Title:

The breeding and population status of the African Skimmer Rynchops flavirostris in Botswana

Author(s):
Publication Year:
2004
Abstract:

The African Skimmer Rynchops flavirostris was identified as a national Red Data species in Botswana because of its small, vulnerable and possibly declining breeding populations (Tyler and Borello 2000). BirdLife International (2004) listed the species as near-threatened in a global context, estimating the total population in Africa to be 10 000–20 000 birds. Following some surveys of African Skimmers on the Okavango River in 1994 (Vial 1995), the status and distribution of the species in Botswana were described by Tyler and Stone (2000). The African Skimmer is an intra-African migrant and disperses widely after the breeding season. Its African range includes major rivers and lakes south of the Sahara, Senegal east to Sudan and south-western Ethiopia south to extreme northern Namibia (Cunene River), northern Botswana, the basin of the Zambezi River and southern Mozambique (Urban et al. 1986, Zusi 1996). In South Africa the African Skimmer no longer breeds in KwaZulu Natal nor anywhere else (Tree 1989, Zusi 1996, Harrison et al. 1997). It occurs as a non-breeding visitor north-west to the Gambia River and on stretches of the Nile River in Egypt where it may have bred on Lake Nasser in 1987 (Zusi 1996). The largest breeding colonies rarely support more than 50 pairs but 1 550km of the middle and upper reaches of the Zambezi during 1986 and 1987 supported an estimated 1 428 birds (Coppinger et al. 1988). The largest nonbreeding flocks may be 1 000–1 500 strong as recorded in Kenya and Tanzania (Britton 1980). In Botswana breeding by African Skimmers is confined to the Chobe River near Kasane (17°48'S, 25°09'E) and the Okavango Delta (19°15’S, 22°45’E) (Figure 1). Colonies are active mainly from August through to November when water levels are low and sandbanks exposed (Skinner 1997, Tyler and Stone 2000). Away from the northern wetlands, there are records from the Boteti River (linking the Okavango Delta with Ntwetwe Pan in the Makgadikgadi Pans), in the Makgadikgadi Pans from Lake Xau (Dow) (21°18'S, 24°45'E), Mopipi dam (21°12'S, 24°52'E) and from Lake Ngami (20°25'S, 22°50'E). Penry (1994) reported that pairs had bred in the past at Mopipi and at Lake Ngami. However, there appears to be no evidence for breeding ever having occurred either at Lake Xau, Mopipi Dam, on the Boteti River or at Lake Ngami (WD Borello in litt.). There was a vagrant at Ngotwane sewage ponds in Gaborone (24°39'S, 25°54'E) in late June 1998 (Tyler 1998, 2001). Casual records of skimmers in Botswana from 2000 to 2004 have been published in issues of Babbler, the journal of BirdLife Botswana. This note summarises these records, thereby updating Tyler and Stone (2000).

Publication Title:

Ostrich

Volume:
75
Issue:
4
Pages:
329-332
Item Type:
Journal Article
Language:
en