| Citation |
BirdLife International. 2016. Ptilinopus arcanus. The IUCN Red List of Threatened Species 2016: e.T22691568A93316693. https://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T22691568A93316693.en. Accessed on 04 May 2022. Brinkman, J.J., van der Ven, W., Allen, D., Hutchinson, R., Jensen, A.E., Perez, C. (2021): Checklist of birds of the Philippines. Wild Bird Club of the Philippines. www.birdwatch.ph |
Description |
JUSTIFICATION
This species has not been recorded since the type specimen was collected in 1953, despite a number of recent protracted surveys. However, it may remain extant, given that there was an unconfirmed report in 2002, and given the shyness of fruit-doves. Further surveys are required on Panay where it may conceivably occur. Any remaining population is likely to be tiny, and undergoing a continuing decline owing to hunting and extensive habitat destruction. For these reasons, it is listed as Critically Endangered.
RANGE DESCRIPTION
Ptilinopus arcanus is endemic to the Philippines, where it is known only by a single female specimen (one of a pair) collected on Mt Canlaon on the island of Negros in 1953 (Collar et al. 1999). Its population is unknown and, given the failure of any fieldworker to encounter it since its discovery, it must be extremely rare. However, the recent discovery on Panay of threatened species which, until 1990, were known only from Negros, and sometimes formerly Guimaras (e.g. Negros Bleeding-heart Gallicolomba keayi and White-throated Jungle-flycatcher Rhinomyias albigularis), suggests that it is not impossible that this enigmatic bird may be extant. Three birds that fit the speciess description were reportedly shot by hunters in 1985 and 2008 in Mantiquil and near Mt Canlaon respectively (Collar and Lambert 2013). Fruit-doves in the Philippines are extremely shy, thus it is quite possible that even on Negros this species might be overlooked, and the extensive forests of Panay which have yet to be surveyed by experienced field-workers might harbour the species (R. Hutchinson in litt. 2013).
DESCRIPTION
The population is assumed to be tiny (fewer than 50 individuals and mature individuals) based on a lack of records since the only specimen was collected in 1953.
Trend Justification: Although this species and its habitat requirements are incredibly poorly known, it seems likely that - if it is still extant - its population is decreasing in line with habitat loss and degradation within its range.
HABITAT AND ECOLOGY
The specimen was shot in a tall fruiting tree in primary forest at c. 1,100 m. It is possible that it is a lowland specialist discovered at its upper altitudinal limit (as forest at this site had been cleared up to 1,000 m).
THREATS
A combination of hunting, which affects all pigeons and fruit-doves on Negros, and habitat destruction are presumably the major threats. Just 4% of Negros remained forested in 1988, and remnant tracts are small, heavily fragmented and under incessant pressure from clearance for agriculture, timber and charcoal-burning.
CONSERVATION ACTIONS
Conservation Actions Underway
The only record derives from Mt Canlaon Natural Park, which supports 115 km2 of mainly montane forest. Surveys in 1991, 1994 and more recently in 2010 failed to find the species (Collar and Lambert 2013). However the 2010 survey found that suitable forest patches remain in the area and larger pigeon species can still be found despite heavy hunting pressure. No other conservation measures are known to have been taken other than its depiction in the mid-1990s on a bilingual environmental education poster in the "Only in the Philippines" series.
Conservation Actions Proposed
Comprehensive and targeted surveys are required, using sound recording equipment (D. Allen in litt. 2012), within all suitable lowland to mid-montane habitat on Negros and Panay, to determine if this species is still extant. Carry out, if possible, biochemical analyses on the type-specimen to confirm its taxonomic validity. Increase the area of suitable habitat on Negros and Panay that receives formal protection. Monitor habitat trends on Negros and Panay through remote sensing. |
