Family Ptychadenidae

Ptychadena uzungwensis (Loveridge, 1932)

Udzungwa Grass Frog, Udzungwa Ridged Frog, Udzungwa Graspadda (A)

By L.R. Minter

Currently accepted name: Ptychadena uzungwensis
Red listing status: Least Concern

Distribution

P. uzungwensis is recorded from Tanzania, Rwanda and Burundi, southward to Angola, Zambia, Zimbabwe and central Mozambique (Stewart 1967; Poynton and Broadley 1985b; Channing 2001). In the atlas region it is recorded from only three localities in the Soutpansberg, Limpopo Province: Bluegumspoort (2229DD), Entabeni Forest Reserve and Outlook (2230CD).

Poynton (1964) suggested that P. poyntoni Guibé 1960 from Inhluzane, KwaZulu-Natal, was based on a hybrid population of P. uzungwensis and P. porosissima, and placed P. poyntoni in the synonymy of P. porosissima. Jacobsen (1989) was of the opinion that the Inhluzane population probably reflected the range in variation within P. porosissima, rather than a hybrid population involving P. uzungwensis.

Habitat

P. uzungwensis inhabits medium- to high-altitude grassland at 800–2300 m in the vicinity of pools and seepages (Stewart 1967). It is adapted to a temperate climate and resembles P. porosissima in this respect. In the atlas region it was found sheltering among grass tussocks on a dolerite outcrop, at the edges of small pools, and in a seepage area above a stream, in Northeastern Mountain Grassland, at an altitude of c.1500 m. (Jacobsen 1989).

Life history

This species is inactive during the dry season. Loveridge (1953a) unearthed a dormant individual in August on the Lichenya Plateau on the southwestern side of the Mulanje Massif, Malawi. In the wet season, adults are found in the grass near their breeding sites. When disturbed, they take one long leap into a grass tuft and remain concealed. When captured they adopt a rigid posture, stiffening and straightening the hindlimbs and squeaking (Stewart 1967).

Apart from Channing’s (2001: 344) description of the call as “a typical trill”, details of the breeding biology of this species are unknown.

Food consists primarily of insects and spiders (Inger and Marx 1961; Stewart 1967) as well as snails and other frogs (Channing 2001).

Conservation

In the atlas region, P. uzungwensis has an extremely peripheral distribution and is known from only a few localities. It is threatened by habitat loss from afforestation and other agricultural activities. It enjoys some protection in Entabeni Forestry Reserve and possibly also on certain private reserves in the Soutpansberg.

Current distribution map

Undated records;  pre-1996;  1996 to 2002;  2003 to present