|Scientific Name:||Gallicolumba erythroptera|
|Species Authority:||(Gmelin, 1789)|
|Red List Category & Criteria:||Critically Endangered C2a(i) ver 3.1|
|Reviewer/s:||Butchart, S. & Symes, A.|
|Contributor/s:||Blanvillain, C., Faulquier, L., Gouni, A. & Raust, P.|
This species has a very small population, fragmented into extremely small subpopulations, on tiny wooded islets. Its extinction from several islands indicates an overall decline, which is likely to continue owing to predation by rats and cats, habitat loss and deterioration, and natural disasters such as cyclones and severe storms. For these reasons it qualifies as Critically Endangered.
Gallicolumba erythroptera formerly occurred in the Society Islands and throughout the Tuamotu Archipelago, French Polynesia. There are also fossil records from the Southern Cook Islands (Steadman 1989). Race erythroptera is known from Tahiti and Moorea in the Society Islands (now extinct) and from the southern Acteon Group in the Tuamotus, while race pectoralis is known from the central and northern Tuamotus (possibly extinct) (Holyoak and Thibault 1984). Recent records include Matureivavao (not numerous in 1968, apparently surviving in 1987 according to local people, but not found in 1999) (C. Blanvillain in litt. 1999, Blanvillain et al. 2002) and two forested islets in Rangiroa Atoll (12-20 birds in 1990-1991, with 11 there in 2010; perhaps a separate subspecies or colour morph of pectoralis [Monnet et al. 1993a]). In 2005, a rat eradication was conducted on one of Rangiroa's motus (small islands) and follow-up surveys in 2006 found 9 doves in the atoll, including one male on the rat-free island (Gouni et al. 2005, Raust et al. 2006). In 2007, 2008, 2009 and 2010 further expeditions to Rangiroa took place to assess the impact of rat eradication efforts, carry out further eradication work and survey for the species (Albar et al. 2009, 2010, Champeau et al. 2010); it is hoped that the species's population occurring on these small islands will begin to expand (Gouni et al. 2005, 2007). During field surveys from 2008 to 2011, 12 individuals were captured and banded on Rangiroa. In 2011, 9 individuals were confirmed on this atoll (Albar 2011). In 1999, a small population (estimated at 16-30 birds) was found on Tenararo, but it was not seen during surveys on a further seven islands (C. Blanvillain in litt. 1999, Blanvillain et al. 2002). A 2003 expedition to remote islands in the Tuamotu archipelago found a population of 50 birds on Tenararo and discovered a new population of 50 birds on Morane, doubling the known global population to around 100-120 birds (Pierce et al. 2003, Gouni et al. 2005). In 2007, four birds were seen on Vahanga (nearest island from Tenararo) but no nests were discovered (Griffiths et al. 2008). A report by a local inhabitant of a unknown bird on Tikehau atoll, which was suspected to be G. erythroptera, has not yet been confirmed. Is is suspected that if Vahanga Atoll is successfully eradicated of predators, the population could increase from 4 to c. 50 individuals, comparable to that of nearby rat-free Tenararo Atoll which is of a similar size (L. Faulquier and P. Raust in litt. 2012).
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The population is estimated to number 100-200 individuals, roughly equating to 70-130 mature individuals.|
|Habitat and Ecology:||It favours primary forest of Pandanus tectorius and Pisonia grandis on atolls with herbs, shrubs and ferns or dense shrubs (C. Blanvillain in litt. 1999, Blanvillain et al. 2002). It has a varied diet, including caterpillars and other insects, seeds, green leaves, buds and fruit (C. Blanvillain in litt. 1999, Blanvillain et al. 2002). Most recently, it was present in dense shrubs under coconut trees (planted in 1977 and never managed or harvested) (C. Blanvillain in litt. 1999).|
It was formerly caught by local people for food but it is more likely that the introduction of cats and rats, (Black rat Rattus rattus and Pacific rat Rattus exulans), are the real reasons for its decline (Holyoak and Thibault 1984, Gouni et al. 2004, 2005, 2007). Tenararo and Morane are currently free of rats and the likelihood of predator introduction is reduced due to their extreme isolation and the decision by the Catholic church to preserve Morane (P. Raust in litt. 2012). However, rodents are present on several islets or motu within the Rangiroa atoll and eco-tours reach the atolls several times a year, thus posing a potential risk of predator introduction. However,Habitat loss is also likely to have been a factor as the largest atolls with the richest vegetation have been cleared for coconut plantations (Monnet et al. 1993a).
Conservation Actions Underway
Expeditions in June and October 1999 surveyed eight islands of Matureivavao and Tenararo. Follow-up work, including further surveys, rat eradication and captive breeding, took place in 2001. Since then, a successful rat eradications have been completed on a few motu located in the south of Rangiroa atoll (Faulquier 2009) and others have been proposed within a feasibility study that was produced in 2010 by the Société d'Ornithologie de Polynésie "Manu" (Champeau et al. 2010). As part of the BirdLife Preventing Extinctions programme SOP-Manu continue to: update the Species Action Plan; raise awareness through education and signage, provide support for land owners to manage tourist visits in order to prevent rat re-establishment on the rat-free islets of Rangiroa; support and advocate the development of protected areas for Rangiroa, Morane and Tenararo; colour-ring the population and undertake enhanced monitoring to assess productivity and adult survival and work to develop a Site Support Group (SSG). Only a single bird remains in captivity in Tahiti. A field survey to assess the population in Morane and the Acteon group is planned for May 2012, and the eradication of Rattus exulans from Vahanga atoll is planned for 2013 (Pierce et al. 2006).
Conservation Actions Proposed
Conduct further surveys in the central Tuamotus and Acteon group, including showing pictures to local people (C. Blanvillain in litt. 1999, SPREP 1999, Blanvillain et al. 2002). Study the remaining wild population on Tenararo, e.g. feeding and breeding behaviour (C. Blanvillain in litt. 1999, Blanvillain et al. 2002). Protect Tenararo from the introduction of predators (by implementing biosecurity measures) and human disturbance (C. Blanvillain in litt. 1999, Blanvillain et al. 2002). Identify suitable islands in the Acteon group for translocation, either rat- and cat-free or where eradication is possible, and support similar initiatives in Rangiroa atoll (C. Blanvillain in litt. 1999, SPREP 1999, Blanvillain et al. 2002). Gain the support of local people for rat eradication throughout Rangiroa (Albar et al. 2010).
|Citation:||BirdLife International 2012. Gallicolumba erythroptera. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 25 May 2013.|
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