Search the SPREP Catalogue

The restoration of the small offshore islands of Nu’utele (108ha) and Nu’ulua (25ha) has long been identified as a priority for biodiversity conservation in Samoa. The first step towards restoration was the aerial spreading of brodifacoum to eradicate Pacific rats (Rattus exulans) in August 2009. Procedures for the eradication followed those used in New Zealand and involved technical experts from that country. Particular challenges included a tight operational time-frame (two months), technical problems magnified by the remote location, variable reliability of weather forecasting,working with the local community, and mitigating rodenticide exposure risks for the friendly ground-dove (Gallicolumba stairi) (IUCN: vulnerable). Solutions to these challenges are discussed as guidance for similar projects in remote island locations. Follow-up monitoring between August 2009 and March 2010 indicated that the eradication had been successful, but Pacific rats were detected on Nu’utele in May 2011. Nu’ulua has yet to be rechecked in 2011. DNA analyses are being organised to determine if these rats are survivors or re-invaders.

During 10–21 September, quantitative surveys were carried out of birds and flying foxes using the same techniques as applied in earlier surveys, and searches carried out for a rare parrot and lizard. Bird counts showed that the lupe or Pacific imperial-pigeon population has recovered following a decline between 1994 and 2004 though the current hunting rate is considered unsustainable. Miti or Polynesian starling numbers have gradually declined over the period 1994–2012 which is a concern and hard to explain. Rat predation is a possible cause. There was also an indication that pekapeka or white-rumped swiftlet numbers have declined though more investigation is needed to confirm this. We were unable to find any hega or blue-crowned lory though a few individuals were reported to us. Numbers are clearly very low and the next step must be to gain a better understanding of where the species regularly occurs so that management can be applied

During 10–21 September, quantitative surveys were carried out of birds and flying foxes using the same techniques as applied in earlier surveys, and searches carried out for a rare parrot and lizard. Bird counts showed that the lupe or Pacific imperial-pigeon population has recovered following a decline between 1994 and 2004 though the current hunting rate is considered unsustainable. Miti or Polynesian starling numbers have gradually declined over the period 1994–2012 which is a concern and hard to explain. Rat predation is a possible cause. There was also an indication that pekapeka or white-rumped swiftlet numbers have declined though more investigation is needed to confirm this. We were unable to find any hega or blue-crowned lory though a few individuals were reported to us. Numbers are clearly very low and the next step must be to gain a better understanding of where the species regularly occurs so that management can be applied.

For one of the species potentially at some risk of poisoning under the proposed rat eradication regime, the Friendly Ground Dove, Nuutele and Nuulua hold populations that are nationally significant. The complete loss of these populations would threaten the survival of the taxon in Samoa. Some authors consider the Samoan doves to be a separate race (Gallicolumba s. stairi) from those in Fiji and Tonga (Watling, 2001). Outside Samoa, the race is only found on the small island of Ofu, American Samoa where it is threatened. So the loss of Nu’utele and Nu'ulua birds could threaten the race with extinction.

On 6 January 2004. cyclone Heta devastated much of the South Pacific island nation of Niue. Extensive damage was done to forest, particularly of the north- western sector, with many trees up-rooted and others stripped of branches and foliage. This report details our findings from a survey of Niue's birds and rodents during 3-19 September 2004 and compares these with results from a similar survey in September 1994. Five-minute bird count data, an index of conspicuousness, from three transects showed that heahea (Polynesian triller,Lalagc maculosa) were more abundant in 2004 than in 1994, but mid (Polynesian starling, Aplonis tabuensis), kulukulu (purple-crowned fruit dove. Ptilinopus porpbyraecus) and lupe (Pacific pigeon. Ducula pacifica) had declined. The 28-64% decline in the lupe population per transect w as probably primarily as a result of hunting, rather than mortality caused by cyclone Heta. Counts of birds seen per kilometre along three sections of road (lower, upper, inland) were also compared with September 1994 data. However, for various reasons we doubt that the results accurately reflect population numbers. The 212 kiu (Pacific golden plover. Pluvial is fulva) counted at sites accessible from main roads in September 2004 was similar to the 226 seen in September 1994. Rat trapping results (captures per 100 trap-nights) along the same three transects for December 1994 and September 2004 were not significantly different. Both kuma (Pacific rat. Rattus exulans) and ship rats (R. rattus) were trapped, but kuma were found only in regenerating scrub, whereas ship rats were present in both scrub and forest. Recommendations for future work are made mainly in relation to the long-term conservation of lupe, a toaga (treasured) species of Niueans.

Between 1892 and 1930, 58 percent (30 taxa) of Hawaiian endemic forest birds either were greatly reduced or became extinct. The order in which the islands experienced major declines ofseveral forest birds is Oahu (ca. 1873-1887), Hawaii (1892-1900), Mo10kai (1893-1907), Maui (18941901), Kauai (after 1900), and Lanai (1926-1932). Loss of habitat, reduced food supply, introduced avian diseases, as well as predation by man, feral cats, mongooses, and Norway rats (Rattus norvegicus) all appear to have reduced some species ofbirds, but none ofthese factors adequately explains the accelerated rates ofdecline offorest birds that occurred after 1892. Although it has been assumed that roofrats (Rattus rattus) reached Hawaii with the first European ships at the end of the 18th century, there is circumstantial evidence, independent of the bird decline data, that indicates that this rat did not arrive until after 1840, probably between 1870 and 1880. The hypothesis is advanced that after its establishment on Oahu in the 1870s, R. rattus spread to the remaining large islands in the group, resulting in a stepwise accelerated decline offorest birds on each island in turn. Hawaii thus parallels some other Pacific islands where major reductions of birds have followed the establishment of R. rattus. The need for precautions to prevent rats from reaching rat-free islands in the Hawaiian group is emphasized.