Breviceps mossambicus Peters, 1854
Original Published Description:
Flat-faced Frog (English), Mozambique Blaasop (English), Mozambique Rain Frog (English), Moçambique Rain Frog (English), MoZambique Rain Frog (English), Flat-faced Rain Frog (English), Mozambique Short-headed Frog (English)
The distribution of B. mossambicus includes southern Tanzania, Malawi, Mozambique, Zambia, Zimbabwe, and eastern Botswana (Poynton and Broadley 1985a). The species is also found in South Africa, Lesotho, and Swaziland (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
Females reach up to 52 mm in snout-vent length (Harper et al., 2010).
A robust frog with extremely short legs and a short snout. The dorsal color is variable, but is usually gray-brown with dark specks. A dark mark extends from the eye to the arm, obscuring the tympanum. The ventral surface is smooth with a marbled brown pattern on a white background. In males the throat is darkly pigmented. Toes are unwebbed and the two outer toes of each foot are reduced (Harper et al., 2010).
Passmore and Carruthers (1995) note that B. mossambicus exhibits considerable intra- and inter-population variation in colour and markings. Most individuals have light paravertebral and dorsolateral patches differing, in this respect, from the northern Mozambique populations of the species. Because similar markings are also present in B. sopranus, B. bagginsi and B. adspersus, this character is of little diagnostic value. It has been found that mossambicus and adspersus hybridize extensively in sympatry (areas where the two species overlap) (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
This species is very similar in appearance to B. fichus, but the calls are distinctly different. It is thought that the two species do not overlap in range (Harper et al., 2010).
Habitat and Ecology
B. mossambicus is primarily a savanna species, but it can be found in a wide range of habitat types, including open woodland and mountain sides at elevations up to 1800 m. It tolerates a degree of habitat alteration (Harper et al., 2010).
This species inhabits parts of the Savanna and Grassland biomes where the annual rainfall exceeds 700 mm. Vegetation types include Moist Sandy Highveld Grassland, Moist Upland Grassland, Short Mistbelt Grassland and North-eastern Mountain Grassland. The soil is usually shallow, well drained, humus-rich, and often rocky. Minter (1997) indicates that during dry periods these species spend the time below the surface, often under rocks or next to the foundations of walls, where soil moisture levels are higher (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
After good rains, adults often emerge in large numbers from their places of concealment, to feed on alate termites. At such times, many are killed on the roads (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
A sticky substance is secreted during amplexus, allowing the male to become temporarily glued to the female. Large unpigmented eggs are laid in terrestrial burrows. Clutches are relatively small, usually consisting of no more than twenty eggs. Non-feeding tadpoles hatch six to eight weeks later and complete their development in the nest (Text from Harper et al., 2010).
Most breeding takes place in spring or early summer after soaking rains, although strong choruses sometimes form after rain at other times of the year. Once the species pairs amplexus is by adhesion and oviposition takes place in a chamber below the soil surface. Nests excavated near Wakkerstroom were located below loose rocks on the hill slopes or under old, dry tree trunks. Females remained in the vicinity of the nests, which contained 20–25 eggs (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
Males call at ground level from leaf litter or from the mouth of burrows (Harper et al., 2010). Channing and Howell (2006) describe the call as “a short chirp, 0.05 s long”
In overcast or misty conditions, calling may continue unchecked for several days and nights (Minter 1998). Calling activity is also influenced by temperature: the chorus intensity usually drops in the early hours of the morning when temperatures are low, but increases again after sunrise, and persists until mid-morning, even on clear, hot days. Minter (1997, 1998) found that during the day, calling usually takes place from well-concealed, shallow depressions, but at night males often move about on the surface, calling from one location for a while before moving to another (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
Emerging metamorphs are 8-9 mm (Harper et al., 2010).
Metamorphosis was completed after 6–8 weeks (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
IUCN Red List Category and Justification of Conservation Status
This species is widely distributed in a variety of habitats and does not appear to be at risk. It occurs in a number of provincial nature reserves and national parks (Text from Minter et al., 2004, © SI/MAB Biodiversity Program).
- Engystoma granosum Cuvier, 1829 (synonym)
- Bufo (Engystoma) granosus Cuvier, 1829 (synonym)
- Systoma granosum — Parker, 1868 (synonym)
- Breviceps mossambicus var. mossambicus — Werner, 1903 (synonym)
- Breviceps mitchelli Hoffman, 1944 (synonym)