More Top Stories

Letters to the Editor
Local

Top cop position advertised

7 December 2024

Culture
Church Talk
Court
Economy
Economy
Economy
Education

New discoveries add to Cook Islands’ rich biodiversity

Saturday 18 January 2025 | Written by Supplied | Published in Features, Weekend

Share

New discoveries add to Cook Islands’ rich biodiversity
On Penrhyn, in April and May, Victor Niukore and Aeata Matara recorded the first Franklin's Gull (Leucophaeus pipixcans) in the Cook Islands. This Canadian-US gull breeds April-September and then migrates southward to western South America to escape the northern winter. A few birds end up elsewhere, such as Hawai‘i, Australia and New Zealand. It is easily confused with the Laughing Gull, which has been locally recorded several times. The images enabled an identification. Photos Tracy McCarthey and Aeata Matara. 25011756

The Cook Islands Biodiversity and Ethnobiology Database recently added 338 new species, including four new intertidal air-breathing limpets, the Erythrina Borer moth not recorded in 90 years, and a mysterious moth never seen before, writes Gerald McCormack of the Cook Islands Natural Heritage Trust.

The Cook Islands Biodiversity and Ethnobiology Database (CIBED) has been online since 2003 through the Bishop Museum in Honolulu.

After several years of restructuring, it reopened in 2023 for the addition of new species at its new home address:  https://naturalheritage.gov.ck/


Mathias Hagen found the first record of the blood-sucking Tropicbird-Booby Lousefly (Olfersia aenescens) on nestling Tavake on Maina-iti (Honeymoon Island), Aitutaki. They are very agile and fast, and some nestlings had a heavy load of 12 flies. There is a need for a veterinary assessment of the impact of this parasite on nestlings and the infestation level in the large Tavake colonies of Palmerston and Takūtea. Photo: CINHT. 25011751

The Natural Heritage Trust was established under an Act of Parliament in 1999 to record the traditional and scientific information on local plants and animals, both marine and terrestrial. 


Twenty-nine beetles were added to the Cook Islands Biodiversity and Ethnobiology Database during 2024 – some new and some oldies finally processed. One oldie was the Rugous Little Dung Beetle (Neotrichiorhyssemus hirsutus). This little beetle helps remove decomposing vegetable matter. Beetles typically have a thick exoskeleton for protection from predators. Here, we see the rigid wing covers (elytra) raised and the fragile wings unfolded as it readied for flight. Photo CINHT. 25011759

The Cook Islands Biodiversity and Ethnobiology Database has core information on 4533 species, including 338 added since 2023.


Noah’s Giant Clam (Tridacna noae) was confused with the Small Giant Clam (Tridacna maxima). The separation was proposed in 2004 but not generally accepted until 2014. Rarotonga jumped the gun with a Research Grade record on iNaturalist in 2011, although genetic confirmation did not occur until 2023 in a Morejohn et al. paper. Pa‘ua is now two native species – both at risk. Photo: M.Solomonson. 25011750

In most countries, biodiversity databases focus on particular taxonomic groups, such as flowering plants, birds, fishes, agricultural pests, and lizards. The Biodiversity and Ethnobiology Database is unusual in being able to record every type of living creature in the Cook Islands, even bacteria.

In the Database, different groups are at very different stages of completion.


In December, Maja Poeschko found the Erythrina Borer moth (Terastia sp.) on an ornamental Cockspur Coral Tree (Erythrina crista-galli). This moth was last recorded 90 years ago, in 1937. Both sexes rest with their bulbous abdomen strongly uplifted for reasons not understood. The Pacific has irregular distributions of a Central American and a Southeast Asian species. Our species is yet to be determined. Photo: CINHT. 25011752

For example, native flowering plants, at 185 species, are essentially complete, while introduced flowering plants, at 1010 species, are incomplete, and more are arriving yearly. Nearshore fishes at 555 are relatively well recorded, although we know about fifty to be added. Seabirds, landbirds, migrants and vagrants stand at 85, which is complete except for the unpredictable arrival of vagrants, as recorded in this article for an American bird found on Penrhyn.


In 2021, Kirby Morejohn found this paper wasp (Polistes olivaceus) riddled with a zombie fungus (Ophiocordyceps sp.) on the Summit of Maungatea in December 2021. Zombie fungi chemically altered the wasp’s brain, causing it to fly higher and higher before locking its jaws on the edge of a leaf to die. From this vantage point, the fungi release spores that are widely dispersed by the wind and eventually infect other wasps. Photo: CINHT. 25011753

Marine shellfish are probably relatively complete at 412. However, as reported in this article, recent findings of four new intertidal air-breathing limpets show how unrecorded species hide in plain view.


Samuel Brown photographed this 2-centimetre-wide moth in Takuva'ine near the inland road in October 2024. The Trust identified it as the Orange China-mark Moth (Parapoynx villidalis), a new record for the Cook Islands. It is a native of Asia and Australia. The only other record in the Pacific is in Fiji (1992). Its caterpillar is aquatic in pools and wetlands, breathing through filamentous gills and eating aquatic plants. Photo: SDJ Brown. 25011757

Insects are the most under-recorded group, and most new records in the Biodiversity and Ethnobiology Database are insects, now numbering 816. We estimate there are more than 2000 insects in the Cook Islands.


Mysterious Jewel Moth. This minute, 3-millimetre moth was caught in Aitutaki in October 2024. The Trust could not identify it despite its dramatic silver spots on an orange background. The images were sent to experts in French Polynesia, Hong Kong, the Netherlands, and Finland. None could identify it or reliably put it into a family of moths. This is the Trust’s first encounter with such a mysterious moth. It is probably an endemic of Aitutaki. Photo CINHT. 25011758

The most threatened group are native landsnails, with 53 extant and 15 recorded as extinct. Although the Convention on Biological Diversity commits us to prevent extinctions, we have no national projects on our native land snails.


Rarotonga’s giant ant was first reported by Kevin Henderson in equipment around Avatiu Harbour in 1999. The Trust recorded it as the Pacific Carpenter Ant (Camponotus chloroticus), assuming a Pukapuka origin. In January 2024, the Trust posted new detailed images on iNaturalist, and specialists identified them as the Caribbean Banded Carpenter Ant (Camponotus zonatus), previously found only in the Caribbean, Central America and the Galapagos. How it got to Avatiu is unknown. Photo CINHT. 25011755

This article draws attention to some of the species recently recorded in the Cook Islands Biodiversity and Ethnobiology Database.


A new reef species on Ātiu. This species of Siphonaria, an air-breathing limpet was photographed in 2009 without identification. In 2022, expert Bruce Jenkins identified it as a new Pacific species unique/endemic to the Cook Islands. Bruce increased the Cook Islands Biodiversity and Ethnobiology Database Siphonaria from two to six. Two were Pacific species not noticed locally, and two were new to science - one on Rarotonga and this one on Ātiu. Photo: CINHT 25011754

A special meitaki ma‘ata to the many who informed us of unrecorded species.

Comments

Leave a Reply