Common Rain Frog

Common rain frog（Image source：Ryanvanhuyssteen， CC BY-SA 4.0 ）

The common rain frog (Breviceps adspersus), also known as the "dumpling frog," belongs to the family Brevicipitidae. It is widely distributed across southern Africa, including Angola, the Democratic Republic of the Congo, Namibia, Botswana, Zambia, Zimbabwe, South Africa, Eswatini, and Mozambique. This species inhabits a wide range of environments, such as dry or temperate savannas, subtropical and tropical dry shrublands, temperate grasslands, as well as agricultural land, plantations, and even suburban gardens. It is highly adaptable and can be found from sea level to montane forests.

The body is round and compact, with short limbs. The hind legs are not adapted for jumping, so it cannot leap or swim like most frogs and instead moves by walking. In water, it maintains buoyancy by inflating its body. Adult size differs between sexes: males measure approximately 3 to 4.7 cm, while females can reach 4 to 6 cm. The dorsal coloration is typically brownish-green to various shades of brown, often with pale yellow or orange bands along the sides of the back. A dark, broad stripe extends from the eye to the forelimb. The ventral side is plain white. Males usually have a dark or mottled throat, while females have a white throat.

This species is fossorial and spends most of its time underground, emerging mainly at night or after rainfall to forage and reproduce. Burrows can reach depths of about 20 cm for dormancy and up to 30 cm for breeding. They dig using their well-developed inner metatarsal tubercle and hind limbs in a backward motion. During dry seasons, they may gather in burrows and enter dormancy, sometimes secreting mucus to form a cocoon that reduces water loss.

In the wild, their diet consists primarily of termites, but they also consume ants and other small invertebrates. Natural predators include jackals, thrushes, and ibises, with ibises even probing into the soil with their long bills to extract them. The breeding season typically coincides with the rainy season. Males call from burrow entrances or the base of vegetation to attract females. Due to their small size and short forelimbs, males cannot grasp females as most frogs do. Instead, both sexes secrete adhesive substances that glue their bodies together, then back into a burrow chamber where eggs are laid. Each clutch contains about 45 eggs. This species lacks a tadpole stage, and the young hatch directly as miniature frogs.

Froglet（Image source：Bernard DUPONT， CC BY-SA 2.0 ）

Housing Requirements in Captivity

Keeping the common rain frog is relatively straightforward, but their fossorial lifestyle and alternating wet-dry habitat must be replicated. A tall enclosure is unnecessary; floor space and substrate depth are more important. A glass tank measuring approximately 45 cm in length and width and about 30 cm in height, or a standard 10-gallon tank, is suitable for housing 3 to 5 individuals.

The substrate should be soft and easily compressible, such as aquarium-grade soil (e.g., Japanese aquasoil), or a mix of coconut fiber and fertilizer-free horticultural humus. The substrate depth should be at least 5 cm, ideally 7 to 8 cm, to allow burrowing. Maintain one half of the enclosure moist and the other half dry so the frogs can choose their preferred humidity. Avoid over-misting the entire enclosure, as excessive moisture can cause mold growth and lead to infections.

Temperature should be maintained between 24 and 29°C, with seasonal adjustments as needed. If ambient temperature is low, a low-wattage heat mat can be applied to the side or bottom of the enclosure, taking care to prevent overheating. Humidity should remain moderate; a rainforest-level humidity is unnecessary, but occasional misting is required during dry conditions. Strong lighting is not needed; a regular day-night light cycle is sufficient.

These frogs tolerate conspecifics well and can be housed together, with little risk of cannibalism. However, ensure that each individual has sufficient space for burrowing and hiding. Provide shelters such as bark, cork bark tubes, or stones.

Feeding Conditions

The common rain frog is an obligate insectivore. In captivity, provide appropriately sized live insects such as small crickets, small roaches, mealworms, ants, or termites. Because of their small mouth and limited ability to capture large prey, the prey size should not exceed half the width of the frog's head.

Juveniles and subadults should be fed daily or every other day, while adults can be fed two to three times per week. It is recommended to vary feeder insects regularly to prevent nutritional imbalance. Before feeding, dust the insects with calcium and multivitamin supplements to prevent metabolic bone disease and vitamin deficiencies.

Place feeder insects in a shallow dish to prevent them from burrowing into the substrate and being wasted. When feeding ants or termites, they can be collected in a small container and then introduced into the enclosure all at once. Never feed wild-caught insects, as they may carry parasites or pesticide residues.

Provide a shallow water dish with water depth just enough to cover the frog's lower body. Use dechlorinated water or bottled water and replace it daily. Although they cannot swim, they absorb water through their skin.

Breeding Conditions

Breeding this species in captivity is relatively challenging, but achievable. The key is to simulate the rainy season by increasing temperature and humidity and maintaining frequent misting over several days. Males call at night from burrow entrances, producing short chirps at approximately 2 kHz, each lasting about 0.1 seconds and often repeated rapidly in groups of three.

During mating, males do not grasp females. Instead, both secrete adhesive mucus that binds them together, and they back into a breeding chamber. The female lays eggs approximately 30 cm underground, with each clutch containing about 20 to 45 eggs. During this period, maintain stable humidity and avoid disturbance. A transparent barrier or small container can be placed over the nesting area to facilitate observation and prevent disturbance by other frogs.

The eggs hatch directly into froglets without a tadpole stage. If successful, juveniles should be housed separately from adults and fed small prey such as fruit flies or tiny crickets. The substrate should remain moist, with adequate hiding spaces.

Preventing Invasive Spread

Keepers must never release these frogs into the wild. If unable to continue care, contact animal shelters, qualified keepers, or zoological institutions rather than abandoning them.

When acquiring individuals, ensure they are legally sourced and captive-bred rather than wild-caught, to prevent overharvesting of native populations in southern Africa. Responsible husbandry and respect for ecosystems ensure that the enjoyment of keeping these animals can coexist with conservation.

Author: Shui-Ye You