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Mascarene Swiftlet Aerodramus francicus
BirdLife is updating this factsheet for the 2016 Red List
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This species is listed as Near Threatened because it is thought to have a moderately small population within a small range. The population on Réunion has increased substantially but that on Mauritius has declined, so the overall population trend is difficult to judge. Any evidence that the population is smaller than this or is declining overall may qualify the species for uplisting to a higher threat category.

Taxonomic source(s)
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

Taxonomic note
Aerodramus francicus (del Hoyo and Collar 2014) was previously placed in the genus Collocalia as C. francica.

Collocalia francica (Gmelin, 1789)

Distribution and population
Collocalia francica breeds colonially in caves and lava tunnels in Réunion (to France) and Mauritius (Cheke 1987c). In the 1970s, the species was much less common on Réunion than Mauritius (Cheke 1987b). More recently, discoveries on Réunion of several large colonies indicate that the population has since increased substantially to over 10,000 mature individuals (V. Bretagnolle in litt. 1999; M. Le Corre in litt. 1999 A. Cheke pers comm. 2000), including a small number of sites with more than 1,500 birds (Barré et al. 1996; A. Cheke pers comm. 2000; Le Corre and Safford 2001). On Mauritius, numbers have declined markedly in the last century, continuing through the last 20 years, with surveys in the 1990s indicating habitation of 34 caves, but complete removal of birds from a further 19. The population was estimated to be a minimum of 2,244-2,610 birds (G. Middleton per C. Jones in litt. 2000).

Population justification
The population on Réunion has been estimated at over 10,000 mature individuals (V. Bretagnolle in litt. 1999, M. le Corre in litt. 1999) and on Mauritius there is an estimated minimum of 2,244-2,610 birds (G. Middleton per C. Jones in litt. 2000), thus the total population is expected to fall within the range 10,000-19,999 individuals. This equates to 6,667-13,333 mature individuals, rounded here to 6,000-15,000 mature individuals.

Trend justification
Over recent years, the population on Réunion has increased substantially (A. Cheke verbally 2000), whilst that on Mauritius has declined, making it difficult to judge the overall population trend.

The species occurs over a wide range of habitats (del Hoyo et al. 1999). It feeds on winged insects (e.g. Diptera, flying ants and anthomyid flies) in flocks, usually 20 m above the ground, but lower over lakes and during cloudy weather. Nest building and breeding may take place virtually all-year-round. Nests are bracket-shaped and constructed using lichen filaments, held together with saliva. Two eggs are typically laid, rarely one, and the incubation period is probably 21-23 days, followed by a probable fledging period of 45-55 days (del Hoyo et al. 1999).

Collection for birds' nest soup and vandalism of caves are the principle threats on Mauritius (A. Cheke pers comm. 2000; C. Jones in litt. 2000). In an extreme case, the entrance of one cave has been completely filled in (C. Jones in litt. 2000). On Réunion, proposed development of canyoning and caving tourism may threaten some colonies, and protected areas may be needed (M. Le Corre in litt. 1999). Some colonies on Réunion are also threatened with disturbance during the study of caves by speleologists (del Hoyo et al. 1999). These threats are exacerbated by a shortage of suitable nest-sites (del Hoyo et al. 1999).

Conservation Actions Underway
No targeted conservation action is known for this species. Conservation Actions Proposed
Conduct surveys in order to obtain an up-to-date total population estimate. Monitor population trends through regular surveys. Protect nest-sites from exploitation, vandalism and disturbance. Develop a code of good practice with the tourist industry and speleologists.

Barré, N.; Barau, A.; Jouanin, C. 1996. Oiseaux de la Réunion. Les Éditions du Pacifique, Paris.

Cheke, A. S. 1987. An ecological history of the Mascarene Islands, with particular reference to extinctions and introductions of land vertebrates. In: Diamond, A.W. (ed.), Studies of Mascarene island birds, pp. 5-89. Cambridge University Press, Cambridge, U.K.

del Hoyo, J.; Elliott, A.; Sargatal, J. 1999. Handbook of the Birds of the World, vol. 5: Barn-owls to Hummingbirds. Lynx Edicions, Barcelona, Spain.

Le Corre, M.; Safford, R. J. 2001. La Réunion and Iles Eparses. In: Fishpool, L.D.C.; Evans, M.I. (ed.), Important Bird Areas of Africa and associated islands: Priority sites for conservation, pp. 693-702. Pisces Publications and BirdLife International (BirdLife Conservation Series No.11), Newbury and Cambridge, UK.

Further web sources of information
Explore HBW Alive for further information on this species

View photos and videos and hear sounds of this species from the Internet Bird Collection

Text account compilers
McClellan, R., O'Brien, A., Pilgrim, J., Robertson, P., Symes, A., Taylor, J., Warren, B.

Bretagnolle, V., Cheke, R., Jones, C., Le Corre, M.

IUCN Red List evaluators
Butchart, S., Taylor, J.

Recommended citation
BirdLife International (2016) Species factsheet: Aerodramus francicus. Downloaded from on 29/10/2016. Recommended citation for factsheets for more than one species: BirdLife International (2016) IUCN Red List for birds. Downloaded from on 29/10/2016.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.

Key facts
Current IUCN Red List category Near Threatened
Family Apodidae (Swifts)
Species name author (Gmelin, 1789)
Population size 6000-15000 mature individuals
Population trend Unknown
Distribution size (breeding/resident) 4,400 km2
Country endemic? No
Links to further information
- Additional Information on this species