Justification of Red List Category
This wide-ranging species is rarely encountered but is assumed to have a small population that is declining through forest loss. Its confiding behaviour, flocking habits, specialised food requirements and nomadic nature make it susceptible to hunting. Information from at least one site, Hauta, suggests that the population may be declining rapidly. These factors together qualify it as Vulnerable.
The population is estimated to number 1,000-2,499 individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 667-1,666 mature individuals, rounded here to 600-1,700 mature individuals.
The species is suspected to be declining rapidly owing to habitat loss and hunting.
Ducula brenchleyi is endemic to Guadalcanal, Malaita and Makira (= San Cristobal), including the satellite islands of Ulawa, Ugi (= Uki Ni Masi) and Three Sisters, Solomon Islands. On Guadalcanal, an expedition in 1953 failed to find it (Cain and Galbraith 1956) and there are few recent records (G. Dutson pers. obs. 1997-8, K. D. Bishop in litt. 1999). Hunters at Komarindi report shooting just one of this species for every 20 D. rubricera (van Oosten and Wyant 1999). On the little-studied island of Malaita, it is known from just one specimen and was seen twice in 1990 (Mayr 1931, Lees 1991, P. Scofield in litt. 1999). On Makira, it was recorded as common from coastal to ridge forest in 1953 (Cain and Galbraith 1956). More recent records include single birds and congregations of up to 20 birds around Hauta (Lees 1991, Buckingham et al. 1995, Gibbs 1996, G. Dutson pers. obs. 1997-8, R. James in litt. 1999) . On Ugi and Ulawa, it was recorded as abundant in 1953 (Cain and Galbraith 1956), but there have been no recent records there or on the Three Sisters, and it may be extinct on these small islands (G. Dutson pers. obs. 1997-8).
It is usually recorded in primary forest but also occurs in fruiting trees in degraded forest and gardens (Cain and Galbraith 1956, Buckingham et al. 1995, R. James in litt. 1999). Recent records have been from sea-level to 700 m, but has been reported by local villagers on Guadalcanal as occurring in mist-forest (Cain and Galbraith 1956, Buckingham et al. 1995). It appears to be nomadic (G. Dutson pers. obs. 1997-8, J. Waihuru verbally 1998, R. James in litt. 1999): at Hauta, birds congregate to feed on banyan figs for about a week until the fruit is finished and then disperse, often over large distances (Cain and Galbraith 1956, J. Waihuru verbally 1998, R. James in litt. 1999).
This large pigeon is hunted by villagers around Hauta and elsewhere across its range. Forest is being degraded through logging activities and pressure on land for cultivation is a problem on the over-populated island of Malaita. Rate of forest loss has increased in recent years on the Solomon Islands (G. Dutson in litt. 2007), and this may particularly affect this species due to its reliance on fruiting trees.
Forest degradation has been accelerating across the Solomons and, particularly on Guadalcanal, prime habitat for this species has been severely altered by logging (west Guadalcanal has lost most of its intact low and mid elevation forest in the last 5 years [G. Dutson in litt. 2016]). Hunting pressure on the other hand has likely declined across most of the range of this species, and though surely a threat, a gun ban in 2003 seems to have allowed the species to rebound, with many more birds seen in the coastal lowlands of Makira than previous years (G. Dutson in litt. 2016).
Conservation Actions Underway
The effects of hunting pressure and the foraging behaviour of large pigeons has been studied briefly at Hauta. The forests around Hauta are part of an integrated conservation and development programme (R. James in litt. 1999). Community-based education programmes have started around Komarindi (van Oosten and Wyant 1999).
38 cm. Large, dark, slender imperial-pigeon. Dark grey above shading into pale grey on head. Dark vinous underparts, becoming chestnut on belly to undertail-coverts. In flight, grey with contrasting chestnut underwing-coverts. Similar spp. Island Imperial-pigeon D. pistrinaria is pale grey with paler spectacles, green-grey upperparts and chestnut only on the undertail-coverts. Yellow-legged Pigeon Columba pallidiceps has pale head, glossy black body and yellow legs. Voice Deep, smooth, prolonged coo, rising in pitch then falling ooloooo. Hints Usually seen flying overhead or in mixed pigeon flocks (often with Red-knobbed Imperial-pigeon D. rubricera and D. pistrinaria) in fruiting trees.
Text account compilers
Derhé, M., Dutson, G., Ekstrom, J., Mahood, S. & Stattersfield, A.
Bishop, K., Dutson, G., James, R., Scofield, P. & Waihuru, J.
BirdLife International (2019) Species factsheet: Ducula brenchleyi. Downloaded from http://www.birdlife.org on 14/11/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 14/11/2019.