''Breviceps fuscus'', also known as black rain frog, plain rain frog, brown short-headed frog, and Tsitsikama rainfrog, is a species of frogs in the family Brevicipitidae. It is endemic to the southern coast of South Africa.

Description

''Breviceps fuscus'' have a round body with short limbs and toes. Its feet are inward facing which allows the frog to burrow much more effectively . They grow to about in

snout–vent length Snout–vent length (SVL) is a morphometric measurement taken in herpetology from the tip of the snout to the most posterior opening of the cloacal slit (vent)."direct line distance from tip of snout to posterior margin of vent" It is the most c ...

. Skin has no warts, but pronounced widely spaced lumps or small tubercles and pitting are present. Colouration is typically dark brown or nearly black, with a slightly lighter

ventrum The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso ...

and no pigmented patterns. They have a squat body and their legs are rather short, which gives the frog its distinctive appearance. File:Black Rain Frog imported from iNaturalist photo 15409543.jpg, Front view of black rain frog File:Black Rain Frog imported from iNaturalist photo 72292953.jpg, Top view of black rain frog File:Black Rain Frog imported from iNaturalist photo 15409538.jpg, Side view of black rain frog

Distribution and habitat

The species is only found on the southern slopes of the Cape Fold Belt from Swellendam to the Outeniqua Mountains, at elevations of up to over . It is a burrowing species inhabiting

fynbos Fynbos (; meaning fine plants) is a small belt of natural shrubland or heathland vegetation located in the Western Cape and Eastern Cape provinces of South Africa. This area is predominantly coastal and mountainous, with a Mediterranean clim ...

and forest fringes and does not require the presence of open water. They prefer to dwell near dislodged sand piles due to their burrowing behaviour.

Behaviour

''Breviceps fuscus'' is a burrowing frog, and can be found in tunnels up to 150 mm deep or among vegetation up to about 30 cm above the ground, and it generally prefers to avoid water. The frog generally spends most of its time underground as it does not require open water and is primarily

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

. At night the black rain frog emerges from its burrow to scavenge for food and sometimes mate.

Reproduction

Males call from within burrows (sometimes while guarding eggs) and from above-ground vegetation. The call is a short (0.2 s) "chirp", with a dominant frequency of 1.8 kHz. The eggs are laid within burrows with small (15 mm) openings and about 30–40 mm deep. Each nest consists of approximately 42–43 yellow eggs that are 5 mm in diameter inside 8 mm capsules.

Young

Like frogs in the family Brevicipitidae in general, ''Breviceps fuscus'' show direct development (i.e., there is no free-living larval stage). This means that the breviceps fuscus does not have tadpoles and instead has young which emerge from the egg as smaller versions of the adults. These are called froglets.

Survival

''Breviceps fuscus'' has many survival mechanisms to combat predators as unlike other frogs they are not able to jump or swim to evade predators due to their unique body shape, including the ability to burrow up to 20 centimetres deep (8 inches). They have also been observed to puff up their body to make them up to 7 times larger as a defence mechanism. When in danger, they fill up with air to appear bigger in an attempt to ward off predators like bush pigs, birds, and snakes. They are also able to use this ability to jam themselves in their burrows preventing some snakes from pulling them out of the burrow Their distress call is a short high pitched chirp. They also have small lumps all over their body. This is believed to be a mechanism to deter predators as to a predator these lumps appear poisonous although it is not believed that they are poisonous.

Conservation

''Breviceps fuscus'' is a locally abundant species but the exact population is not known. It does not tolerate habitat disturbance, so habitat loss caused by

afforestation Afforestation is the establishment of a forest or stand of trees (forestation) in an area where there was no previous tree cover. Many government and non-governmental organizations directly engage in afforestation programs to create forests a ...

, the spread of alien vegetation, and too frequent fires are threats to it. However, overall, its habitat is well protected and it occurs in several protected areas.

Taxonomy

The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

''fuscus'' refers to the dark colouration of this species as the animal is usually dark brown or black. The black rain frog was first described by John Hewitt, in 1925 after a specimen was collected in Knysna.

Feeding

Like many other frogs the breviceps fucus is an

Insectivore A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant that eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores wer ...

which feeds on small insects, spiders, insect larvae and worms.

Classification

The ''Breviceps fuscus'' was originally classified as a member of the Microhylidae but polygenic research led to the family Brevicipitidae being classified as a family of its own and ''Breviceps fuscus'' was included in it along with the other frogs in its genus.