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The regional population of Black Stork Ciconia nigra is estimated at less than 1 000 mature individuals satisfying the population size criterion for regionally Vulnerable. In addition, a population size reduction of greater than 30% is suspected to have occurred over a 47 year period (three generations).
The Black Stork breeds widely across the Palearctic region and is a partial migrant into sub-Saharan Africa, remaining largely north of the equator (Snow and Perrins 1998, Hancock et al. 2010). The Sahelo-Sudanian part of Africa (the south of Mauritania, Burkina Faso, Niger and the north of Benin) constitutes the principal known wintering destination of Black Storks from Western Europe between September and March (Chevallier et al. 2011, Jiguet et al. 2011). The population occurring in southern Angola, Zambia, Malawi, Tanzania and Mozambique is isolated from that in the northern hemisphere (Siegfried 1967). Within the region, it occurs predominantly in the southern and eastern provinces, avoiding the drier interior and west (Siegfried 1967). The species is suspected to undergo complex seasonal movements (Tarboton et al. 1987). The EoO provided by SABAP2 is large (1 481 285 km2) and has decreased only slightly (4.26%). In contrast, the AoO has decreased dramatically from 531 886 km2 to 193 128 km2, a decline of 63.7%. The species is well represented in the protected areas network, occurring in over 40 IBAs.
The global population is estimated at 24 000-44 000 mature individuals (Dodman and Diagana 2006). There are no reliable up to date estimates for the region. Clancey (1985) provided an initial southern African population estimate of c. 400 mature individuals which was updated by Dodman and Diagana (2006) to 1 560-4 050 mature individuals. Osborne and Tigar (1990) estimated there to be up to 50 pairs in Lesotho while Parker (1994) estimated 10 pairs in Swaziland. While these figures are out of date, it is estimated that the regional population is less than1 000 mature individuals. Confidence in this estimate is low and a revision of the regional population size is urgently required.
The population trend of the global population is unknown (BirdLife International 2014). The AoO occupied by this species has decreased dramatically between reporting periods (63.7%), suggesting a decline in the regional population. The relationship between a decline in AoO and population size is however not always linear and the confidence in this population decline is low. However, it is suspected that the decline is greater than 30%.
The Black Stork is reliant on shallow waterbodies, such as estuaries and rivers, in which it forages (Chevallier et al. 2008). The degradation of wetlands and the damming of small rivers have undoubtedly had a negative impact on this species. Individuals sometimes collide with power-lines. Black Stork have been persecuted at commercial fish farming operations (DG Allan pers. comm.).
There are currently no species-specific conservation interventions underway for this species. The Black Stork is listed as Vulnerable under the National Environmental Management Act Biodiversity Act 10 of 2004 and as well as the Swaziland Game Act of 1991. It is placed in the Fourth Schedule: Specially Protected of the KwaZulu-Natal Nature Conservation Management Amendment Act No. 5 of 1999.
The location of nest sites needs to be ascertained and measures put in place to minimise the amount of disturbance at these sites. Efforts to reduce environmental impacts on the flow of perennial rivers in the region need to be supported.
* A review of the distribution, population size and demographic trends of the Black Stork in the region is urgently required.
* The genetic status of the southern African population, in relation to its apparent isolation with reference to populations occurring in northern Africa and Europe, should be ascertained.
* An assessment of factors influencing survival and nesting success should be undertaken, and potential threats identified so that mitigation strategies may be put in place.