Family Hyperoliidae

Hyperolius argus Peters, 1854

Argus Reed Frog, Argus Sedge Frog, Yellow Spotted Reed Frog, Golden Sedge Frog, Argusrietpadda (A)

By P.J. Bishop

Currently accepted name: Hyperolius argus
Red listing status: Least Concern

Photo by Diedericks G., 2010. URL: FrogMAP: 13

Distribution

H. argus is distributed from the coastal lowlands of southern Somalia, southward through Kenya, Tanzania, Malawi, eastern Zimbabwe and Mozambique (Poynton and Broadley 1987). In the atlas region it is restricted to the coastal plain of KwaZulu-Natal, occurring as far south as Durban (2930DD). Earlier records in southern Africa were incorrectly referred to H. puncticulatus (Poynton 1964; Wager 1965) owing to the close morphological similarity of the two species. However, the species are ecologically separated, with H. puncticulatus occurring only in forest habitat in Malawi and on the coast of Tanzania and Kenya (Poynton 1986; Poynton and Broadley 1987).

The atlas records are reliable but incomplete; more thorough sampling will undoubtedly fill many of the present gaps in the known range of this species.

Habitat

Within the atlas region, this lowland species occurs in Coastal Bushveld-Grassland, a mosaic of vegetation types found from sea level to an altitude of 300 m, along the coast of northern KwaZulu-Natal. It breeds in shallow, often temporary, pans, vleis and marshes, where floating and emergent peripheral plants such as Phragmites spp., Nymphea spp., Cyperus papyrus and Typha latifolia provide call sites for males (Lambiris 1989a; Passmore and Carruthers 1995; Channing 2001; pers. obs.).

Life history

Nothing appears to be known of the non-breeding habits and habitat of this species. Breeding begins after the first rains have fallen in spring, and continues throughout summer. During the day, frogs may be found hiding amongst vegetation at the breeding site, especially in Pistia stratiotes and Nymphea spp., and occasionally under logs or stones in the vicinity. At night, males form fairly large choruses and call from slightly elevated positions on emergent or floating vegetation. Amplexus is axillary, and c.200 eggs are laid in clusters of c.30, attached to submerged or emergent vegetation (Channing 2001; pers. obs.).

Predators include various fish, birds, snakes, terrapins, spiders and other frogs, while prey consists mainly of insects.

Conservation

A major threat to H. argus is habitat loss through urbanization, water drainage and afforestation (Lambiris 1989a; pers. obs.). In several parts of KwaZulu-Natal, plantings of exotic Eucalyptus have lowered the water table to such a degree that many pans within the coastal dune forest have completely disappeared (pers. obs.). At the southernmost limits of the species’ distribution, populations are threatened by rapid urban expansion, resulting in range contractions. An additional threat is the introduction of exotic predatory fish, such as the bass Micropterus salmoides, which are avid predators of both tadpoles and adult frogs.

In areas not affected by human activities, H. argus is locally abundant and populations often consist of hundreds of individuals. The species occurs in several private and provincial nature reserves in KwaZulu-Natal and therefore does not appear to warrant additional conservation action at present.

Current distribution map

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