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June 2004 Bird Numbers 13(1): 31 duced eight records, mainly from Marievale also caused them to be concentrated in areas Bird Sanctuary. The Free State province pro- with suitable habitat. duced six records, three from Seekoeivlei Wetland near Memel. The Eastern Cape pro- Acknowledgements duced five records, three from the Port Eliza- We would like to thank all who sent us their beth area. sightings and also those who made their In total, we are aware of 113 records of records known via SAbirdnet. We thank Corn Crake from the period 9 December Pieter van Zyl of the PCC/BiG Electronic 2003 to 15 April 2004, which represents Bird Monitoring Programme for extracting more records for South Africa than the total records for us. recorded during the atlas period (1987–92). It is difficult to identify specific reasons Taylor P.B. 1997. Corncrake Crex crex. In J.A. for this apparent irruption of Corn Crakes in Harrison, D.G. Allen, L.G. Underhill, M. South Africa. It is possible that short-term Herremans, A.J. Tree, V. Parker & C.J. Brown. population increases in the species’ breeding The atlas of southern African birds. Vol. 1: Non- range may have influenced abundance in our Passerines. p. 324. BirdLife South Africa, Jo- hannesburg. region, but other factors are believed to be Anderson N. in press. Corn Crakes Crex crex in primarily responsible. The summer of 2004 Wakkerstroom. had unusual weather, with very dry condi- BirdLife International. 2004. Information Sheet tions early in the season, particularly in on Corn Crake Crex crex. URL: http://www. northern parts, which could have ‘pushed’ birdlife.info/saps/sapDetails.asp?sid=2878 birds further south than usual, and perhaps 0 Seasonal movements and distribution of the Whitebellied Sunbird in western and central Namibia Wessel Swanepoel PO Box 21168, Windhoek, Namibia The Whitebellied Sunbird Cinnyris talatala Kaokoland, no Whitebellied Sunbirds were occurs in woodland and bush in the northern recorded from the area to the west of 16°E and eastern parts of southern Africa. Its pres- (ASAB2). The atlas records were from the ence is usually easily detected by its distinc- Broadleaved Tree-and-shrub Savanna biome tive vocalizations. Roberts’ (Maclean 1993) and marginally from Acacia Tree-and-shrub and most of the fieldguides indicate its range Savanna, in the less arid regions of Namibia covering northern Namibia, southward to the (Mendelsohn et al. 2002). Vegetation to the central parts, well to the south of Windhoek. south and west of the range, as indicated in There are old records from Okahandja in the atlas, consists of various types of arid central Namibia at latitude 22°S, as well as Acacia shrubland in the south, and arid from Sesfontein on the Hoanib River in the Acacia-Commiphora-Colophospermum dry northwest (Skead 1967). However, dur- shrubland in the west. These types of vegeta- ing the atlas period, Whitebellied Sunbirds tion seem to be unsuitable habitat for White- were recorded in Namibia from only the bellied Sunbirds when compared to that northern and northeastern parts, south to ap- within the atlas range. proximately 21°S. Except for northeastern Bird Numbers 13(1): 32 June 2004 New records in western and central River, Okahandja, 2216BB) Namibia Ugab River (Uis–Khorixas road, 2014DD) Aba-Huab River (near Twyfelfontein, Despite seemingly unsuitable habitat, the 2014CB) author recorded Whitebellied Sunbirds at Huab River (Khorixas–Palmwag road, various localities in western and central Na- 2014AC) mibia during the dry seasons of 2002 and Hoanib River (at its confluence with the 2003 (see distribution map). During the win- Obias River, 1913AD) ter of 2002, in July, several Whitebellied Sunbirds were unexpectedly recorded while At all these localities, ample time was spent feeding on blossoms of riparian ana trees endeavouring to locate Whitebellied Sun- Faidherbia albida, in the Okahandja River at birds by listening for their distinctive calls. Okahandja. This record is in central Namibia Except for the Kuiseb River, Whitebellied at 22°S and ±110 km south of its range ac- Sunbirds were recorded regularly at all the cording to the atlas. The birds were detected localities from July to October 2002 and by their ‘tzick’ call, usually uttered at take- June to October 2003. These periods coin- off and occasionally in flight. The highly cided with the flowering season of F. albida. distinctive ‘chewy’ call was less often heard. Good views of the birds were obtained, espe- Birds of both sexes, including juveniles, cially from road and rail bridges, which were present in approximately equal num- served as high vantage points at most of the bers, and occurred at a relative high density, localities. Apart from a few exceptions, all outnumbering sympatric Marico and Dusky records were of birds feeding on the blos- sunbirds by far. If I had not recognized their soms of F. albida. The exceptions were a few vocalizations, the birds would probably have cases where birds fed on flowers of a few remained undetected as they were mostly perennial plants: African Chestnut Stercualia silent and inconspicuous, feeding out of sight africana and the alien Wild Tobacco Nico- in the upper part of tall and densely foliated tiana glauca. Several specimens of the latter trees. were constantly visited by Whitebellied F. albida is almost unique in that it flow- Sunbirds and Dusky Sunbirds Cinnyris fus- ers in dry winter months when virtually no ca. At all the localities, Whitebellied Sun- other plant is in flower (Carr 1976). The fact birds occurred in sympatry with Dusky Sun- that Whitebellied Sunbirds were found feed- birds and, at the Okahandja and Ugab rivers, ing in it, prompted the author to search other with the Marico Sunbird Cinnyris mari- stands of F. albida. In Namibia, these trees quensis. occur in fairly high densities in riverine In central Namibia, Whitebellied Sun- woodland along the west-flowing ephemeral birds were also recorded unexpectedly at two rivers of the arid western and northwestern localities during the study period. In the city parts, outside the known range of the White- of Windhoek (2217CA), they were sparsely bellied Sunbird. Stands of F. albida at the recorded during July and August 2002, and following localities were visited regularly again in September 2003. They were ob- and searched for Whitebellied Sunbirds, served feeding on flowering garden plants from July 2002 to January 2004 (see also and on the exotic bottlebrush Callistemon sp. Fig. 1): Near Kalkrand, 180 km south-southeast of Windhoek, in Kalahari shrubland, they were Kuiseb River (Solitaire–Walvis Bay road, recorded during September 2002 and Sep- 2315BD) tember 2003, in a dense patch of mature Khan River (Usakos, 2215BA; Etiro, Camel Thorns Acacia erioloba. This patch of 2115DD) (visited only twice) A. erioloba is situated on the fossil banks of Okahandja River (a tributary of the Swakop the Skaap River, providing a possible migra- June 2004 Bird Numbers 13(1): 33 tion route from its source in the mountains south of Windhoek. Whitebellied Sunbirds occurred in sympatry with Marico and Dusky sunbirds and were seen feeding to- gether on flowers of the mistletoe Tapinanthus oleifolius, and in a near- by farm garden on exotic Callistemon sp. Discussion No Whitebellied Sunbirds could be found in western regions other than in the immediate vicinity of west- flowing ephemeral rivers with F. al- bida in the riverine vegetation. The birds were recorded only during the dry winter months, which coincided with the flowering season of F. albi- da. In south-central areas, records co- incided with the flowering season of A. erioloba and other Acacia species. However, in the veld, only flowers of the parasitic T. oleifolius growing on branches of A. erioloba were seen being visited. Searching other dense stands of A. erioloba near Rehoboth, which were devoid of mistletoe, pro- duced no Whitebellied Sunbirds. Figure 1. Distribution map of recent sightings of This was likewise the case north of Whitebellied Sunbirds. Omaruru, where in blooming Acacia woodland, only the mistletoe flowers were found during the study period at the Kuiseb utilised. Although the mistletoes at the Kalk- River locality, it is suspected to occur there rand locality were in flower throughout the during the dry season. Stands of mature F. study period, Whitebellied Sunbirds were albida are present in the riverine woodland only present while the A. erioloba were also of the Kuiseb River. This is likewise the case in flower. in the Gaub River to the south, a major tribu- The occurrence of Whitebellied Sunbirds tary of the Kuiseb, which marks the south- in western and central areas is clearly only ernmost point of distribution of F. albida in during the non-breeding season (ASAB2). Namibia. Although only a few selected lo- They are present June–October in western calities were searched, Whitebellied Sun- and north-central areas, with peak numbers birds are most likely to occur seasonally all in July and August. In the south-central area, along these rivers, including the Hoarusib in they are present only during September. In Kaokoland in the northwest. Juvenile White- western and north-central areas, their occur- bellied Sunbirds are also subject to seasonal rence is linked to the flowering season of F. movements as they were recorded at all lo- albida and in south-central areas to that of calities. Acacia species, particularly A. erioloba. All birds, of both sexes and age groups, Although no Whitebellied Sunbirds were were rather unobtrusive and mostly silent, Bird Numbers 13(1): 34 June 2004 except for occasional vocalizations as de- albida and mistletoe species, flower regu- scribed above. This is contrary to observa- larly in winter and throughout the year re- tions elsewhere in the range where the spe- spectively.

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