Introduction
The Bornean Swiftlet, Collocalia dodgei, is a small swiftlet in the family Apodidae. It is endemic to the mountains of northern Borneo and is most strongly associated with Mount Kinabalu in Sabah, Malaysia. The species was described in 1905 and was formerly treated by some authorities as a subspecies of the Cave Swiftlet or Glossy Swiftlet. Current bird taxonomies commonly recognise it as a distinct species, although its distribution and identification remain incompletely understood.
Physical Description
The Bornean Swiftlet is a small, compact swiftlet measuring approximately 10 centimetres in length. It has long, narrow wings, a short, nearly square tail and the streamlined body shape typical of aerial insectivores.
Adults are mainly dark grey to black above, with a subtle greenish gloss on the crown and upperparts. The underparts are pale to whitish, creating a useful contrast with the darker back. Compared with the similar Glossy Swiftlet, it is generally smaller and has a greener rather than bluish gloss. It also lacks the obvious white tail spots associated with some related swiftlets.
Sexual dimorphism has not been clearly documented, and reliable information on age-related plumage differences is limited. Identification is complicated by variation in light, viewing distance, moult and overlap with other white-bellied swiftlets. The feathering of the hind toes, sometimes used in museum-based identification, is not a practical field mark.
Range and Habitat
The Bornean Swiftlet is endemic to Borneo. Its best-established range is centred on the higher elevations of Mount Kinabalu in Sabah, Malaysia, where birds have been recorded around montane forest, cliffs and man-made shelters along the mountain access route.
Historical and recent records have suggested that it may occur on other Bornean mountains, including parts of Sabah, but some records are difficult to separate from the similar Plume-toed Swiftlet. The species should therefore not be assumed to occur throughout Sabah, Sarawak, Brunei or Kalimantan solely because these regions lie within Borneo.
It is principally associated with upper montane environments. Reported records span roughly 1,500 to 2,700 metres on Mount Kinabalu, although the precise lower and upper limits of its range remain uncertain. Unlike the original article’s description, the species is not best characterised as a lowland rainforest or general limestone-cave swiftlet.
Where to See This Species
Kinabalu Park, Sabah, Malaysia
Kinabalu Park is the most reliable publicly accessible venue for looking for the Bornean Swiftlet because the species is documented from the Mount Kinabalu massif. The best opportunities are at higher elevations along the road and mountain route, particularly around Timpohon Gate and nearby cliffs or shelters where swiftlets have been observed nesting or roosting. Identification should be made cautiously, preferably from birds associated with known nesting sites rather than from distant birds seen only in flight.
Nearby accommodation: Practical accommodation is available around Kinabalu Park headquarters and in the gateway settlements of Kundasang and Ranau, including park lodges, guest houses, hotels and other small tourism establishments.
Behaviour and Diet
The Bornean Swiftlet spends much of its time in flight and captures small airborne insects while hawking over forested slopes, mountain roads and open areas. Its diet is expected to include flying insects such as small flies, beetles and other soft-bodied invertebrates, although detailed species-specific dietary studies are limited.
Swiftlets are generally social and may gather in groups while foraging, roosting or nesting. The Bornean Swiftlet has been recorded using cliffs, crevices and artificial structures associated with the Mount Kinabalu route. Available observations indicate that nests may be built on sheltered ledges or structures using plant material bound with saliva. It should not be confused with edible-nest swiftlets, whose largely saliva-based nests are collected for bird’s-nest soup.
Detailed information about courtship, clutch size, incubation and fledging is scarce. The species’ breeding biology requires further study, particularly because nesting sites can be difficult to access and identification may be uncertain.
Identification Tips
Look for a small, pale-bellied swiftlet in high-elevation habitats around Mount Kinabalu. The most useful field impressions are:
- dark grey to black upperparts with a subtle greenish gloss;
- pale or whitish underparts;
- a small body and relatively short, square-looking tail;
- association with high montane slopes, cliffs or shelters rather than lowland swiftlet habitat; and
- nesting or roosting at confirmed high-elevation sites, especially around Timpohon Gate.
The main identification difficulty is separation from the Plume-toed Swiftlet and other white-bellied swiftlets. Plumage gloss is variable and should not be used alone. Birds seen only in flight, particularly away from confirmed nesting sites, are best treated cautiously unless photographs, calls, location and other features support the identification.
Conservation Status
A separate current IUCN Red List category for Collocalia dodgei could not be verified. Earlier conservation assessments treated the taxon within the broader Cave Swiftlet complex, so those assessments should not automatically be applied to the currently recognised Bornean Swiftlet.
There is no reliable published population estimate for the species, and its population trend is uncertain. The principal conservation priorities are protection of high-elevation forest on Mount Kinabalu, safeguarding known nesting and roosting sites, careful management of visitor access and improved monitoring of swiftlets at other Bornean mountain ranges. Further genetic, acoustic and field research is also needed to clarify the species’ true distribution and distinguish it from closely related swiftlets.
Frequently Asked Questions
Where is the Bornean Swiftlet found?
It is endemic to Borneo and is best documented from high elevations on Mount Kinabalu in Sabah, Malaysia. Records from other Bornean mountains require careful confirmation because similar swiftlet species occur in the region.
Is the Bornean Swiftlet a separate species?
Most current bird taxonomies recognise Collocalia dodgei as a distinct species. It was formerly treated by some authorities as a subspecies of the Cave Swiftlet or Glossy Swiftlet, and taxonomic discussion continues because the white-bellied swiftlet group is difficult to identify.
What does the Bornean Swiftlet eat?
It feeds on small flying insects captured during aerial foraging. Its diet probably includes flies, beetles and other airborne invertebrates, although detailed studies of this species are limited.
Does the Bornean Swiftlet make edible bird’s nests?
There is no good basis for describing it as an edible-nest swiftlet. Its nests are associated with sheltered ledges, crevices and structures, and may contain plant material bound with saliva. The nests harvested for bird’s-nest soup are produced mainly by other swiftlets, especially species in the genus Aerodramus.
Where is the best place to see the Bornean Swiftlet?
Kinabalu Park, particularly the higher Mount Kinabalu route around Timpohon Gate, is the most reliable publicly accessible location. Birds should be identified cautiously because Plume-toed Swiftlets and other similar species may also occur in the wider area.
References
- AviList
- Moyle et al., Bulletin of the British Ornithologists’ Club
- Sabah Parks
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