Justification of Red List category
This species has a very small population, on two tiny islands, numbering less than 250 mature individuals. As a direct result of conservation action on Nuku Hiva and the translocation of birds to Ua Huka, the population is increasing slowly overall, but the population remains small and thus qualifies as Endangered.
Population justification
In 1998, a maximum of 85 birds were seen on Nuku Hiva and the population was estimated at c.250 (Evva 1998). The population was estimated at 265 individuals in the most recent surveys (Thibault and Cibois 2017). Successful reintroductions of birds in 2000 and 2003 to Ua Huka resulted in a new population rapidly increasing to several tens, though further surveys are needed to quantify the current population size (C. Blanvillain in litt. 2016, Thibault and Cibois 2017). The total population is thus estimated to number at least 300 individuals, roughly equivalent to 200 mature individuals (C. Blanvillain in litt. 2016). It is here placed in the range 200-249 mature individuals.
Trend justification
Surveys indicate range expansion during the 2000-10s and the trend may be continuing to increase due to a decrease in poaching and an increase in tourism-related interest in this species (Thibault and Cibois 2017). Communication surrounding the reintroduction operation has allowed the population on Nuku Hiva to increase to well over 200 individuals, and the species is reportedly easy to locate in places where it was absent before, including near habitations (C. Blanvillain in litt. 2016, Blanvillain 2019). The translocated population on Ua Huka may be slowly increasing; it increased by 28% in the 2005-2006 season and reached 46 individuals in 2008 (Gouni et al. 2008, Gouni et al. 2011). Visits to the island in 2010 and 2012 reported a number of individuals and several nests (Champeau 2010), though further surveys are needed.
Ducula galeata is endemic to the Marquesas Islands and until 2000 was only known from Nuku Hiva, French Polynesia, where it was restricted to valleys in the west and north of the island, though more recently there have been observations of the species in the central south of the island (Anon 2011) and near human inhabitations (C. Blanvillain in litt. 2016). Following successful reintroductions of birds in 2000 and 2003 there is now an established population on Ua Huka.
It is an arboreal species found in remote wooded valleys, recorded from the shore to the upper ridges (Thibault and Cibois 2017), and is also seen in secondary forest and at the edge of banana and orange plantations (Holyoak and Thibault 1984). It feeds on fruit from native and introduced trees and shrubs, including large quantities of guava Psidium guajava (Pratt et al. 1987). It only lays one egg suggesting that it is long lived and any population increases would be slow and unclear for several years (Villard et al. 2000).
Intensive hunting was primarily responsible for this species' disappearance from islands in its former range. However, this appears to have been reduced following an awareness raising campaign surrounding the reintroduction of birds to Ua Huka in 2000 and 2003. Islanders were previously unaware that Nuku Hiva was the species' last refuge and consequently poaching has decreased; this has since allowed the population to increase to over 200 individuals and hunting is thus not currently thought to be driving significant declines (Blanvillain 2019). Nevertheless, poaching has the potential to rapidly reduce the population as it has done so in the past, and remains a potential threat (Gouni 2006). Suitable habitat has been lost in the past due to deforestation for pasture and pine plantations (Villard et al. 2003). Habitat has been modified and degraded by introduced vegetation and grazing by feral stock (Seitre and Seitre 1991, 1992, Evva 1998), and this is ongoing. Habitat quality is affected by introduced plant species including Miconia calvescens, which may became a major problem in future because of its high potential of rapid habitat degradation, and pines Pinus sp. that are progressively invading the forest, as well as regular fires (C. Blanvillain in litt. 2016). Introduced cats Felis catus, pigs Sus scrofa, goats Capra hircus, cattle Bos taurus and rats Rattus spp. are all common on Nuku Hiva and likely constitute a threat (Seitre and Seitre 1991, 1992; Blanvillain and Thorsen 2003). The parasite Plasmodium relictum is present, and diseases dispersed by exotic bird species may be a threat (C. Blanvillain in litt. 2016).
Conservation Actions Underway
Following recommendations of translocations (SPREP 1999), five birds were released on Ua Huka. At least four of the five introduced birds had survived into June (Blanvillain et al. 2000), and in 2003, five more birds were released to augment the population. Following a 28% increase in this population during the 2005/2006 season, the population reached 46 individuals in 2008 (Gouni et al. 2008, Blanvillain et al. 2011). A visit to the island in 2010 reported a number of individuals and several nests (Champeau 2010). In 2012, 26 birds were relocated to two uninhabited valleys (Blanvillain et al. 2012). An awareness raising campaign focused initially on local school children has met with success and it has now been expanded to the general public, and as a result hunting pressure appears to have been reduced (Gouni 2006, Blanvillain 2019). Thanks to lobbying by Manu a road development project was amended and the new road and tunnel project cancelled - only rehabilitation of the actual road was carried out (A. Gouni in litt. 2007). Nuku Hiva islanders are trying to reduce the Miconia calvescens invasion but eradication seems unlikely (C. Blanvillain in litt. 2016).
55 cm. Very large, broad-winged pigeon with expanded cere flattened dorso-ventrally, making bill look duck-like at distance. Mostly dark slate-grey with bronze-green reflections on upperparts. Rufous-chestnut undertail-coverts. White eyes. Voice Deep bellow waah-waah, like the mooing of a cow.
Text account compilers
Vine, J.
Contributors
Gouni, A., Raust, P. & Blanvillain, C.
Recommended citation
BirdLife International (2024) Species factsheet: Nuku Hiva Imperial Pigeon Ducula galeata. Downloaded from
https://datazone.birdlife.org/species/factsheet/nuku-hiva-imperial-pigeon-ducula-galeata on 24/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from
https://datazone.birdlife.org/species/search on 24/12/2024.