AMPHIBIAWEB
Natalobatrachus bonebergi
Boneberg's frog
family: Pyxicephalidae
subfamily: Cacosterninae

© 1998 Miguel Vences and Frank Glaw (1 of 3)

Country distribution from AmphibiaWeb's database: South Africa

View distribution map using BerkeleyMapper.


Conservation Status (definitions)
IUCN (Red List) Status Endangered (EN)
See IUCN account.
CITES
Other International Status None
National Status None
Regional Status None

   

From the Encyclopedia of Life account:

Distribution

N. bonebergi is endemic to the South Africa, Lesotho, and Swaziland region and restricted to the coastal forests of southern KwaZulu-Natal and northern Eastern Cape provinces, at altitudes below 900 m (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: du Preez, L.H.
License: http://creativecommons.org/licenses/by-nc/3.0/

Morphology

N. bonebergi is usually brown, but may be light to greenish brown. The snout is pointed, projecting markedly over the lower jaw. The fingers and toes are long with large, truncated, terminal discs, and the toes are slightly webbed. The back has elongated skin ridges, and a light vertebral stripe is often present. A distinct black stripe runs from the tip of the snout, through the lower part of the eye to the arm (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: du Preez, L.H.
License: http://creativecommons.org/licenses/by-nc/3.0/

Size

This is a small- to medium-sized frog, females reaching 37 mm and males 25 mm in length (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: Zimkus, Breda
License: http://creativecommons.org/licenses/by-nc/3.0/

Habitat and Ecology

N. bonebergi is always associated with forest streams and pools with rocky beds especially, but not exclusively, in ravines (Harrison et al. 2001). Typically, the frogs inhabit streams with short, fast-flowing sections alternating with longer sections of slow-flowing water and pools of varying size and depth (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: du Preez, L.H.
License: http://creativecommons.org/licenses/by-nc/3.0/

Modes and Mechanisms of Locomotion

These frogs are strong jumpers and can be difficult to catch. They take readily to water, swim well, and usually dive to the bottom where they hide in rotting plant material (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: du Preez, L.H.
License: http://creativecommons.org/licenses/by-nc/3.0/

Metamorphosis

After six days, the tadpoles are ready to wriggle out of the egg mass that becomes more liquid and sags downward. On hatching, tadpoles drop into the water to complete their development. Tadpoles are benthic and can complete metamorphosis in 60 days (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: du Preez, L.H.
License: http://creativecommons.org/licenses/by-nc/3.0/

Reproduction

Breeding takes place October–May, along shallow streams with overhanging vegetation. Males select perches c.1–2 m above the water, from which they utter their faint advertisement calls. Amplexus is axillary with the fingers of the male placed below or sometimes above the base of the female’s arms. Transparent masses of 75–95 eggs are attached to leaves, twigs, tree trunks, or rock surfaces overhanging pools. Egg clutches are vulnerable to desiccation; in dry conditions the female moistens the clutch with liquid from her cloaca (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: du Preez, L.H.
License: http://creativecommons.org/licenses/by-nc/3.0/

IUCN Red List Category and Justification of Conservation Status

Harrison et al. (2001) suggest that in view of its restricted distribution (area of occupancy = 11–500 km2) and rate of habitat loss (>50% in the past 100 years), it has been accorded Endangered status (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).


Author: du Preez, L.H.
License: http://creativecommons.org/licenses/by-nc/3.0/