WHITE-BREASTED CORMORANTS Phalacrocorax carbo lucidus MORE ABUNDANT IN SOUTHERN AFRICA THAN PREVIOUSLY THOUGHT

John G.M. Wilson & Koos Van Zegeren

Several waterbird counts carried out along the Upper Shire River in the Liwonde National Park, Malawi, by Robert Nyirenda, Bob Medland and the authors have revealed consistently high numbers of White-breasted Cormorants Phalacrocorax carbo lucidus (Table 1). These figures do not include estimates of other White-breasted Cormorant populations in Lake Malawi, totalling about 10,000 birds (5,150 at Boadzulu Island, 2500 at Mumbo Island and 1,850 at Nakatenga Island, Senga Bay, a colony of about 400 on Chisumulu Island and a small colony located at Nsanje on the Lower Shire River; Linn & Campbell 1992). Together with the Upper Shire River population at Liwonde National Park of about 5,000 individuals, the total number of White-breasted Cormorants in Malawi would consist of about 15,000 individuals, rather more than the 6,000 birds estimated by Rose & Scott (1994) for the whole of southern Africa. This estimate has recently been raised to 10,000-25,000 birds, which still means that Malawi alone holds at least an 60% of the total population in this region.

Further north, the species may also be more abundant than Rose & Scott's (1994) estimate of 15,000 birds for western and eastern Africa would suggest. A preliminary survey of waterbirds at lake Ziway, Ethiopia, produced about 4,000 birds (Fekadu Teferra in litt.), which together with other recent material from western and eastern Africa justifies the recent upgrading of this region's estimate to 100,000-1,000,000 birds (Paul Rose in litt.).

References

Linn I.J. & Campbell K.L.I. 1992. Interactions between White-breasted Cormorants Phalacrocorax carbo (Aves: Phalacrocoracidae) and the fisheries of Lake Malawi. Journal of Applied Ecology 29: 619-634.

Rose P.M. & Scott D.A. 1994. Waterfowl Population Estimates. IWRB Publication 29. International Waterfowl and Wetlands Research Bureau, Slimbridge.

John G.M. Wilson, Wildlife Society of Malawi, P.O. Box 537, Zomba, Malawi