African marsh harrier  (Circus ranivorus)

Classified as Least Concern (LC) on the IUCN Red List (1) and listed on Appendix II of CITES (3).

The smallest of all marsh harriers (4), the African marsh harrier has brown-orange plumage on its body, speckled with white, often with darker, chestnut brown feathers on the chest. The upper surface of the wing is grey-black, whilst the underside of the wing has a distinctive pale patch at the shoulder which is visible in flight. The bill is black with a yellow cere, and the iris and legs are also yellow (2).

The African marsh harrier is endemic to southern and eastern Africa (2), where it is found across an extremely large range of approximately three million square kilometres (5). The Okavango Delta in northern Botswana is thought to be the species’ stronghold (5).

This species breeds and forages in tropical wetland habitats including marshes, floodplains, reed beds and lake margins (2) (6).

The African marsh harrier is considered a water bird (4), breeding and foraging amongst reedbeds and marshlands around water bodies (5) (6). The breeding season usually extends from August until December, although there is regional variation and year-round nesting has been reported in northern South Africa (4) (6). The nest is constructed from sticks and rushes and situated within areas of thick, marshy vegetation. Between three and five whitish-blue eggs are laid, which the female incubates for 30 days whilst the male brings food to the nest (2).

Small mammals, in particular the striped mouse (Rhabdomys pumilio), are the African marsh harrier’s main prey, makingup more than 70 percent of their diet (4). However, the species will also eat frogs and small wetland birds and may even raid the nests of herons and egrets to eat young chicks (2) (6). Foraging is carried out over reeds, lake margins and floodplains (4) (5), and the bird may spend hours on the wing, seldom alighting (2).

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).

Due to its exceptionally large range, the harrier is listed as a species of Least Concern on the IUCN Red List (1).  However, an estimated 20 percent loss of wetland habitat, and growing recognition that the species’ wide distribution may hide a declining population, means that the harrier has been elevated to Vulnerable status in South Africa (6). There are currently no conservation programmes specifically for the African marsh harrier, although the East Caprivi wetlands in Namibia (an important population stronghold) have recently been designated an Important Bird Area (6), an area designated by BirdLife International as a key site for conservation (5).

View information on this species at the UNEP World Conservation Monitoring Centre.

To learn about efforts to conserve raptors, see:

• The Peregrine Fund:
  http://www.peregrinefund.org

For more information on this and other bird species please see:

• BirdLife International:
  http://www.birdlife.org