Painted reed frog
Hyperolius viridiflavus
SUBFAMILY
Hyperoliinae
TAXONOMY
Eucnemis viridiflavus Duméril and Bibron, 1841, Abyssinia; Hyperolius marmoratus Rapp, 1842, Natal; H. marginatus Peters, 1854, Macanga, Mozambique; Rappia tuberculata Mocquard, 1897, Lambarene, Gabon. About 40 subspecies are recognized.
OTHER COMMON NAMES
English: Reed frog, sedge frog.
PHYSICAL CHARACTERISTICS
H. viridiflavus is a characteristic and abundant reed frog on the savanna, and its call—a chorus sounding like small bells or xylophones—is much more tonal than other Hyperolius calls. All members have a blunt snout and much webbing. Males have a very large gular sac; females have a transversal gular fold, a feature which is otherwise rare in the genus. In contrast to this morphological uniformity, the color pattern varies wildly. As a result of this variation, the group is usually subdivided into subspecies. However, the number of subspecies and the boundaries between them are not settled, and it can even be disputed whether the classical subspecies concept is appropriate here. More than 100 names have given to subspecies in this group, and more than 40 are commonly used.
These forms can be regarded as subspecies of one species, H. viridiflavus, but some researchers prefer to split them up into a small number of species belonging to a "superspecies." This is partly because there are a few cases of two "subspecies" occurring together, which indicates that they cannot interbreed and are thus not the same species.
The group is often split into three species: H. viridiflavus, distributed throughout West Africa and the northern part of Eastern Africa to southern Tanzania; H. marginatus, (sometimes called H. parallelus) found from southern Tanzania and northern Mozambique, and across Africa to Angola and the southern Congo; and H. marmoratus, found from the east coast of South Africa to southern Mozambique and Zimbabwe. However, the question of species relationship is far from settled. In addition to the savanna-living members of this group, Hyperolius tuberculatus exist in the forest in central Africa and at a single locality in West Africa. It is usually regarded as a member of the H. viridiflavus superspecies.
DISTRIBUTION
This frog is found throughout the savannas of sub-Saharan Africa.
HABITAT
Most forms are strictly confined to the savanna, but one group (H. tuberculatus) occurs in clearings in the forest belt.
BEHAVIOR
The savanna-living members of the H. viridiflavus group can sit exposed in the glaring sun, even in the dry season. Their skin is almost waterproof thanks to a thin layer of dried mucus, and the young are able to tolerate a water loss of up to one-half their body weight. Some waste products can be stored in the skin as a pigment, so that the skin becomes chalky white in the dry season.
FEEDING ECOLOGY AND DIET
This frog most likely feeds on all suitable arthropods.
REPRODUCTIVE BIOLOGY
Observations in captivity show that members of this group have a great capacity for producing repeated clutches of eggs with intervals of a few weeks, but whether that is also the case in nature is not known. The newly metamorphosed frogs are very large compared to the adult and to other Hyperolius juveniles, and are themselves able to reproduce the following rainy season, perhaps even sometimes late in the same season. At least one observer has noted the ability of this species to change sex from female to male while still maintaining the ability to produce eggs, but this remarkable observation has not been made by the many people keeping this species in terraria.
CONSERVATION STATUS
This species is widespread and common, but some subspecies are very localized.
SIGNIFICANCE TO HUMANS
The Masai in East Africa believe that cattle will die if they eat H. viridiflavus. It may be that the very bright colors of some subspecies are a warning coloration, and their often exposed resting places during the day may enhance the warning effect.
