Arthroleptella ngongoniensis Bishop and Passmore, 1993
In the description of this species, the authors (Bishop and Passmore 1993) recommended that it be classified Vulnerable. Harrison et al. (2001) indicated the species as Critically Endangered in view of its small area of occupancy (<10km2), rapid rate of habitat loss (>50% over the past 50 years) and an estimated global population size of less than 2500 individuals in six fragmented and isolated sub-populations (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
The small size of the adult frog (16–22 mm), coupled with the softness of its call, probably explain why this species remained undetected until fairly recently. The dorsal colouration is fairly consistent with no sexual dimorphism, being a sandy to golden brown background with four indistinct stripes composed of small dark brown spots. A broad, dark brown stripe (bordered ventrally and dorsally by a thin white/silvery stripe) begins at the tip of the snout and passes through the nostril, eye and tympanum to end at the axilla. The belly is white, while the ventral surfaces of the limbs and throat are pale yellow (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
Although there are no documented accounts of predators, these are likely to include snakes, other frog species and invertebrates, while prey includes ants, termites, insect larvae, and other small invertebrate characteristic of the grassland leaf litter (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
Bishop and Passmore (1993) describe A. ngongoniensis as being endemic to a small area of mistbelt on the eastern escarpment in KwaZulu-Natal and the Eastern Cape of South Africa (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
The breeding and non-breeding habitat is in Short Mistbelt Grassland, Moist Upland Grassland, and Afromontane Forest t occurs at altitudes in excess of 1000 m. Preferred sites are located on fairly steep slopes (30–40°) on either side of seepage channels, covered with a dense growth of indigenous grasses. Most of the known sites are surrounded by exotic tree plantations. The frogs are usually found at the bases of grass and sedge tussocks amongst a network of loose tunnels in the humus layer (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
Bishop and Passmore (1993) found the tadpoles undergo direct development, emerging as fully formed froglets approximately 27 days after egg laying (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
Eleven to 14 unpigmented eggs are laid on damp soil or vegetation at the bases of grass tussocks (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).