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).
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).
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).
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).
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).
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).
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).