African Skimmer Rynchops flavirostris Scientific name definitions

36–42 cm; 111–204 g; wingspan c. 106 cm; culmen of male 61–70 mm, of female 51–62 mm. Unmistakable within range. Smaller than congeners; differs from niger by pale whitish-yellow tip to bill ; from albicollis by black hindneck in breeding plumage. Non-breeding adult has white nuchal collar and somewhat browner upperparts . Female similar to male. Immature similar to non-breeding adult, but generally browner above, with buff fringing and mottling, and paler bill.

Major rivers and lakes of Africa S of Sahara, from Senegal E to Sudan and SW Ethiopia and S to extreme N Namibia (R Cunene), N Botswana, basin of R Zambezi and S Mozambique; may have bred in S Egypt (on L Nasser) in 1987. Non-breeding visitor NW to R Gambia and Egyptian stretches of R Nile.

Rivers at low water, coastal lagoons, saltpans, open marshes, lakes; less common along coast. Rests and breeds on sandbars and beaches. Recorded to 1800 m (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ), in some regions only wandering to highest altitudes outside breeding season (2 Dowsett, R. J., D. R. Aspinwall, and F. Dowsett-Lemaire (2008). The Birds of Zambia. Tauraco Press & Aves, Liège, Belgium. Close ).

Migrates up and down larger rivers, and to and from inland lakes, over distances of up to at least 600 km (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ), with vagrants or wandering birds occasionally appearing outside normal range, e.g. at Gabarone, Botswana, in Jun (3 Tyler, S.J. (2004). The breeding and population status of the African Skimmer Rynchops flavirostris in Botswana. Ostrich. 75(4): 329-332. Close ), coastal SE Somalia in Jun–Aug and Jan (4 Ash, J. S., and J. E. Miskell (1998). Birds of Somalia. Pica Press, Robertsbridge, UK. Close ), Eritrea in Dec–Mar (5 Ash, J. S., and J. Atkins (2009). Birds of Ethiopia and Eritrea: An Atlas of Distribution. Christopher Helm, London, UK. Close ), and non-breeders regularly reaching as far N along Nile R as Egypt, usually only as far as L Nasser, but occasionally further N (6 Sueur, F. and Siblet, J.-P. (2010). Observations ornithologiques en Égypte (juillet-août 272728 et mars 272729). Alauda. 78(1): 69–73. Close ). Present in Zimbabwe only during Apr–Dec (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ). Uncommon on coast, but outside breeding season may congregate in estuaries, e.g. well over 200 birds together off Bonthe, Sierra Leone, in Jan, and c. 300 at mouth of Cross River, SE Nigeria, in Feb (7 Künzel, T. and Künzel, S. (1999). First Nigerian record of Red-fronted Parrot Poicephalus gulielmi, and other notable records from SE Nigeria. Malimbus. 21(1):111–113. Close ). One was found on Bioko island, Equatorial Guinea, in October 2014 (8 Cooper, J. C., L. L. Powell, and J. D. Wolfe (2016). Notes on the birds of Equatorial Guinea, including nine first country records. Bulletin of the African Bird Club 23(2):152–163. Close ). Inland, concentrations of up to 600 birds recorded at Lochinvar, Zambia, during local dry season (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ). One historical record (Jan 1839) from unknown distance offshore in Atlantic Ocean S of equator following in a storm (9 Craig, A.F.J.K. and Hummel, H.C. (1993). J. A. Wahlberg's records of birds and other animals in the Atlantic Ocean in 1838-1845. Marine Orn.. 21(1–2): 71–73. Close ). Recent record from S Oman (the only one from outside Africa), involving two birds, in Jan–Feb and May 2015 (10 van den Berg, A.B. (2015). WP reports. Dutch Birding. 37(2): 122–129. Close , 11 Harrison, I. (2015). From the rarities committees. Sandgrouse 37(2):203–210. Close ).

Fish, e.g. cichlids, up to 8 cm long (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ). Crepuscular and nocturnal, as well as diurnal. Food caught exclusively by skimming the water in flight with mouth open and lower mandible submerged, the bird skimming for 50–100 m in one direction, then often returning along same path in opposite direction (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ); prey items touched by mandible are grasped while head doubles back under body; prey swallowed in flight or after landing.

Generally vocalizes rather infrequently, most usually in flight and principally around colonies: a soft shrill cooing is heard during courtship, but more commonly heard are a sharp loud “kip-kip-kip” and a more drawn-out, harsher and tern-like “kreeep” (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ).

Laying generally Mar–Jun in W & E Africa, mainly Jul–Nov S of equator (e.g. Aug–Nov in Botswana) (3 Tyler, S.J. (2004). The breeding and population status of the African Skimmer Rynchops flavirostris in Botswana. Ostrich. 75(4): 329-332. Close ); season varies locally depending on local dry season and period of low water in river. Colonial, often with terns, plovers, pratincoles and other species; birds chase one another noisily day and night on arrival at colony, usually 1–2 weeks prior to start of breeding (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ). Nests on sandy beaches and sandbars in rivers and islands in lakes; nest is unlined scrape (220–280 mm × 40–45 mm) (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ) in sand; usually sited within 28 m of waterline and 2–14 m apart (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ). Clutch usually 1–3 (mean 2·6), but more rarely 4–5 (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ) (e.g. in Zambia, 16 clutches of one egg, 37 of two eggs, 73 of three, 19 of four and just one of five) (2 Dowsett, R. J., D. R. Aspinwall, and F. Dowsett-Lemaire (2008). The Birds of Zambia. Tauraco Press & Aves, Liège, Belgium. Close ), usually laid at night over period of several days; buff heavily blotched brown or purplish brown (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ); 35·7–43·1 mm × 26·4–30 mm, 15·1–17·5 g (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ); incubation c. 21 days, by both sexes, but mainly by female, with rate of changeover increasing with rise in temperature during day (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ); chick (9·7 g on hatching) (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ) has buffy white down, with irregular peppering of small black dots mainly on crown and rump (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ); tended and fed fish by both parents; stays in nest scrape for two days; fledging c. 4 weeks. Occasionally double-brooded (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ). Few data on breeding success, but study of four colonies and eight single nests on 40 km of river in Botswana found that of 171 eggs in 67 clutches, only 47 eggs hatched and just 11 young fledged (0·14 young fledged per nest) (3 Tyler, S.J. (2004). The breeding and population status of the African Skimmer Rynchops flavirostris in Botswana. Ostrich. 75(4): 329-332. Close ). Rising river water may destroy colony; eggs may be trampled by hippopotami and elephants; predators include raptors, e.g. African Fish-eagle (Haliaaetus vocifer), Black Kite (Milvus migrans) and African Marsh-harrier (Circus ranivorus) (3 Tyler, S.J. (2004). The breeding and population status of the African Skimmer Rynchops flavirostris in Botswana. Ostrich. 75(4): 329-332. Close ), and other birds, e.g. gulls (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ), Yellow-billed Stork (Mycteria ibis), Sacred Ibis (Threskiornis aethiopicus), Hamerkop (Scopus umbretta) and Coppery-tailed Coucal (Centropus cupreicaudus) (3 Tyler, S.J. (2004). The breeding and population status of the African Skimmer Rynchops flavirostris in Botswana. Ostrich. 75(4): 329-332. Close ), mammals, lizards and snakes (cobras) (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ), e.g. Nile crocodile (Crocodylus niloticus) and water monitor lizard (Varanus niloticus) (3 Tyler, S.J. (2004). The breeding and population status of the African Skimmer Rynchops flavirostris in Botswana. Ostrich. 75(4): 329-332. Close ); parents will mob some species even away from nest, others only when near nest.

Not globally threatened. Currently considered to be Near Threatened and probably in decline. Recently listed on Appendix 2 of the Convention on the Conservation of Migratory Species of Wild Animals (12 Demey, R., Lack, P. and Webb, R. (2007). Africa Round-up: Protection for African migrants. Bull. African Bird Club. 14(1): 10. Close ). Total population estimated at 10,000–17,000 mature individuals, or 15,000–25,000 birds overall, of which 7000–13,000 in Western & Central Africa and 8000–12,000 in East & Southern Africa; largest colonies support only c. 50 pairs. Census of 1550 km of upper and middle R Zambezi in 1986–1987 yielded 1428 birds (3 Tyler, S.J. (2004). The breeding and population status of the African Skimmer Rynchops flavirostris in Botswana. Ostrich. 75(4): 329-332. Close ); largest recorded flocks of non-breeders include 1000 birds in Kenya and 1500 in Tanzania.

Southern African populations are decreasing. The species is rare and no longer breeds in South Africa. In Natal, where it last bred in 1943, it ceased to be recorded in 1970s (1 Urban, E. K., C. H. Fry, and S. Keith, Editors (1986). The Birds of Africa. Volume 2. Academic Press, London, UK. Close ). However, records in northern South Africa have been more frequent in recent years and a pair attempted to nest twice, unsuccessfully, at the Albasini dam, Limpopo province, in September and October 2016 (13 Englebrecht, E. and Mulaudzi, S. (2017). New breeding species. African Skimmer. African BirdLife. 5(3): 14. Close ).  In Botswana , largely restricted as a breeder to Chobe R and Okavango Delta, at least in present-day, with breeding population estimated at no more than 200–300 pairs (3 Tyler, S.J. (2004). The breeding and population status of the African Skimmer Rynchops flavirostris in Botswana. Ostrich. 75(4): 329-332. Close ). Dams flood habitats upstream and alter flow downstream producing unsuitable breeding conditions; DDT spraying for malaria and against tsetse fly and agricultural pests is dangerous for fish-eaters. Egg-collecting routinely practised, e.g. in Botswana (3 Tyler, S.J. (2004). The breeding and population status of the African Skimmer Rynchops flavirostris in Botswana. Ostrich. 75(4): 329-332. Close ), and this is facilitated by fact that incubating adults tend to be conspicuous; in addition, disturbance of colony by humans and cattle during hottest season is often fatal to eggs and chicks, while even incidental factors such as inundation of nests by waves caused by boat traffic, or trampling of nests and eggs by cattle, can be locally important reasons for breeding failure (3 Tyler, S.J. (2004). The breeding and population status of the African Skimmer Rynchops flavirostris in Botswana. Ostrich. 75(4): 329-332. Close ). Pollution, overfishing and decimation of native fish faunas by introduced predatory fish is a potential problem in many lakes.