Justification of Red List Category
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.
The population is estimated to number about 200 individuals, roughly equating to 150 mature individuals.
The various subpopulations have fluctuated in recent years and the overall trend is precautionarily assessed as declining.
The species occurs in the Tuamotu Archipelago, French Polynesia, where there have been recent records from Rangiroa (in the NW), Morane and from the Acteon Group islands of Matureivavao, Vahanga, Tenarunga and Tenararo and (in the SE). The species formerly occurred in the Society Islands and throughout the Tuamotu Archipelago (in 1923, the species was observed in 23 islands) and there are fossil records from the Southern Cook Islands (Steadman 1989). Race erythropterus is known from Tahiti and Moorea in the Society Islands (now extinct) and from the southern Acteon Group in eastern Tuamotu, while race albicollis is known from central and northern Tuamotu (Holyoak and Thibault 1984). No birds were observed in Tuanake and Hiti in 2000 (Blanvillain et al. 2002) and a survey in central Tuamotu around Fakarava found no new new populations (Falquier 2014).
12-20 individuals were recorded in two forested islets in Rangiroa Atoll in 1990-1991 (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 nine doves in the atoll, including one male on the rat-free island (Gouni et al. 2005, Raust et al. 2006). During field surveys from 2008 to 2012, up to 12 individuals were captured and banded on Rangiroa (Albar 2011, Ghestemme 2012). In 2013, three females and five males were still present and a young male was caught and banded, but one male and one female had symptoms of avian pox (T. Ghestemme in Blanvillain et al. 2015). In 2014, only four adult males were present, and in 2015, only two males were observed (Blanvillain et al. 2015).
A 2003 expedition discovered a new population of 10-30 birds on Morane (Pierce et al. 2003). However, surveys on Morane over three days in June 2012 found just two individuals, suggesting that the population there may be smaller than ten birds (Anon. 2012, Ghestemme et al. 2012).
In 1999-2002, a small population estimated at 50 (36-70) birds was found on Tenararo, but no populations other than occasional individuals believed to be dispersals from the main island, were found on a further seven islands (C. Blanvillain in litt. 1999, Blanvillain et al. 2002). In Matureivavao, the species was 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). Small numbers (up to four) were seen during visits to Vahanga in 2000-2007 (Blanvillain et al. 2002, Griffiths et al. 2008). In 2015, a healthy population of 190 (160-240) (130-150 birds on Tenararo, 5+ on Vahanga and two on Tenarunga) was found in the Acteon Group plus several small populations (probably visitors trying to establish themselves) on surrounding islands (Blanvillain et al. 2016, Pierce et al. 2016). It was suspected that if other Acteon Group islands are successfully eradicated of predators, they could support additional populations, but initial eradication attempts failed in 2003 (Blanvillain et al. 2003). A second eradication attempt on two islands of the Acteon Group and four other island and islets of eastern Tuamotu and Gambier archipelago has been implemented with unknown results.
It favours primary forest of Pandanus tectorius and Pisonia grandis on atolls with herbs, shrubs and ferns or dense shrubs, and has been observed in dense shrubs under coconut trees (planted in 1977 and never managed or harvested) (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, Pierce et al. 2015,16). A key food in 2005 was seeds of Achyranthes aspersa (Pierce et al. 2005). The first nest discovered was in a Pandanus tree (Ghestemme 2012, Grassi 2013).
The greatest current threat to this species are rat invasion of islands in the Acteon Group and southern Tuamotu that are currently rodent-free, or re-invasion of islands that are currently being cleared of rats. Black Rats Rattus rattus are the great threat but Pacific Rat Rattus exulans can probably extirpate the species from small islands (Gouni et al. 2004, 2005, 2007, Blanvillain et al. 2003). 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. Other invasion risks include from cats and invasive ants, e.g. yellow crazy ant is extending its range in Tuamotu-Gambier (Pierce et al. 2016). On Vahanga the invasive plant Lantana out competes native plants that the species feeds on (Hurrell 2015b), and has been the object of an eradication attempt in 2015. The extinction of the Rangiroa population coincided with the discovery of avian pox symptoms. Avian malaria has impacted on the Rangiroa population (Blanvillain et al. 2014). Habitat threats include habitat degradation from the aggressive colonisation of islands by coconuts resulting in the depletion of indigenous plant foods. Added to this are higher sea-levels and associated greater impacts of storms and tidal surges on plant habitats. The species was formerly hunted by local people for food (Holyoak & Thibault 1984).
Conservation Actions Underway
An island restoration project from 2015-2017 removed rats and other invasive species (including the invasive plant Lantana) from six islands in the Acteon group and Gambier archipelagos (Vahanga, Tenarunga, Temoe, Kamaka, Makaroa and Manui; Hurrell 2015c, LPO 2017). These operations built on previous work and recommendations including successful rat eradications completed on a few motu located in the south of Rangiroa atoll (Faulquier 2009) and others have been proposed within a 2010 feasibility study (Champeau et al. 2010). Agreement has been obtained to rent two Rangiroa islets (including Motu Omai) for protection of the species and future rat eradications (Grassi 2013).
Expeditions in 1999, 2003 and 2012 surveyed eight islands of the central and eastern Tuamotu (Blanvillain et al. 2002, Pierce et al. 2003, Pierce et al. 2016). Follow-up work, including further surveys, rat eradication and captive breeding, took place in 2001 and 2002 (Blanvillain et al. 2003). SOP-Manu continue to raise awareness through education and signage; providing 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 Acteon Group; colour-ring the population of Rangiroa and undertake enhanced monitoring to assess productivity and adult survival and work to develop a Site Support Group (SSG). None remain in captivity in Tahiti. A field survey to assess the population in Morane and the Acteon Group took place in 2012 (Ghestemme et al. 2012). A public awareness campaign took place on Rangiroa in 2012, along with experimental supplementary feeding (Ghestemme 2012). Species action plans have been developed for 2013-2017 (Grassi 2013) and 2016- 2020 (Pierce et al. 2016).
Conservation Actions Proposed
Implement actions identified in the Species Action Plan (Pierce et al. 2016) spanning monitoring of populations every 3-15 years; strengthen biosecurity measures on all islands, staging islands and vessels; identify suitable islands in the Acteon group and beyond for translocation; manage habitat quality in Acteon Group; research threats and implement more awareness raising including gaining the support of local people for biosecurity and pest eradications. Study the remaining wild population on Acteon group, e.g. feeding and breeding behaviour (C. Blanvillain in litt. 1999, Blanvillain et al. 2002).
25 cm. Medium-sized, short-tailed, ground-dwelling dove. Male of nominate erythroptera mostly dark grey, with white throat, chest, forehead, and eyebrow. Reddish-purple upper back, scapulars and shoulders. Female dark grey with paler grey head, off-white forehead, eyebrow and face and rufous chest with paler feather edges. Male of race albicollis has entirely white head and neck. Voice Low moan.
Text account compilers
Harding, M., O'Brien, A., Shutes, S., Bird, J., Stattersfield, A., Symes, A., Taylor, J., Wheatley, H., Ashpole, J, Butchart, S., Derhé, M., Dutson, G.
Blanvillain, C., Cranwell, S., Faulquier, L., Gouni, A., Pierce, R. & Raust, P.
BirdLife International (2021) Species factsheet: Alopecoenas erythropterus. Downloaded from http://www.birdlife.org on 16/01/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 16/01/2021.