Happy Marsh Harriers flock to rewilded wetlands

In healthy wetlands you’ll find a healthy array of insects. These insects make great food for a healthy population of frogs. And flying over these wetlands, birds of prey such as the African Marsh Harrier feed on the frogs.

So as far as indicator species go, African Marsh Harriers are a great showcase for wetland health and integrity. In fact, these harriers are largely dependent on wetlands to breed and feed.   

But in South Africa, wetlands have not just been neglected; in many instances they have been actively drained, converted to agricultural lands or developments. 

That’s proven to be bad news for African Marsh Harriers, with population estimates suggesting a 20% decline in South Africa since 2007.  

Listed as Endangered 

The situation became so dire for these majestic flyers that they were listed as Endangered regionally – with Birdlife South Africa data suggesting only between 3 000 and 6 000 pairs remain. And numbers are still falling.  

What they therefore need – urgently – are healthy wetlands. And given that one African Marsh Harrier breeding pair needs around 100 hectares as breeding territory (according to Tarboton and Allan, 1984), they need sizable wetlands if their numbers are to stabilise and even increase.  

African Marsh Harriers are monogamous and although they don’t pair for life, they do remain together in the long term. What’s more, pairs often stay in the same territory to nest year after year.  

A Marsh Harrier flies across a Western Cape landscape. Photo: © Cliff Dorse

Conserving Species of Conservation Concern 

With funding support from the Hans Hoheisen Charitable Trust, Mapula Trust and the Table Mountain Fund, the Nuwejaars Wetlands Special Management Area (NWSMA) can focus on conserving Species of Conservation Concern such as African Marsh Harriers.  

Key to that is monitoring numbers, especially in sites that have been restored and rehabilitated. When we see how numbers change in subsequent years, it allows us to monitor the impacts of the rewilding work taking place here, and to see how bird communities are responding and how systems are being restored.  

Avifaunal expert, Eric Hermann, visited the Nuwejaars Wetlands SMA for two years in a row in October. His job? To survey African Marsh Harriers here to identify breeding and nesting birds.  

Above left, centre and below: Marsh Harriers photographed in the Nuwejaars Wetlands Special Management Area in October 2024. Above right: A Martial Eagle also made an appearance during two days of monitoring in October. Photos: © Eric Hermann