CWAC: Coordinated Waterbird Counts

Fish Eagle

INTRODUCTION
Birds are indicators of wetland health. Regular counts are undertaken by the EKZNW staff to detect changes in waterbird populations and wetland conditions.

All the data are sent to the newly named Animal Demography Unit (ADU) at the University of Cape Town (UCT) for inclusion into Wetland International’s African Waterbird Census (AfWC) Programme.

Of the 32 sites in the Coastal Maputaland region 2 were not counted due to logistical problems. Six of the pans were completely dry and no birds were recorded there. A further 2 pans were in the process of drying out.

The long running drought is persisting in the region with the occasional wet spell bringing some relief to Nsumo, Muzi and Yengweni pans. The lake level in Lake St Lucia has been steadily declining since the mouth breached in March 2007 and its subsequent closure in late August. The salinity has been steadily rising and an average salinity of 45 ppt was measured in the main lake. The dry-down conditions are making some pans more suitable for some birds and there have been some local movement of birds to these.

METHODS
Counting at Kosi Lakes and Lake Sibaya is carried out by boat and the count at Lake St Lucia is covered by air. For these most of the water surfaces are covered. The rest of the counts are conducted by vehicle and foot from specified vantage points around the water. Not all the water surfaces or shorelines are completely counted for these. All waterbirds are counted – congregations of larger numbers of birds are estimated, photographed and then counted later off the digital photograph.

RESULTS
A total of 18000 birds were counted in this survey – the waders made up the largest portion at 30% (most were observed in Lake St Lucia). Then came the pelicans (26%) with 500 Pink-backed Pelicans breeding at Nsumo Pan and the rest being observed by air at Lake St Lucia. The gulls and terns were the next largest portion observed (18%) with most of these being seen at Lake St Lucia.

Of interest was a Half-collared Kingfisher seen at Muzi Pan – this bird prefers well vegetated shorelines as well as coastal lagoons, rivers and estuaries. It is shy and inconspicuous and perches low over the water on a rock or branch. Its diet consists mainly of small fish. There has been a recent decrease in population of this species as a consequence of pollution, siltation and habitat loss in KZN.

Also of interest were 2 Black Herons (egrets) seen at Yengweni Pan. These birds are associated with shallow perennial waters and seasonally flooded grasslands. They have a unique fishing method called the “umbrella method” whereby they form a canopy with their extended wings over their heads in order to catch prey (there is much debate as to the exact reasons for this).

Breeding was recorded for the following species: Pink-backed pelicans and yellow-billed storks at Nsumo Pan, saddle-billed stork in the Wilderness of Eastern Shores and white-faced ducks at Yengweni Pan, Sodwana sewage works and Mavuya Pan. The White-breasted Cormorants are congregating at their usual site at Lake Sibaya prior to breeding.

Thanks to all the participants: M. Bowker, C. Fox, J. Gumbi, R. Kyle including the family, S. Masondo, A. Myeza, G. Nanni, O. Nyawo, B. Nxele, W. O’Dell, H. Sibisi, R. Taylor, W. Taylor and D. Tembe. Your help was greatly appreciated.