Although the African marsh harrier is currently considered of low conservation concern (1), it is thought that the bird’s extensive range may mask a declining population (4), and a number of likely threats to the species have been identified.
Extensive drainage, burning, and grazing associated with the spread of human settlements has led to a significant loss of wetland habitats throughout the harrier’s range (4). In particular, the KwaZulu-Natal area in South Africa has been intensively drained and the Okavango Delta, thought to be the stronghold of the species, is also threatened (5). Even where wetlands are apparently still intact, habitats are often degraded and may have become unsuitable for the harrier (6). Continuing intensive pesticide use poses an additional threat to the African marsh harrier (4). Residues of chemical pollutants including DDT have been found to accumulate in harrier eggs and may be responsible for reduced hatching success (5).
Due to a lack of accurate records of African marsh harrier populations, the influence of these factors on the bird’s status cannot be confirmed, but it is widely assumed that its numbers are in decline (4) (6).