6th March 20236th March 2023 by Gondwana Conservation Foundation

Southern Africa’s Rarest Endemic Raptor ~ The Black Harrier

There is something so magical about the flight of the Black Harrier (Circus maurus) as it swoops over the fynbos silently hunting. The feathers are deep black with large white panels on the under wing and white bars on the tail feathers, that occasionally catch your eye as it glides over low growing fynbos.

According to BirdLife South Africa, there are “fewer than 1000 mature breeding birds left in the population. Studies have shown that there is little genetic variation across the population, indicating that this species is not in good shape and needs some serious conservation assistance going forward.”
Dr Megan Murgatroyd from Hawkwatch International with assistance from Dr Marie-Sophie Garcia-Heras (who has done her PhD on Black Harriers through her study of 400 nests over 15 years) visited Gondwana and initiated the study of Gondwana’s Black Harrier population.

Gondwana is home to a number of breeding pairs that nest in various locations on the reserve. During their visit the researchers, tagged a breeding pair with a GPS “backpack” and ringed the raptors on the top plains of Gondwana. This will assist us to learn more about their flight habits and breeding patterns in the region. Measurements were taken of their beaks, talons wings and tail. During the process the two researchers were pleased to encounter various juvenile fledglings in the same area.

Black Harriers have special characteristic features and behaviours. The females sit predominantly on the eggs while the males hunt. The males bring the food close to the nest and then exchange the food to the female in flight just above the nesting area – talon to talon. The females have a naked patch of skin on their chests called the brood patch used to keep the eggs warm. They feed on mice and birds, and breed on the ground, exclusively in low growing fynbos and renosterveld areas.

We look forward to having Dr Megan Murgatroyd & Dr Marie-Sophie Garcia-Heras back on the reserve as they further their research on the Black Harriers in the months to come.

The fynbos would not be the same without its own endemic raptor and the Black Harrier certainly claims that title majestically.

When the Harriers are caught a raptor hood is placed over their eyes to calm them down
and to reduce stress levels, during observation

Black Harriers (Circus maurus) are an important species for conservation as they are endemic to Southern Africa and listed as an endangered species. Gondwana Game Reserve is home to a number of breeding pairs, and so to monitor their behavior and success on the reserve, it is necessary to tag them.
Two Black Harriers were caught and tagged. It appeared to be a breeding pair as both a male and female caught. These can now be easily identified by the rings on their legs. The female was tagged with a blue ring around her right leg and the male was tagged with a blue ring around his leg.

Rings were placed on both legs. The colour ring is to help identify in which area the bird has been tagged (Blue tags for the Southern Cape) and the second ring is a unique number specific to this bird which is added to a database.

Both birds have been tagged with a GPS “Backpack”. The “backpack” is attached with Teflon strings and cotton stitches in the front. This is to reduce friction on the birds skin, the cotton degrades and the whole backpack can then fall off at the same time in about 3 years time. The purpose of this is to track their movement in and out of their breeding season and to determine their behaviour. This information will then be used to advise on how to mitigate wind turbine collision which is currently one of the largest threats to their ongoing survival. From this movement we will also be able to determine if these particular birds will return again next year to breed on Gondwana Game Reserve.

For each bird wing, tail, body, head, beak and leg measurements were taken.

The talons and beak were photographed next to a board with yellow in varying shades. This can be used to determine the “yellowness” which then relates back to how much of their prey would be other birds. The yellower their beaks and talons the more birds they have in their diet.

Sex of the birds were determined by looking for the brood patch which only the female would have.
This is an area where there is no feathers so that the skin can touch the eggs and keep them warm during brooding.

During their time on the reserve Dr Megan Murgatroyd & Dr Marie-Sophie Garcia-Heras were excited to observe the number of fledgling Black Harriers that were flying around our top plains. We look forward to hosting Meg and Sophie again in the future as they continue their work on Black Harriers.
Dr Megan Murgatroyd & HawkWatch International

HawkWatch International (https://hawkwatch.org) is an American NGO based in Utah. They work on a number of raptors in the USA. Dr Murgatroyd focusses on the international work for the organisation. She did her PhD on Verreaux’s (Black) Eagles in South Africa and has continued with her research on these eagles. Her concern for the impact that wind farms have on eagles and other raptors has led her to focus on Black Harriers. Her work on Black Harriers is being run in collaboration with the FitzPatrick Institute at the University of Cape Town.