Key sites for the conservation of waterbirds (Aves) in Durban Bay, South Africa

• Main Authors: McInnes, AM, Allan, DG, Malan, G
• Format: Others
• Language: en
• Published: Durban Museum Novitates 2005
• Subjects: Abundance; Conservation
• Online Access: http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001003

Key sites for the conservation of waterbirds (Aves) in Durban Bay, South Africa. Durban Museum Novitates 30: 1-14. Forty-eight monthly counts of waterbirds were conducted in Durban Bay (July 1999-June 2003). A total of 47 227 waterbirds of 79 species were recorded. Eighteen waterbird species were significantly more abundant in summer while seven were significantly more abundant in winter. Centre Bank supported 40.6% of all waterbirds, comprising mainly Palearctic waders and roosting gulls and terns. Distinct species assemblages of plovers (Charadridae) and sandpipers (Scolopacidae) were associated with the two most selected of the intertidal sites: Bayhead and Centre Bank. The assemblage at Centre Bank included three large-bodied Palearctic species (Greenshank, Grey Plover and Whimbrel), all of which occurred in abundance there and showed strong selection for this site. The assemblage which showed strong site selection for Bayhead consisted of both resident and Palearctic species, five of which are known to favour finer sediments (Ringed and Kittlitz's plovers, Common and Terek sandpipers, and Little Stint). Bayhead had a higher number of waterbird species that occurred at higher densities, when compared with Centre Bank, and showed the highest species-diversity ranking of all sites. This may be a result of the more heterogenous nature of this area. Sporting Bodies- Pelican Island had high densities of, and strong site selection by, piscivorous species and species associated with the semi-natural shorelines of this area. This site, however, supported only 8.6% of all waterbirds counted during the study period. Fish Wharf-Yacht Basin had the highest numbers and densities of Greyheaded Gulls, which utilized this area when scavenging. Other waterbird species were poorly represented here and this site had the lowest species-diversity ranking. Commercial harbour areas were the least attractive for waterbirds in terms of species-abundance values, densities and site selection. This is largely attributed to the artificial nature of these areas. It is recommended that Centre Bank receive highest priority for conservation status within the Bay. Reasons for conserving this site include: (a) the high overall abundance of waterbirds that this site supports; (b) the unique assemblage of Palearctic waders that utilizes this area, and the overall contribution that this has to waterbird diversity in the Bay; and (c) the importance of this site to roosting gulls and terns, particularly Kelp Gull which has regionally, and potentially globally, significant numbers in this area.