I’m not really into frogs. I love their chirping and clicking, especially in misty conditions on the mountain when it imbues a sense of solitude to the landscape, but otherwise I am not particularly charmed by amphibians. That all changes when it comes to Heleophryne rosei, commonly known as the Table Mountain ghost frog, one of 19 frog and toad species that occur on the mountain.
What makes the ghost frog so special?
Primarily, its distribution: our specie occurs only in the swift-flowing sections of seven perennial streams on Table Mountain (all on the southern and eastern flanks), nowhere else on earth. That’s an area of about eight square kilometres. One of only two vertebrates endemic to the Cape Peninsula (the other also a frog), the ghost frog can truly be called a child of Table Mountain.
Heleophryne (Latin for ‘the one who is afraid of the sun’) rosei is one of the most ancient frog species, having split off from its closest ancestors more than 160 million years ago. Its solitary evolution on Table Mountain spans millions of years and gave it the niche habitat of swift-flowing streams by endowing it with suction pads on their toes, tiny skin projections that grip like Velcro, flattened bodies and highly webbed feet. Even the tadpoles are adapted to life in the fast lane, possessing sucker-like mouthparts that prevent them from being swept away by the current.
One of the coolest things about ghost frogs is a translucent belly that reveals their innards. This together with its scarcity and secretive nature account for its name. In fact, you’re almost more likely to come across a real ghost on Table Mountain than one of these guys. Two decades of hiking Table Mountain and I’ve only ever chanced upon one. They spend much of the day underwater, ensconced in nooks and crannies, only emerging at night to feed on insects.
How will you recognise a ghost frog?
If you find yourself along a fast-flowing stream on the south or east side of Table Mountain at dusk – or at night with a headlamp – and you come across a frog five to six centimeters long with enlarged toes and a striking skin coloration (pale green with purple spots) perched streamside on a mossy rock, then you’re most likely looking at a ghost frog. Congratulations. However, non-breeding adults occasionally do stray from streams and venture into marshes and caves.
Why is the Table Mountain Heleophryne rosei endangered?
Sadly, the ghost frog is set to become even more elusive, and might even face total extinction. Tadpole numbers in Skeleton Gorge (one of its habitats) have dropped by an estimated 50% since 1980. Not surprising that it’s listed as Critically Endangered. With an area occupancy of less than 10 square kilometers and a continuing decline in the extent and quality of its habitat, extinction is a very real possibility. In fact, it has already become extinct in some parts of the mountain. The main threats are the spread of invasive alien (non-indigenous) vegetation, frequent fires and the dams of the Lower Plateau (affect the consistency of stream-flow). Furthermore, poor forestry practices also contribute to the clogging of streams.
On a brighter note, Table Mountain National Parks is committed to the eradication of alien plants on the mountain – an ongoing programme that will benefit not only the ghost frog, but many other native plant and animal species.
While we won’t wager a bet that you will see the ghost frog when hiking Table Mountain with us, we can guarantee a superlative experience of the mountain with memories that will last a lifetime.