Rare butterfly on the brink of extinction

Strandfontein is home to two highly localised and threatened butterflies, the Barber’s Ranger (Kedestes barberae bunta) and the Unique Ranger (Kedestes lenis lenis). They belong to a specialised group of butterflies known as skippers and are interesting in their adaptation to the strong winds that often blow across the Cape Flats, as they “skip” from one patch of plants to another.

Earlier this year might have seen UCT Master’s student Ismat Adams spent some time darting around the veld in Strandfontein patiently counting these butterflies as part of his thesis. .

“Although there were records of this species in Retreat, very few had been seen in recent years and little was known about the location of their breeding sites,” says Ismat.

He compiled a management plan for these butterflies with a goal to draw them back from the brink of extinction.

His thesis completed, he left the project which was taken over by the Westlake based Cape Town Environmental Education Trust (CTEET).

The Unique Ranger is classified as endangered and is found at a few sites in the south western corner of the Cape Flats and at a site near Worcester.

Ismat says Barber’s Ranger previously lived around Steenberg railway station, now under houses.

The Barber’s Ranger has more limited distribution with only about 50 left flying around patches of cottonwool grass (Imperata cylindrica grass) beds found among Cape Flats Dune Strandevld in the Pelican Park section of the False Bay Nature Reserve.

Because they are found nowhere else on the planet they are classified as critically endangered, which means that given the present trends, its extinction could be imminent. They are threatened by habitat destruction, invasive alien vegetation and too frequent fires – one wild fire could wipe them out. Another threat is that one of the Cape Flat’s busiest roads, Strandfontein Road, runs through their habitat and has been widened.

CTEET voluntary project manager, Louise Baldwin says they are notoriously difficult to rear and very little research has been done on skipper butterflies worldwide.

Because of this, a Kedestes Conservation Committee has been formed to look at conservation action to save these two species. The committee is made up of CTEET, the City’s Biodiversity Management Branch, the Western Cape Branch of the Lepidopterists Society of Africa, Professor Mike Piker at UCT, and the Brenton Blue Trust with collaboration with a zoo in Minnesota, in America.

For the past week Louise and the team have been examining every blade of cottonwool grass alongside a stretch of Strandfontein Road. They are searching for eggs laid by the butterfly and then pegging and plotting their finds.

Louise says the caterpillar crawls up the blade of grass, folds it over and ties itself into a cosy web. When it has eaten enough it moves on to another blade. It does this between November to September, for almost a year and is on the wing from October to November. Barber’s Rangers have a wingspan of 26mm to 33mm for males and 29mm to 38mm for females, with adults on the wing in September.

CTEET field assistant Robyn Morton says they are building an enclosure at their base at Zandvlei where the eggs have a better survival rate and can bolster the butterflies’ numbers before being released back into the wild.

“The project is also a great opportunity to raise awareness within thelocalcommunities about the threatened species and their importance as part of Cape Town’s unique biodiversity,” said Louise.

“Once we get this right we’ll hopefully do the same with Barber’s Ranger.”

“Like other butterfly species around the world, it is hoped that these butterflies will helphighlightthe plight of the unique natural heritage of the Cape Flats which is under threat,” he says.

Louise says this little butterfly might not be a panda but it is still worth saving.