Archived 2012-2013 topics: Dark-rumped Swift (Apus acuticauda): uplist to Endangered?

BirdLife species factsheet for Dark-rumped Swift Dark-rumped Swift Apus acuticauda is known from just a few breeding colonies in the Himalayan foothills in Bhutan, and the hills of Meghalaya, Nagaland and Mizoram, north-east India (BirdLife International 2001, Chantler 2005, Ahmed et al. 2007). There are records throughout the year from India and during the non-breeding season from north-west Thailand and Yunnan, China (J. Hornskov in litt. 2005). It is currently listed as Vulnerable under criterion D1 because it was thought to have a very small population of <1,000 mature individuals. However, recently revised population estimates suggest that the global population of this species numbers 250-999 individuals, based on estimates of breeding colony sizes ranging from a few to 200 individuals. This estimate equates to 167-666 mature individuals, rounded to 150-700 mature individuals. Also, M. F. Ahmed in litt. 2012 advises that if estimates are based on known populations, the total population of this species is unlikely to be higher than 500 individuals. If there is sufficient evidence to suggest that the global population of the Dark-rumped Swift may number <250 mature individuals, it would warrant uplisting to Endangered under criterion D1 of the IUCN Red List. Little is known about this species; in particular, its seasonal movements and wintering areas remain poorly understood.  Information is requested on its potential population size, distribution, trends and threats, and any further comments on the proposed uplisting are welcome. References: Ahmed, M. F., Das, A.; and Meyase, V. (2007) Khasi Hills Swift Apus acuticauda: First record from Nagaland and Manipur, north-east India. Journal of the Bombay Natural History Society 104(1): 87-88. BirdLife International (2001). Threatened birds of Asia: the BirdLife International Red Data Book. BirdLife International: Cambridge, U.K. Chantler, P. (2005) Dark-rumped Swifts: notes on their breeding plumage and how to see them. BirdingASIA: 39-40.

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6 Responses to Archived 2012-2013 topics: Dark-rumped Swift (Apus acuticauda): uplist to Endangered?

  1. I have heard of recent claims from far-N Myanmar (contact Robert J. Tizard) and Cambodia (contact Fred Goes) – I am not sure who were the original observers but these will know. Such records might be relevent to assessing the Red List c&c for the species

  2. Lynda Donaldson says:

    David Bishop provided the following information on 1 July 2013:

    Dark-rumped Swift Apus acuticauda

    David Bishop’s field notes:

    1995: 10 birds seen over forest during low cloud conditions strongly resembled this species. Final confirmation awaits examination of specimens; c. 7000 ft Lower Limithang Road.

    1 May 1996: Common Swift
    Apus apus – Approximately 200 migrating with other swifts at c. 1000m just east of Deothang. This is the first record of this species for Bhutan. I’m now wondering if these were in fact Dark-rumped Swifts????

    16 – 18 April 1998: At least four seen very well, together with other swifts, over lightly wooded farmland, above Deothang. A total of ten observed on two afternoons, together with other swifts, along a steep sided canyon, above Somdrup Jonkhar.

    14 – 15 May 1999: A maxima of 8-14 observed on two afternoons, together with other swifts, along a steep sided canyon, above Somdrup Jonkhar.

    May 2000: No records. A huge amount of disturbance to the road from Deothang and above to Morong, apparently designed to reduce the opportunity of ALPHA elements being active in this area. Disturbance below Deothang to Somdrup Jonkhar whilst not as pronounced nevertheless was present and may have bee responsible for the lack of records of this species this year.

    3 May 2001: As many as ten, probably more, seen superbly as they flew in during the late afternoon and entered their nest site, c 350 m, near Somdrup Jonkhar. Upon entering the nest site the entire upperparts were exposed to scrutiny permitting clear view of the entirely uniform dark colouration. In flight the scaly underparts and forked tail were clearly visible.

    2002: No records because I did not visit the SE of Bhutan that year.

    2003, 2004, 2005: Exit via Somdrup Jonkhar no longer permitted so we and all other bird-tours departed Bhutan via Paro.

    20-21 April 2006: A flock of ten just above Deothang put on a great show. Exit to India via Somdrup Jonkar reopened this year.

    3 April: Five above Tingtibi both at our camp and in the hydro area gave repeat excellent views showing the key features of this rare and highly localised species. A surprise in this location where I have camped three times previously and despite scouring all Fork-tailed Swifts had never encountered this species before. This was lucky because at the best site for this species we were fogged in. Notes from my colleague Dion Hobroft who led a second VENT tour this year.

    Tingtibi Camp site 740 metres elevation 27° 10.37’ N, 90° 41.90’ E, located in a narrowish valley with moderately steep, forested sides.

    5-6 May 2007: a flock of ten below Deothang on two days put on a great show.

    6 April: Four at Tingtibi at our camp in the hydro area gave an excellent flight view showing the key features of this rare and highly localised species. Also excellent views of 4-5 birds on both 16-17 April near Somdrup Jonkar. Notes from my colleague Dion Hobroft who led a second VENT tour this year.

    7 May 2008: a flock of ten below Deothang put on a great show.

    29 April 2009: Sadly the road widening below Deothang is so horrendous that much of what was good roadside birding habitat has been destroyed. Nevertheless we still managed to dig out a few goodies including fine views of Asian Fairy Bluebirds. Unfortunately no records of Dark-rumped Swift this year almost certainly a reflection of the roadside disturbance in the close vicinity of this species previous nest site.

    23 April 2011: Three possibles over the Limithang Road ca 1800m elevation.

    19-20 April 2013: One seen by Rolph on the Tama La Rd. and then another seen well with other swifts below Jigmecholing.

    Summary: The only experiences that have of Dark-rumped Swift are from Bhutan where I have observed it as detailed above. This species is very difficult to identify with certainty and requires a great deal of care as I have learnt on numerous occasions when observing flocks of Pacific Swift (sic) together with smaller numbers of Dark-rumped Swift. I can confirm that I have observed this species entering narrow slots in the wall of a narrow steep sided canyon at circa 360m elevation above a forest-lined small river ca 5 km above the township of Somdrup Jonkar, located in south-east Bhutan close to the border with Assam, India. Birds attending what I presume to be their nest site are best seen at dusk when they appear seemingly our of nowhere and descend from high before dashing into their slot. I have also observed this species above circa 1000m above the town of Deothang, also in SE Bhutan foraging over open grassy cattle pasture together with other swifts, especially Pacific Swift. My colleague Dion Hobcroft has twice observed this species at ca 750 m elevation above the town of Tingtibi in habitat described above. I understand others have also recorded this species at this site and I may have observed this species there on one occasion but my observation was not absolutely conclusive. During the 2013 trip there were two records detailed above but to my mind they were not conclusive and as they would represent a new locality should probably await confirmation.

    I suspect this species is overlooked and may well occur at a number of as yet undiscovered sites along the southern reaches of Bhutan wherever suitable nesting cliffs exist. However, the recent huge increase in disturbance to Bhutan in the form of road-widening to facilitate the building of large hydro-electric schemes should be regarded with considerable concern for species such as this. Given all of the above I recommend that this species’ global status be ‘elevated’ to Endangered.

  3. Simon Mahood says:

    Are threat assessments usually based on the number of individuals in known populations…?

    Although few breeding colonies are known, Meghalaya, Mizoram and Nagaland are some of the least-watched parts of India, this combined with the difficulty in identifying the species makes it likely that there are unknown populations out there. Also, given the relatively low observer density in Yunnan and northern Thailand would you expect a species with a population of <250 mature individuals to have been recorded during its non-breeding wanderings? The population must surely be higher than the total of known individuals.

    I do not support uplisting in this case.

  4. Craig Robson says:

    I must be missing something here. Is there any evidence that this species has ever declined, or is under any threat? There are clearly more than 250 easily visible around Cherrapunji. It is common and easily seen around its breeding cliffs in that region – which are completely inaccessible.

  5. Manoj Sharma says:

    A flock of 30-40 was present at Khonoma Wildlife Sanctuary, Nagaland in May 2011.

  6. James Eaton says:

    I agree with Craig and Simon, given large areas of its range remain unsurveyed but very possibly still ideal areas for them to occur I can’t see a reason to upgrade the species, especially as records at its known sites have remained stable for many years, ie at Cherrapunji.

    In late April 2013 I recorded 6-10 just north of Sumdrup Jongkar in SE Bhutan also – another very little studied area.

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