Justification of Red List Category
This species qualifies as Vulnerable because it is restricted to low-lying forest in a region in which this habitat-type is being cleared and degraded at such a rate that rapid and continuing population declines are suspected.
The population size is preliminarily estimated to fall into the band 10,000-19,999 mature individuals. This equates to 15,000-29,999 individuals in total, rounded here to 15,000-30,000 individuals.
Rates of forest loss in the Sundaic lowlands have been extremely rapid (Kalimantan lost nearly 25% of its evergreen forest during 1985-1997, and Sumatra lost almost 30% of its 1985 cover), because of a variety of factors, including the escalation of illegal but corruptly promoted logging and land conversion, with deliberate targeting of all remaining stands of valuable timber including those inside protected areas, plus forest fires (particularly in 1997-1998).
Treron capellei occurs from peninsular Thailand and Peninsular Malaysia to Borneo (including Brunei, Sabah and Sarawak, Malaysia, and Kalimantan, Indonesia), and the Indonesian island of Sumatra (BirdLife International 2001). It was once widely distributed and at least locally very common, but serious declines have taken place, such that it is now highly local and scarce. There are no recent records from Myanmar or Java. In the early twentieth century, flocks of 200–300 birds were reported as normal in Peninsular Malaysia (BirdLife International 2001). Regular flocks of 20-30 birds in Taman Negara, and reports that it remains locally common in Belum Temenggor, suggest that sizable populations may still persist within large forest blocks in Malaysia (Yeap Chin Aik in litt. 2007, Iqbal et al. 2012). The species was absent from several recent surveys in Kalimantan (eg. Meier 2005, Brickle et al. 2010, Sheldon et al. 2010), or recorded in small numbers (Slik and Balen 2006, Wielstra and Pieterse 2009, Wielstra et al. 2011, Woxvold and Noske 2011, Wielstra et al. 2012). However, 48 birds were reported roosting on the edge of secondary forest in East Kalimantan in November 2011 and up to 25 were seen at a logging concession in Melawi district, west Kalimantan in March 2011 (Iqbal et al. in press). At least 50 birds were observed inside the Danum Valley conservation area, Sabah in May 2009 (Iqbal et al. 2012). Little is known about its status on Sumatra, however, a flock of more than 40 birds was observed at Way Kambas National Park in May 2006 (Iqbal and Iqbal 2012).
It inhabits primary and logged evergreen rainforest, almost exclusively in the lowlands, rarely ascending foothills to 1,500 m. Small flocks visit fruiting trees (usually figs Ficus spp.) and are generally encountered high in the canopy. It is largely sedentary, although populations may fluctuate in response to fruiting cycles, and nocturnal movements have been noted.
Massive declines in the population of this species are presumably occurring in the face of habitat loss. Huge areas of lowland forest were removed from its range during the 20th century, chiefly through logging, conversion to agriculture and fire. For example, Kalimantan lost almost 25% of its cover between 1985 and 1997, and Sumatra lost 30% in the same period, suggesting that virtually all original lowland habitat may disappear in the near future, unless preventative measures can be implemented effectively. A similar scenario faces all other range states. Major fires in Borneo and Sumatra continue to affect enormous areas of forest while industrial-scale illegal logging is rampant in almost all protected areas. A secondary threat is imposed by widespread high levels of hunting.
Conservation Actions Underway
It has been recorded in several protected areas, including Taman Negara (Malaysia), Gunung Palung and Tanjung Puting National Parks (Kalimantan), Gunung Leuser and Bukit Barisan Selatan National Parks (Sumatra), and Gunung Mulu (Sarawak).
36 cm. Large, arboreal pigeon. Male is generally greyish-green, paler below, with dark golden patch on chest, blackish-grey wings, fringed yellow. Undertail-coverts dark chestnut. Yellow legs. Female has yellow chest patch. Similar spp. Female Thick-billed Green-pigeon T. curvirostra is smaller, lacks coloured patch on chest, undertail-coverts green-and-white, legs reddish. Voice Deep, rich growling notes and kak-kak or kwok-kwok.
Text account compilers
Benstead, P., Bird, J., Butchart, S., Taylor, J., Tobias, J., Martin, R, North, A.
Davison, G., Aik, Y.
BirdLife International (2021) Species factsheet: Treron capellei. Downloaded from http://www.birdlife.org on 23/10/2021. Recommended citation for factsheets for more than one species: BirdLife International (2021) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 23/10/2021.