Latest news:

Strandfontein development could push butterfly into extinction

The only colony of one of the world’s most endangered butterflies is within sight of an ambitious new urban coastal node

A large, multi-storey development proposed at Strandfontein could put one of the rarest butterflies in the world at even greater risk of extinction, and decrease endangered biodiversity for which Cape Town is famous.

The City of Cape Town is pushing forward with its plan to create a “coastal urban node” at what is currently the Strandfontein Pavilion, which will include more than 1,000 residential units, retail and recreational facilities, and an aquaponics farm.

But a few hundred metres to the north of the development, which is to take place on the southern side of the intersection of Baden Powell Drive and Strandfontein Road, is a colony of critically endangered butterflies, found nowhere else in the world, of which there are less than 50 individuals left.

The initial Conceptual Development Framework for the development, published in June 2022, has one paragraph mentioning the existence of the colony of butterflies, called the Barber’s Cape Flats Ranger (Trida barbarae bunta – formerly Kedestes barbarae bunta), and warns that Strandfontein Road cannot be realigned “for a better aspect to the development”.

This is also a concern of the Lepidopterist Society of Africa, which has supplied the consultants tasked with developing the Basic Assessment Report (BAR), Infinity Environmental, with maps showing the existence of the Barber’s Ranger’s host plant found on either side of Strandfontein Road.

A member of the Lepidopterists’ Society of Africa, Dave Edge, said the critically endangered Barber’s Ranger is reliant on swordgrass (Imperata cylindrica) for its lifecycle, and breeds on the large patches of this grass existing alongside both sides of the southern part of Strandfontein Road near the planned development. The road might have to take a higher volume of traffic if the development goes ahead, said Edge.

He said swordgrass is also vital part of the lifecycle of the False Bay Unique Ranger (Kedestes lenis lenis) which, although it has a larger overall range than the few hectares occupied by Barber’s Ranger, is also critically endangered, and the Strandfontein Road population is one of the largest still existing.

“Any widening of the southern section of Strandfontein Road between Spine Road and Punt Road will destroy much of the habitat available to both butterflies and bring them closer to extinction,” he said.

The South African National Biodiversity Institute (SANBI), states on its website that “heavier vehicular traffic on the Strandfontein road, which bisects the main colony, has increased the incidence of specimens being hit and killed by vehicles, and the amount of air-borne toxins and pollutants from exhaust fumes being released into the habitat”. SANBI also notes the increased the risk of fire in the area “caused by passing motorists disposing of smouldering cigarette ends”.

Need to maintain an ecological corridor

Currently, Infinity Environmental’s Pre-application Draft BAR published last month, makes no mention of Barber’s Ranger, as the colony falls outside the development footprint. Yet the development will “impact natural ecological processes and increase the risks to the last remaining population” of this critically endangered butterly, says Nature Connect CEO Anthony Roberts.

Roberts said swordgrass was found within the Dune Strandveld vegetation, and what Dune Strandveld remained, needed to be conserved. Not only would the Strandfontein development cover existing Dune Strandveld, but the City states in its Metropolitan Spatial Development Framework (MSDF) that it plans to have similar coastal developments at Monwabisi and Mnandi, which are also on this vegetation type.

Roberts says this stretch of Dune Strandveld from Muizenberg to Strand, was the last natural vegetation connection between the Table Mountain and the Hottentots Holland Mountain chains, providing “essential corridors for flora and fauna”.

As such, it was “ridiculous” to consider developing land along False Bay’s coastal strip, and the “securing of functional conservation corridors is essential in the face of climate change impacts”.

He said South Africa was a signatory of the United Nations’ Convention of Biological Diversity, which had targets that included ensuring at least 30% of coastal areas, particularly those important for biodiversity and ecosystem functions and services, were conserved by 2030. Signatories are also commited to halting “human induced extinction of known threatened species” and to “significantly reduce extinction risk”.

Yet, said Roberts, South Africa had failed to protect the minimum 30% of Dune Strandveld, which was a City failure, as it fell within the municipal area. “A great deal of False Bay Dune Strandveld has been destroyed and any remaining patches should be secured at all costs,” he said.

“There is still a surprising amount of fauna that still utilise this strip for movement, such as caracal, grysbok, porcupines, genet, mongoose. They have also recently found increased honey badger activity on Table mountain and there is a good chance these animals have come in along this coastal strip.”

A 2017 report by Stellenbosch University Distinguished Professor Michael Samways on the conservation of biodiversity in and around Cape Town, highlighted the need for natural corridors to protect biodiversity and ecological functioning.

Samways states the loss of biodiversity and ecosystem function is a “major concern worldwide”, and such losses were likely to be “particularly acute” in Cape Town as it was part of a global biodiversity hotspot.

“Furthermore, the Cape Flats Dune Strandveld faces a high level of threat, with certain vegetation subtypes highly threatened and urgently in need of protection,” states Samways.

Need for further studies

Cape Nature land-use scientist Ismat Adams, who has written a Master’s thesis on the Barber’s Ranger, recommended a specialist determine whether swordgrass occurs on the development site, and if it does, a butterfly assessment should be done. This would determine whether “no-go areas” should be established.

Cape Town deputy mayor and mayco member for spatial planning and development, Eddie Andrews, said the existing colony of Barber’s Ranger was outside the development area.

“The population referenced in the comment occurs north of Baden Powell Drive while the proposed Strandfontein Coastal Urban Node occurs south of Baden Powell Drive. This is a considerable distance (approximately 1km) outside of the proposed site boundaries and the proposed development is, therefore, not anticipated to impact the habitat of the butterflies,” said Andrews.

He said comments received from the Lepidopterists’ Society of Africa highlighted concerns about widening Baden Powell Drive to accommodate additional traffice to the development. “This concern is noted and will likely form part of considerations if and when Baden Powell Drive is widened in future,” he said.

Lack of protection

Roberts said Nature Connect – formerly the Cape Town Environmental Trust – were involved in a three-year conservation project for the Barber’s Ranger from 2018 to 2020 in collaboration with the City. He said the project had been funded by the Mohamed bin Zayed Foundation and the Brenton Blue Trust, but when funding from Leisure Charitable Trust, which paid the project manager’s salary, came to an end, the project had to be shelved.

He said they tried to breed the Barber’s Ranger in a controlled environment but were unsuccessful. As there were so few individuals left in the wild, removing more to continue the breeding efforts would impact the remaining population, so they shifted to breeding the Cape Flats Ranger, which have a wider distribution. He said they had “some success” with that.

Although the City of Cape Town’s own Biodiversity Report of 2018 states there is a need to protect biodiversity, and conserve threatened species, Adams said he was not aware of any current management plan for the Barber’s Ranger.

The City did not respond to the question on what it was doing to ensure the continued existence of the Barber’s Ranger.