, small invertebrates, and beach fauna, helping to keep the foreshore community in balance. As scavengers, they act as nature’s cleanup crew, rapidly breaking down dead fish, organic debris, and carrion that washes up along the strandline, recycling nutrients back into the beach system. Their burrows are equally important — by constantly excavating and turning over sand, they aerate the beach substrate much like earthworms do in soil, improving drainage and sediment health. These same burrows also provide shelter for other small organisms. As prey themselves, ghost crabs are a vital food source for shorebirds such as the reef heron, and larger predators, connecting the beach to broader food webs. In short, a beach with a healthy ghost crab population is a beach that is functioning well — and their absence or decline is one of the earliest warning signs that a foreshore ecosystem is under stress from human disturbance, pollution, or habitat loss.

The Foreshore Ecosystem and Ghost Crabs.

As a food source itself

Both species of crabs are omnivores and opportunistic scavengers. Rotting coconut fronds and decaying vegetation create organic matter that ghost crabs will directly consume. The O. pallidula in particular, being described as a nocturnal scavenger, will feed on decomposing plant material as part of its varied diet.

As an insect and invertebrate factory

This is probably the most significant link. Decaying fronds and rotting coconuts attract and harbour large numbers of insects, beetles, flies, amphipods, isopods (sea slaters), and worms — all of which are prime ghost crab prey. The crabs essentially have a buffet laid out for them along the foreshore at night.

As habitat for other prey

Vine tangles and debris along the foreshore provide shelter for small crustaceans, molluscs, and other invertebrates that ghost crabs hunt. The denser and more complex the foreshore habitat, the richer the community of crabs living within it.

As a moisture and microclimate regulator

Foreshore vegetation slows drying out of the upper beach and maintains cooler, moister conditions — important because ghost crabs need to periodically wet their gills to breathe air. A vegetated foreshore extends the zone where crabs can comfortably forage without having to return to the waterline to wet their gills.

As a structural refuge

Vine and debris tangles at the back of the beach give ghost crabs cover from predators like herons and reef herons (Egretta sacra — Kōtuku (RR)) while they forage. This allows them to range further up the beach and spend more time feeding.

The broader picture

A stripped, heavily raked, or “cleaned” beach foreshore — as is common near resorts and public beaches — actually reduces ghost crab food availability significantly. It removes the insect habitat, the decomposing organic matter, and the structural cover they depend on. Many people assume a tidy beach is a healthy beach, when ecologically the opposite is often true.

Author’s notes

First published Cinature.org (4 May 2026)

May

2026

Hummingbirds in the Cook Islands?

Gerald McCormack, CINHT

Sometimes in the evening bird-like creatures hover over flowers while probing them with a long slender beak. Are they hummingbirds?

Gnathothlibus erotus Caterpillar or Hornworm – Cook Islands, Manihiki – Gerald McCormack

Although they look like the hummingbirds of books and films these creatures are actually large moths, known as hawk-moths or sphinx-moths. They have strong slender wings enabling them to fly very fast and to hover. They are nocturnal feeders, usually starting around dusk. Their caterpillars are called hornworms, because they have a long horn on the rear end. Continue reading →

Biodiversity

A Tree, a Bird and a Beetle

The Blue Lorikeet (Kurāmo‘o) of Aitutaki

Toa – Pacific Ironwood

Meet the Ghost Crabs of Our Shores!

Ghost Crabs as Eco Soldiers.

The Foreshore Ecosystem and Ghost Crabs.

As a food source itself

As an insect and invertebrate factory

As habitat for other prey

As a moisture and microclimate regulator

As a structural refuge

The broader picture

Hummingbirds in the Cook Islands?

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