OVERBERG RENOSTERVELD TRUST

Black Harrier research: More satellite tags urgently needed

R67 000

Our sincere thanks to you. With your incredible support, we have raised R67,000 for satellite tags for Black Harriers in 2024. With additional support from ENGIE, we are now able to acquire six new tags. These will help us monitor Black Harriers, to better understand their threats.

We have also already named some of our tagged birds after our donors and volunteers. One harrier was named in honour of Valerie Gargett, well-known Verreaux’s Eagle biologist, by Peter Steyn shortly before he died. The second was named by Michael Raimondo for his father, the late Frank Raimondo, a man who cared deeply about conservation and about wild things and wild places. A third tagged bird was named Tony, as a thank you to our Dutch volunteer, Toni Hoenders, who has helped the ORT over the past two years with mapping out the harrier breeding sites in the Haarwegskloof cluster.

But the work is not done. Please continue to support this cause, so that we don’t lose these majestic birds from our landscape forever. In 2025, we hope to acquire even more tags as we focus on the movement of fledglings as they mature.

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Banking details: Overberg Renosterveld Trust

Nedbank
Acc no. 1092736514
Branch code 198765
Swift code NEDSZAJJ

Reference: #blackharrier

Or contact Odette at info@overbergrenosterveld.org.za
or call + 27 (0) 83 551 3341

Saving Black Harriers from extinction

Black Harriers are rarer than rhinos. With only around 1,300 of these majestic birds remaining, we could lose this species in our children’s lifetime.

The Overberg Renosterveld Trust is working with partners to address this crisis to Black Harriers. In 2021, we started a project to place satellite tags on Black Harriers. To date, we have tagged 15 Black Harriers in the Overberg, and have contributed to the tagging of five more birds outside the Overberg with Dr Rob Simmons around future wind farms.

From the data we have collected, it’s become clear that Black Harriers are in dire straits. If we’re to save Black Harriers from extinction, we need to tag more birds, ESPECIALLY around current and future wind farms.

That’s why we’re asking you to get involved, to help us secure four more satellite tags and to support additional surveys.

Incredible data have been collected already on what the birds are doing inside and outside the breeding season. And we are gaining critical insights into adult mortalities. Of the 15 Overberg tagged Black Harriers, two were killed by wind turbines, one by a wheat-cutter and one by an aerial predator.

Data collected already played a key role in wind farm developers introducing higher levels of mitigation for the species.

Now we urgently need to continue and expand upon this research, by placing satellite tags on more birds and undertaking additional surveys.

2022 PREVIOUS BLACK HARRIER CAMPAIGN: RAISED R 177 014

Support this campaign

Make Your Donation

Please consider donating to this Black Harrier Project. Funds go entirely to buying satellite tags. If you sponsor a tag (worth R25,000), you will be able to name ‘your’ bird, and we’ll display your corporate or other logos on our website.

We cannot let the imperilled Black Harriers go extinct on our watch. Please support this critical work.

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Protecting Black Harriers: Threats and solutions

A total of 15 Black Harriers have been tagged with GPS trackers since 2020, which have led to a number of eye-opening discoveries regarding this Endangered species. Chief among these is just how reliant Black Harriers are on renosterveld, but also how many threats they face every time they take to the skies.

The Overberg Renosterveld Trust has partnered with harrier guru Dr Rob Simmons of the University of Cape Town, Dr Megan Murgatroyd of Hawkwatch International, Prof Arjun Amar at the FitzPatrick Institute of African Ornithology, UCT, as well as with BirdLife South Africa and the Endangered Wildlife Trust to better understand Black Harriers, how they move and forage, and the greatest threats facing them.

We first tagged two Black Harrier males in 2020. These males were all breeding on a renosterveld site situated close to the Excelsior Wind Farm, near the town of Swellendam. This is likely one of the largest breeding colonies of Black Harrier on the planet. Over the next two to three years, 13 more Black Harrier males were fitted with satellite trackers.

And that’s when we really started to understand these iconic renosterveld species better.

The data from the satellite tags showed us that Black Harriers in the Overberg could easily cover 30km foraging in one trip. Given the incredible loss of renosterveld, Black Harriers are also hunting over wheat fields during these trips, although most of the rodents that they feed on occur in natural habitats.

It was also only through satellite tags that we could gather data on mortalities. In fact, two Black Harriers were killed close to each other, in the space of a day, in the Overberg. Both these birds were tagged – and both were killed via man-made activities. The first died in a collision with a wind turbine on the wind farm, and the second was killed by a grain-cutter. Since then two more tagged Black Harriers have been killed: A wind turbine was responsible for the death of another bird, while a fourth Black Harrier was killed by an aerial predator.

Our urgent appeal – we need to find out more

While we have learnt a lot from the 15 tagged Black Harriers, it’s vital that this research is continued, and expanded on.

The focus is especially on fitting tags onto birds around existing wind farms, as well as areas where wind farms are being touted in the future. We have already been able to use the data from our birds to appeal approvals on some local wind farms: This resulted in some developers opting to amend Environmental Management Programmes to ensure higher levels of mitigation for the species. It will also help us to use good science to back any objections or comments that we may need to submit related to applications for new wind farms, particularly in the Overberg. Therefore, the more data we have, the more we can motivate to developers to bring in steps to completely stop harrier (and other species’s) collisions with turbines.

Those who are interested in sponsoring a tag (worth R25,000) will be able to name their bird, and their corporate or other sponsors’ logos will be displayed on our website.

FIND OUT MORE HERE

How is it possible that Black Harriers are facing extinction?

Models suggest that harrier numbers are declining by 2.3% a year, and that fewer than 1,300 mature individuals remain currently. That’s why they are globally and regionally listed as Endangered. In fact, they’re considered to be one of southern Africa’s most threatened raptors.

Modelling data from Dr Simmons and Dr Francisco Cervantes Peralta of the University of Cape Town has found that if three adult Black Harriers are killed every year by wind turbines around South Africa, the species will be extinct in 100 years. Should five birds be killed by turbines per year, then Black Harriers will be extinct in just 75 years.

These threats are all the more urgent given that the entire wheatbelt (the renosterveld region) of the Overberg has been identified by government as a Renewable Energy Development Zone, meaning we will see a lot more new wind farm developments in the region relatively soon. While this is important for climate change mitigation, it’s incredibly bad news for harriers. In fact, statistics show that harriers have experienced high mortality rates on wind farms elsewhere in South Africa. The Overberg is a hotspot for harriers and they are one of the most high-risk species for collisions with turbines, which means this ‘green energy’ may end up placing the species at an even higher risk than current models predict.

At the same time, Black Harriers have suffered severe loss in their preferred breeding grounds: renosterveld. Around 95% of renosterveld has been converted, mostly for agriculture. As a result, harriers have far fewer safe breeding opportunities.

Breeding Black Harriers: Why every bird counts

Black Harriers breed on the ground, often in large colonies, from around September, but they may also breed earlier in the year if prey numbers (small mice) are good. While feeding chicks, they are most at risk as they forage a lot more, and thus may spend more time in and around the wind farms (as they make no effort to avoid them). They lay between three and five eggs. The females incubate the eggs for about a month, while the males find the food and feed the female throughout the incubating period. Once the chicks hatch he also has to forage for her and their small chicks until she starts contributing to foraging when it is safe to leave the nest for short periods.

Our most recent discovery of a colony of Black Harriers was made in a patch of renosterveld close to a wind farm. This is likely to be one of the largest breeding colonies of Black Harriers in the Overberg, and we remain incredibly concerned for the species. Should a male Black Harrier be killed for any reason, the young chicks will also die with the loss of the food provider.

Images: Chris van Rooyen

Possible solutions to seemingly insurmountable challenges

There are many solutions that are vital to the Black Harrier’s survival. A shutdown-on-demand programme at the Excelsior Wind Farm, owned by Engie, means that when paid observers identify threatened species flying towards a particular wind turbine, they radio into the control room and the turbine is immediately switched off. This has undoubtedly saved the lives of many birds of prey, with between 200 and 550 successful shutdowns a year since 2021. Following the death of two Black Harrier at a wind turbine on this wind farm, additional measures were put in place, including doubling up on observers at a challenging vantage point.

Aside from the short-term measures to protect birds at wind farms, there are also other methods which eliminate the potential for human error, which have proven to reduce collisions by 100% in some areas: for example, painting one of the turbine blades (or two-thirds of it) black, which makes the turning blades highly visible to birds. This idea has been tested in Norway and was found to be 100% successful with no running costs. It urgently needs to be tested elsewhere, including more testing in South Africa. Much work still needs to take place before such interventions become common practice. Other mitigation measures such as the automated shut down are extremely costly and difficult to implement post-construction, thus the ORT and others are pushing for further consideration of the black blade option.

Contact us

Contact Odette at info@overbergrenosterveld.org.za
or call + 27 (0) 83 551 3341

Our webinar with BirdLife South Africa

Dr Rob Simmons and I participated in the BirdLife South Africa Conservation Conversation webinar on Tuesday 28 June 2022. We discussed Black Harriers, their threats, and what we’re doing to protect them.

WATCH THE RECORDING HERE

The ORT has adopted a two-pronged approach to Black Harrier conservation:

The first is to secure Black Harrier breeding grounds in renosterveld through conservation. The ORT has focused on signing conservation easements with farmers, with an emphasis on those with Black Harrier breeding sites. Though this, sites important for harriers will be protected in perpetuity.

The second is to carry out research on how the species uses the landscape for foraging, by fitting breeding adults with satellite tags. If we know this, we can put conservation measures in place to protect them, including preventing wind farms planned in Black Harrier flight paths, or assisting those that exist with mitigation measures to avoid turbine collisions.

In 2022, we asked our donors and supporters to help us raise funds for satellite tags. We asked for funds to buy three tags initially. But thanks to an overwhelming response, we secured sufficient funds for eight tags. Here are our top supporters from our 2022 campaign:

The Tygerberg Bird Club (3 tags)
The Overberg Crane Group (1 tag)
Rob Simmons’ grant from the National Research Foundation (1 tag)
BTE Renewables (Excelsior) (1 tag)
The Dutch Montagu’s Harrier Foundation (1 tag)

For ORT Director, Dr Odette Curtis-Scott, Black Harriers paved the way to the creation of the ORT. She says,

“From a very young age, I was drawn to birds of prey, which introduced me to what is arguably South Africa’s most charismatic raptor. Since 2000, I have been involved in studying Black Harriers and the renosterveld habitats on which they depend. Yet there is so much that we need to still understand about the species, and its relationship with its preferred fynbos and renosterveld habitats, if we are to save them from an otherwise very gloomy future.”

Black Harrier Fast Facts

Black Harriers regularly move up to 16 km from their nests.
One foraging trip by a tagged Overberg male encompassed 33km around his nest.
Post-breeding, they can fly up to 400 km in a day and regularly move 1,200km to Lesotho for the summer months.
Pre-breeding they can move even further, up to 5,000 km in sampling trips over six months.
Black Harriers fly at speeds of around 40-60km per hour while migrating.
While harriers forage at heights of 2-5m, the 9g trackers show they reach heights of 600-800m above the ground.
Most wind-farm fatalities are recorded in October and November.
This occurs because more harrier flights occur in the blade-swept area than at other times of year.

Our role as a Black Harrier Species Guardian

In 2022, the ORT was chosen by BirdLife South Africa to become a Black Harrier Species Guardian. We join South Africa’s other Black Harrier Species Guardian, Dr Rob Simmons. This means that we are working with BirdLife South Africa to continue to take conservation action to protect these harriers. This is an exciting opportunity for the Trust, and wonderful recognition of our work to protect Black Harriers to date. The ORT is also currently chairing the Black Harrier Task Force, a collaboration with various NGOs including BirdLife South Africa, the Endangered Wildlife Trust and other specialists. Together we are working towards a Species Action Plan for Black Harriers throughout their range.