||Ducula aurorae (Peale, 1848)
||Polynesian Imperial-pigeon, Polynesian Imperial Pigeon, Polynesian Imperial-Pigeon, Society Islands Pigeon
||del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
||51 cm. Large, knob-billed pigeon with broad rounded wings. Silver-grey head and most of underparts, dark bronzy-green upperparts, black undertail-coverts. Similar spp. Feral pigeon Columba livia much smaller and does not live in forests. Voice Gruff, hoarse rouw-rouw-rouw and variety of quieter notes.
|Red List Category & Criteria:
||Blanvillain, C., Ghestemme, T., Kesler, D., Raust, P. & Thibault, J.
||Derhé, M., Mahood, S., O'Brien, A., Shutes, S., Stattersfield, A., Symes, A., Dutson, G., Westrip, J., Wheatley, H.
This species has a small population within a very small range: almost certainly only now occurring on one very small island. Although it may currently be increasing there owing to a cessation of mining activities and hunting, it could decline rapidly in the near future owing to habitat destruction, or if Swamp Harrier Circus approximans colonises the island. Recent surveys suggest that the population size is larger than previously thought, but the imminent threat of a resumption of mining activities on Makatea means that future continuing declines in area of occupancy, area/quality of habitat and population size are likely. Therefore, the species is listed as Endangered, though if these future threats do not materialise the species will warrant downlisting.
|Previously published Red List assessments:|
- 2016 – Endangered (EN)
- 2016 – Endangered (EN)
- 2013 – Endangered (EN)
- 2012 – Endangered (EN)
- 2008 – Endangered (EN)
- 2004 – Endangered (EN)
- 2000 – Endangered (EN)
- 1996 – Vulnerable (VU)
- 1994 – Vulnerable (VU)
- 1988 – Threatened (T)
Ducula aurorae is known from Tahiti in the Society Islands and Makatea in the Tuamotu Archipelago, French Polynesia. On Tahiti, it may already be extinct, it was restricted to the Papeno`o and Hitia`a valleys in 1986-1990 (Monnet et al. 1993), but none were reported in 1998 and in 2006 it was considered unlikely to persist (Thibault and Cibois 2006). On Makatea, the population was judged to lie between 100 and 500 individuals in 1986-1987, but have since increased following a reduction in hunting (Thibault and Guyot 1987, Thibault and Cibois 2006). A survey on Makatea in 2009 estimated the total population size at 1,206 individuals (95% C. I., 867-1,677) (Albar et al. 2009, 2010). This appears to be a genuine population increase, perhaps related to the cessation of mining activities and reduction of the human population on Makatea. There are also fossil records indicating that it was once more widespread, including in the Southern Cook Islands (Steadman 1989).
|♦ Estimated area of occupancy (AOO) - km2:||25||♦ Continuing decline in area of occupancy (AOO):||Yes|
|♦ Extreme fluctuations in area of occupancy (AOO):||No||♦ Estimated extent of occurrence (EOO) - km2:||28|
|♦ Continuing decline in extent of occurrence (EOO):||Unknown||♦ Extreme fluctuations in extent of occurrence (EOO):||No|
|♦ Number of Locations:||2-5||♦ Continuing decline in number of locations:||Unknown|
|♦ Extreme fluctuations in the number of locations:||No|
|♦ Upper elevation limit (metres):||1100|
|Range Map:||Click here to open the map viewer and explore range.|
On Makatea, much of its habitat was destroyed during the period 1917-1964 as a result of phosphate mining, however it is now spreading as vegetation recovers and hunting is reduced (Thibault and Guyot 1987, P. Raust in litt. 1999, Thibault and Cibois 2006, Albar et al. 2009, 2010). However, Makatea is being considered for new mining activities, which may further affect the birds (Albar et al. 2010), and there is a high chance mining could restart in the near future (C. Blanvillain, T. Ghestemme and P. Raust in litt. 2017). A proposed runway and associated road and infrastructure development is likely to lead to renewed deforestation (Thibault and Cibois 2006). Predation by introduced cats and rats (particularly black rat Rattus rattus) may be a problem (Monnet et al. 1993), although the species has coexisted with rats for several decades (J.-C. Thibault in litt. 2000). On Moorea, Tahiti and other formerly inhabited islands, its extinction may have been the consequence of the spread through the Society Islands of the Swamp Harrier Circus approximans (Holyoak and Thibault 1984, Thibault 1988, Seitre and Seitre 1991, Thibault and Cibois 2006). This species continues to spread throughout the region, and its arrival on Makatea would be disastrous for D. aurorae (Thibault and Cibois 2006).