Kloof Frog
Natalobrachus bonebergi
Amphibian
| At a Glance | |
| Size | 37mm (F) 25mm (M) |
| Mass | |
| Lifespan | 5 years |
| Conservation Status | Endangered - In view of its area of occupancy of less than 500 km2, its distribution is fragmented |
Description
The back is light greenish-brown to grey, sometimes with pale spots and a pale vertebral line. A distinctive black stripe runs from eye through the lower part of the eye, down the arm. This band is bordered below by a narrow white band along the upper jaw. Pointed snout which protrudes over the lower jaw. The underside is cream-coloured. Fingers and toes are long and end in large discs. Toes are slightly webbed.
Behaviour
Agile jumpers and strong swimmers, enabling them to escape easily and hide in rotting plant material at the bottom of pools. Expanded adhesive toe-tips (‘T’-shaped) allow easy movement over vertical rockfaces and slippery surfaces.
Diet
Insects (tadpoles feed on algae)
Breeding
From Oct - May male frog chooses a perch 1 - 2m above the water in overhanging vegetation. He makes a faint ‘clicking’ advertisement call. Female responds and clutches of 75 - 95 eggs are laid in clear masses attached to leaves, branches or rocks above water. The female keeps them moist with fluid from her cloaca. Tadpoles develop inside the jelly mass and 6 days later emerge and drop to the water below. Metamorphosis is complete within 60 days.
Distribution
Restricted to rocky streams in coastal and gallery forests of northern Eastern Cape (from Dwesa Nature Reserve) and eastern KwaZulu-Natal. It occurs below 900 masl.
Habitat
Rocky streams in coastal forests and gallery forests , alternating with fast-flowing sections and larger tranquil pools with a gravel bed are preferred. It breeds in streams, hanging its eggs above water on branches, and sometimes on rock faces. The larvae fall into the water where they develop. It does not survive in open areas.
Threats
Afforestation as a result of sugar plantations and housing developments have encroached on the specialised habitat of the species. It is also threatened by pollution and siltation of streams.
Local Information
It occurs in several protected areas, including Krantzkloof, Umtamvuna Nature Reserve and Oribi Gorge Nature Reserve.
Interesting Facts
This is a monotypic species – i.e. the only species in its genus (Natalobatrachus). It is most closely related to the Marsh frogs of the Western Cape. It was described in 1912 and named for Father Bonebergi from the Marianhill Monastery who discovered the species at ‘Mariannhill’ (probably Krantzkloof).
Sound
A sound clip is available on SoundCloud.