Negros fruit dove

The Negros fruit dove was described in 1955 as Ptilinopus arcanus by Sidney Dillon Ripley and Dioscoro Rabor on the basis of a single female specimen collected by Rabor on May 1, 1953.[2] This specimen, collected near Pula on the slopes of Mount Kanlaon in the Philippines, was shot along with a second bird, presumed to be its mate, which was lost in the undergrowth.[3] The holotype is preserved as a skin by Yale University's Peabody Museum of Natural History.[2][4] The generic name Ptilinopus comes from the Ancient Greek words ptilon "feather," and pous, "foot."[5] The specific name arcanus comes from the Latin word arcānus "secret."[6]

Some authors have suggested that the specimen was either a runt of either the yellow-breasted fruit dove or a Treron pigeon, or a hybrid instead of a unique species; however, these views are generally considered invalid due in part to the distinctiveness of the specimen, particularly in the bare skin around the eye, and no proper evidence has suggested that the Negros fruit dove is an invalid species.[2][3] It is uncertain where the dove should be placed within the genus Ptilinopus as the male's plumage, a key feature used in organizing the Ptilinopus doves, is unknown.[7] It has been suggested that the Negros fruit dove is either most closely related to the black-naped fruit dove or represents an early colonization of the Philippines by the genus that has left no surviving close relatives.[7] It has no known subspecies and is also known as Ripley's fruit dove.[8]

The Negros fruit dove is a small, short-tailed fruit dove. Only the appearance of the adult female is known as the presumed male specimen was lost in the undergrowth. The female is a vivid dark green overall with an ash-grey forehead above an extensive ring of bare yellow skin that surrounds the eye.[9] The greater coverts and tertial feathers have broad yellow fringes that create a narrow, if conspicuous, wingbar when the wing is folded.[10] The throat is white while the vent and undertail coverts are yellow.[8] The bill was black and the feet were a dull purplish-red.[10] The fruit dove is 16.5 cm (6.5 in) long.[8]

The Negros fruit dove is believed to be endemic to the island of Negros in the central part of the Philippines.[8] However, some hope exists that the bird may persist undetected on a nearby island.[8] The only known birds were collected from a forest at the edge of a clearing on Mount Kanlaon at an elevation of about 1,100 m (3,600 ft).[8] The forest was noted as being "halfway between the genuine lowland dipterocarp forest type... and the real mid-mountain forest type."[3] It is suspected that the species preferred habitat at a lower altitude, and that the collected pair may have been driven to higher elevations by deforestation in the lowlands.[8]

The sole sighting of the Negros fruit dove involved a pair of birds seen eating at a fruiting tree.[8] No other information is known about its behavior.[10]

Mount Kanlaon

The species has not been recorded since the original pair of Negros fruit doves were shot in May 1953 at Mt Kanlaon. However, a local hunter in southern Negros claimed to have shot it in the nineties, which has given hope that the species may still exist, and as such the IUCN lists the Negros fruit dove as Critically Endangered, as any surviving population is likely to number fewer than 50 birds.[9][11] If the species still exists, it is likely that habitat destruction for agriculture, timber, and charcoal-burning and hunting, a common problem for all other pigeons on Negros, are major threats.[9]

As numerous collectors had visited Negros prior to 1953 and did not record the species, it is likely that it was already very rare by the time of its discovery.[8] It is suspected that the Negros fruit dove was originally a lowland species, but the destruction of forests in northern Negros forced the dove from its ideal habitat and led to its probable extinction.[8] Today, no forest exists in northern Negros at an elevation lower than 750 m (2,460 ft), and several searches in the 1990s of Mount Kanlaon and the surrounding area failed to discover any sign of the species' continued existence.[3][8] Ornithological fieldwork has discovered that the nearby island of Panay is home to some species previously thought to be endemic to Negros, including the Negros bleeding-heart.[8] This discovery and the presence of unexplored lowland forests on Panay give hope that the Negros fruit dove may still exist in low numbers on a nearby island.[8] Other than the depiction of the bird on a Philippine environmental education poster in the 1990s, no conservation measures have been enacted to protect any surviving population.[9]

• BirdLife Species Factsheet