Family Hyperoliidae

Kassina maculata (Duméril, 1853)

Red-Legged Kassina, Rooibeenvleipadda (A)

By P.J. Bishop

Currently accepted name: Hylambates maculatus Duméril, 1853
Red listing status: Least Concern ver 3.1 (2013)

Photo by Evans Nick, 2014. URL: FrogMAP: 1733

Distribution

K. maculata is essentially a lowland species, although there is an unusual record of specimens from the Vumba Mountains (Zimbabwe) at an altitude of 1400 m (Poynton 1964). North of the atlas region, the species occurs throughout Mozambique and the eastern lowlands of Zimbabwe, Malawi, Tanzania and Kenya. In the atlas region, K. maculata ranges from Pafuri (2231AD) in northeastern Limpopo Province, through eastern Mpumalanga and eastern Swaziland to the coastal lowlands of KwaZulu-Natal, and south to Shakaskraal (2931AC).

Although seldom seen, these frogs can be easily identified by their characteristic call that carries a considerable distance. The atlas data are reliable and reasonably complete. Gaps in distribution in Mpumalanga and Limpopo provinces do not reflect an absence of the species.

Habitat

This species inhabits a wide variety of bushveld vegetation types, predominantly Mixed and Sweet Lowveld Bushveld, and Coastal Bushveld-Grassland, in the Savanna Biome. The breeding habitat consists of well-vegetated pans, vleis, marshes and dams.

Life history

Outside of the breeding season, during the dry winter months, K. maculata has been found in cavities excavated in the damp mud at the bottom of empty pans (Pienaar et al. 1976), or under moist debris (Loveridge 1953a).

The breeding season usually begins in early November and continues until the end of February, depending on weather conditions (Bishop 1994). During the day, the frogs are rarely seen, remaining well hidden in clumps of dense vegetation (particularly Eleocharis limosa, Cyperus immensus and C. papyrus), and occasionally under logs or in the axils of banana leaves. Choruses develop in the late afternoon or early evening, before dusk. Males move closer to the water where they call from the water, well concealed under overhanging vegetation. Later they may be found calling from elevated positions, up to 50 cm above the water, in clumps of emergent vegetation (Bishop 1994). The males appear to have two distinct calling periods, one in the early evening (16:30–20:00) and another in the early morning, peaking between 02:00 and 03:00 (Bishop 1994).

The eggs are laid singly or in lines of four or five, attached to submerged vegetation. The tadpoles are large and fish-like, similar to, but larger than those of K. senegalensis. They are up to 130 mm long with deep keel-like tails that arise from the top of the head.

K. maculata is a voracious predator of invertebrates and also eats small frogs, such as Hyperolius marmoratus and Afrixalus aureus (Wager 1965; Channing 2001). K. maculata produces a characteristic odour when handled and is quite unpalatable, due to the production of defensive amines and peptides, such as caerulein and kassinin, by glands in the skin (Roseghini et al. 1988). In spite of these defences, there are records of predation on this species by the Yellowbilled Egret Egretta intermedia and the Vine Snake Thelotornis capensis (Channing 2001).

Conservation

K. maculata is locally abundant and occurs in a number of protected areas, including Kruger National Park. However, a major threat to this species is habitat loss through water drainage and afforestation. In several areas in KwaZulu-Natal, exotic Eucalyptus plantations have lowered the water table to such a degree that many pans in the coastal mosaic of forest, thicket and grassland, have completely disappeared. Nevertheless, the species does not appear to require special conservation action at present.

Current distribution map

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