Monday, 12 September 2011

Black Stork possibly in trouble

In the account for the Black Stork in the Red Data Book from 2000, Keith Barnes wrote: "The Black Stork may suffer a decline in the near future and, owing to its small population, it requires monitoring." This range-change map shows that these were prophetic words. Keith considered that the breeding habitat, in mountainous regions was not threatened, but that the crunch was going to be food: fish, frogs, aquatic invertebrates. "Wetland conversion in the form of degradation of estuaries and highland marshes, the afforestation of catchments which reduces water inflow, and the damming of smaller rivers, such as in Lesotho and Mpumalanga, are causes of concern."

SABAP2 (2007–2011) probably represents the first monitoring of the Black Stork since SABAP1 (1987–1991), and the outcome is alarming. The species has not been recorded in SABAP2 in any of the quarter degree grid cells coloured RED in this map, and reporting rates have decreased in all the cells coloured ORANGE. ORANGE and RED are far and away the dominant colours on this map. There are large tracts of its former range where there have been remarkably few SABAP2 records, for example in the Overberg and Swartland areas of the Western Cape.

It is remarkable that a species as large and conspicuous as the Black Stork can quietly slip away unnoticed. This demonstrates once again the value of SABAP2, and the importance of making SABAP2 a continuous and ongoing broad brush monitoring project. We still need more birders to be involved! And resources to keep the project running into the long-term future.

Source: SABAP2/ADU

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