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.
Contact the BirdLife Red List Team under redlistteam [at] birdlife [dot] org.