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Ten years later, rare bird is well established on Atiu

Monday May 01, 2017 Written by Published in Weekend

Gerald McCormack director of the Natural Heritage Trust, explains the story behind the success of establishing the Kura (Rimatara Lorikeet) on Atiu, where the bird had previously been absent for 200 years.

 

Ten years ago, April 24, 2007, Air Rarotonga flew 27 Kura (Rimatara Lorikeets) on a direct flight from Rimatara to Atiu, where the bird had been absent for 200 years.

This was the first transboundary reintroduction of a bird in the Pacific and the story was reported by more than 130 major news outlets around the world. TVNZ showcased the event with Greg Parker’s “Spirit of the Queen” documentary, which is on YouTube at www.youtube.com/kokamedia.

In pre-historic times the Kura had been throughout the Southern Cooks and eastward to Rimatara and Rurutu in French Polynesia. It had been lost on all islands, except Rimatara by the over-harvesting of its red feathers for personal adornment.

The purpose of the project was to establish a second population to maintain the Kura within its former natural range in case it was devastated on Rimatara by an invasion of ship rats. The Natural Heritage Trust and MANU, the Ornithological Society of French Polynesia, took six years to negotiate approvals with government agencies and the Rimatara community, which gave the birds into the care of Rongomatane Ariki and the Atiu community.

The April transfer was implemented by an international team with special expertise provided by San Diego Zoo.

The project cost over NZ$100,000. It was funded by the British Birdwatching Fair through BirdLife International, with essential co-financing from Fonds Français pour le Pacifique, Cook Islands Government, Air Rarotonga, Pacific Development and Conservation Trust, Loro Parque Foundation, Zoological Society of San Diego and WWF.

The Natural Heritage research of 1992, which lead to the reintroduction, found there were about 900 Kura on Rimatara and they almost all lived in the man-modified horticultural zone. They fed mainly on flower nectar, especially on bananas, coconut and sleeping hibiscus.

Since their reintroduction to Atiu, Kura have become common throughout the inland horticultural areas where they feed on similar plants to those used on Rimatara.

2008 August

During the first year after the reintroduction, Kura were regularly seen in different areas of the inland of Atiu, which confirmed that most or all had survived the trauma of the translocation.

Natural Heritage and San Diego Zoo organised the first assessment in August 2008. Although we were unable to count the number of Kura, we were able to monitor the first reported nest.

The nest was a hole in the end of a rotten branch high in an Albizia. The parents successfully fledged two young, which proved that Kura can breed on Atiu.

When one fledgling emerged from the nest it was knocked to the ground by a pair of aggressive mynas. Although we assisted it to rejoin its parents this assault lead to the start of the myna reduction programme in June 2009.

Atiu after 10 years

Ten years later in October 2016, Natural Heritage and San Diego Zoo reassembled some of the original team on Atiu to assess the health of the birds and estimate their number. The team consisted of Gerald McCormack of Natural Heritage, Alan Lieberman and veterinarian Bruce Rideout of San Diego Zoo, Roger Malcolm and George Mateariki of Atiu, along with new members Elaina Bufano, Liam Kokaua  and Alanna Smith.

The team worked in pairs and triplets to increase the chance of hearing or seeing Kura within 50m of the eight road-transects, which totalled 29km in length with an area of 292ha (hectares). The counting on each transect started at 6am and lasted for up to two hours; the team completed 40 hours of searching over a period of ten days.

The average number of birds detected within 50m of the eight road-transects totalled 100. The area sampled by the transects was 292ha or 26.5 per cent of the 1,100ha inland. We multiplied by 3.77 (100/26.5) to upscale our transect sample for the whole inland to give an estimate of 377 Kura on Atiu.

Despite our efforts to detect all Kura within 50m, did we miss a few, or many? We considered two alternative methods to compensate for undetected Kura along the transects. In the first alternate method, we accepted only the top two counts for each transect for a total of 128 birds, which upscaled to give an estimate of 483 Kura on Atiu.

The second alternate method, based on experiments by island resident Roger Malcolm, applied a factor to allow for the proportion of time Kura are silent and likely to be undetected. Applying this factor gave a total of 167 birds on the transects, which upscaled to give an estimate of 630 Kura on Atiu.

Was it reasonable to upscale the number of Kura on our eight transects to apply to the whole inland? We concluded this was reasonable because the road transects were long and widespread, which we thought gave a fair representation of the different habitats of the entire inland. Furthermore, the transects covered more than a quarter of the whole inland, which was a relatively large sample.

In considering the estimates of 380, 480 and 630 Kura on Atiu we settled on the most conservative value of 380, noting that even this value showed the Kura had bred very successfully on Atiu.

The four birds inspected by the veterinarian were in excellent health with no diseases or parasites.

Mitiaro after 10 years

Within two months of the 2007 reintroduction, four Kura flew from Atiu to Mitiaro. Unfortunately, Mitiaro was known to have ship rats, which had been lethal to the Ultramarine Lorikeet in the Marquesas and the Blue Lorikeet in the Tuamotus. Could the Rimatara Lorikeet cope with these rats?

In January this year Natural Heritage lead a team to undertake a Kura census on Mitiaro. The team was made up of Roger and Kura Malcolm, Elaina Bufano, and Olaf Rasmussen of Ridge-to-Reef.

Our road-transects completely covered the four central foodland areas. We surveyed them all on Tuesday, Wednesday and Thursday mornings and did not hear or see a single Kura.

In contrast, the household survey by Kura Malcolm and Elaina Bufano revealed a few instances of up to three Kura being seen in recent times.

On Thursday Maara Teuira showed us where he had seen a Kura on Auta foodland in the morning, and in the afternoon workers in the Auta taro swamp reported seeing one to three Kura on three mornings since Monday. Were all these sightings real, or a tease?

On Friday morning the team was out in force on Auta around the taro area and where Maara had seen his bird. And, of course, we did not see the three Kura. However, Roger Malcolm did glimpse one in the same area that Maara saw his bird the previous morning.

The scoreboard for the number of Kura on Mitiaro was: households three; taro workers three; and Natural Heritage team one.

We concluded Mitiaro had three Kura, which showed that the four Atiu runaways had failed to breed.

In conclusion, the 10-year assessment showed that the Kura reintroduction to Atiu was a great success. In contrast, the unintended experiment on Mitiaro showed that rats prevented the Kura from breeding, confirming the original reason for establishing a second population on an island free of ship rats.

The Trust thanks Ridge-2-Reef and Air Rarotonga for their support.