Family Phrynobatrachidae

Phrynobatrachus Günther, 1862

puddle frogs, cricket frogs, modderpaddas (A)

By A. Channing

Currently accepted name: Phrynobatrachus indet.
Red listing status:

Description

The genus name is derived from the Greek: phryne = toad; batrachos = frog.

Most species of Phrynobatrachus are less than 30 mm in length. The southern African species are distinguished from all other small ranid frogs by the presence of a small tubercle about mid-way along the tarsus. Species are generally brown with lighter and darker markings. Stewart (1974) has shown that there is a correlation between the pattern of markings and habitat type. Some forest-dwelling species have disks on the toes to aid climbing.

The tadpoles are large, bottom dwelling, and of typical ranid type with keratinized jaw sheaths and many rows of labial teeth.

Distribution

The genus Phrynobatrachus contains some of the most wide-ranging and abundant species of African frogs (Poynton and Broadley 1985b). There are c.66 species found throughout sub-Saharan Africa, except in the arid southwest and the winter-rainfall region of Western Cape Province. Three species occur within the atlas region east of 24°E, from sea level to an altitude of 1800 m. One species, P. acridoides, appears to be very scarce in the atlas region. The atlas data are reliable.

Habitat

Members of this genus generally inhabit the Savanna and Forest biomes. The species in the atlas region occur along the subtropical east coast and lowveld, through to the inland grasslands and savannas of the temperate eastern plateau. These areas receive summer rainfall of 250–<1000 mm p.a. Phrynobatrachus species are able to tolerate human disturbance provided that suitable breeding sites are available. Breeding usually takes place in shallow, temporary water bodies with well-vegetated banks, or in the quiet backwaters of shallow, slow-flowing streams.

Life history

In wet areas these species may be active for most of the year, but in dry areas they are found only after the first rains, retreating to refuges as conditions become drier.

In the atlas region, breeding begins with spring rains and continues throughout summer. Calling activity increases after rainfall. Males call from the surface in open or well-concealed situations. Calling may be heard during the day and at night, and most species are easy to identify on the basis of vocalizations.

As is typical of most members of this genus, the eggs of the species in the atlas region are laid in water, where they float in a single layer (Hewitt 1937; Rödel and Ernst 2002). Presumably, this raises the temperature of the eggs and speeds development.

The adults feed on a wide range of small arthropods, and are preyed upon by several species of snakes (see species accounts), and other wetland predators.

Conservation

These widespread frogs are not threatened as a group, although habitat loss to housing and other development is a localized problem. Phrynobatrachus species play a major role as predators of mosquitoes and other insects, and in turn provide food for larger frogs and other predators. A decline in their populations would probably have a significant effect on wetland ecosystems.

None of the species in the atlas region needs special conservation attention.