AMPHIBIAWEB
Breviceps sylvestris
Forest rain frog, Northern Forest Rain Frog
family: Brevicipitidae

© 2015 Stuart Nielsen (1 of 1)
Conservation Status (definitions)
IUCN (Red List) Status Endangered (EN)
CITES No CITES Listing
Other International Status None
National Status None
Regional Status None

 

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Description
Breviceps sylvestris is a robust bodied frog with the male holotype measuring 41.7 mm and a female paratype measuring 44.0 mm. The moderately large head is smaller than the body and has a short rounded snout. The snout length tends to be roughly the same in both sexes, at 5.0 mm, is almost vertical, and does not extend beyond the lower lip (FitzSimons 1930). The mouth is down-turned, making the face appear “clown-like” (Minter 2004). The eyes are small and face forward. The distance between the eyes is longer than the width of the upper eyelid. The tympanum is indistinct. The robust body has rough and granular skin that is denser at the mid-line. There are dorsal ridges that are unique to the species, present in both adults and juveniles, and positioned on either side of mid-line, running approximately parallel to each other starting just behind the eye to the middle of the back. Transverse folds are found on the skin of the belly. The limbs are short and robust with digits that are slender and lack circum-marginal disks or webbing. The palms are densely covered in small, round, smooth tubercles. The soles of the feet are also covered in small, round tubercles and also have irregular folds. There is a large, flattened, oval inner metatarsal tubercle that has a long blunt digging edge positioned at a 50 degree axis from the longest toe. The outer metatarsal tubercle is distinct from the inner by being large, sub-circular, and pad-like. At the base of all the digits there are large, semi-divided sub-conical or rounded tubercles (FitzSimons 1930).

Juvenile B. sylvestris have a snout-vent range of about 8.2 mm. Doral ridges are still discernible even when juveniles still have some tail (FitzSimons 1930).

The species is similar to B. gibbosus and B. fuscus, which also has a small eyes and short snout. B. sylvestris can be distinguished from other similar species by its bulky build, large inter-orbital width, and unique dorsal ridges (FitzSimons 1930).

In preservative, the species is a dark brown with irregular yellowish-white spots present on its back with the area between the ridges outlined with a slightly darker outline. The flanks have slightly larger spots. The upper chest and submental regions are a uniform brown while the belly is light brown with squiggly, argus brown lines. A dark band runs from below and behind the eye to the patterning on the chest. (FitzSimons 1930).

In preservative, juveniles are brownish black above and white below. If the tail is still present it is transparent (FitzSimons 1930).

Females are lighter in color and longer than males. Their arms, legs, and feet are longer as well (FitzSimons 1930).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: South Africa

 

View distribution map using BerkeleyMapper.
Breviceps sylvestris is found in Limpopo Province in the north-eastern area of South Africa in forested mountainous areas above 1200m. The species consists of two subspecies inhabiting montane forests and mountain grasslands (Harrison et al. 2001). Breviceps s. sylvestris is found on the eastern escarpment. Brevicep s. taeniatus, found in the Soutpansberg mountains, is separated by unsuitable habitat. The total area that these two subspecies are found is only about 101 km2 at an elevation of 800 - 1800 m above sea level (IUCN 2010).

Life History, Abundance, Activity, and Special Behaviors
The species lives a terrestrial lifestyle in mist-belt forests and grasslands. They have also been found in gardens and on the roadside (IUCN 2016). This habitat is always moist and toads were active after heavy rains during the summer (FitzSimons 1930).

Males call at night during the rainy season on elevated platforms and during the day from the cover of leaf litter. The advertisement call consisting of a series of long, evenly spaced, pulsed whistles, averaging 0.40 s in duration, at an average frequency of 1599 Hz, with an average of 37 pulses at an average rate of 92 pulse per second. The bout duration averages 14 seconds and consists of an average of 14 calls at an average interval of 0.911 seconds, and an average rate of 68 calls per minute (Minter 1999).

Breeding takes place during the rainy season from September to early December. Choruses gather and pairs are formed through adhesive amplexus. Egg masses are laid in nests underground, at the base of rocks or logs, or in the network of tree roots. There is evidence of female parental care as one researcher found a mass of 56 eggs covered with a layer of infertile eggs in a chamber with a female in the adjoining tunnel. The female stayed with the eggs, removing soil that fell on them until they were fully developed. The offspring have direct development (Minter et al. 2004). Breviceps sylvestris develops a network of shallow and horizontal tunnels below the soil for dry winter months, aestivation is speculated but not confirmed (Minter et al. 2004). Juveniles were found in small chambers in the ground below logs (FitzSimons 1930).

Trends and Threats
The population has been decreasing as a result of habitat alteration like deforestation, fire, agriculture, and sometimes housing. Breviceps sylvestris has seen a decrease in area of its habitat by >20% (Harrison et al. 2001). However, B. sylvestris appears tolerance to habitat change. The species also occurs in several protected areas, including Blouberg Nature Reserve, Thabina Nature Reserve, and the Wolkberg Wilderness Area. Breviceps sylvestris was classified as an “Endangered” species in 2010 but was moved to “Near Threatened” in 2016 due to being considered locally a relatively common species and its tolerance to habitat changes (IUCN 2016).

Possible reasons for amphibian decline

General habitat alteration and loss
Intensified agriculture or grazing
Urbanization
Habitat fragmentation

Comments
The species authority is: FitzSimons, V. (1930). “Descriptions of New South African Reptilia and Batrachia, with Distribution Records of Allied Species in the Transvaal Museum Collection.” Annals of the Transvaal Museum, 14, 20-48.

Breviceps sylvestris is part of the Brevicipitidae family in the Anura order. It has two subspecies, B. sylvestris sylvestris and B. sylvestris taeniatus (IUCN 2016). The genus name of this species comes from the latin roots brevi- for short and -ceps for head, describing the group’s characteristically short heads. The species epithet is broken down to sylv- for wood or forest and -estris for belonging or living, describing how it is found in wooded areas (Jaeger 1983).

In 2013, a study was conducted looking at how Batrachochytrium dendrobatidis (Bd) was distributed in threatened South African frog species. Breviceps sylvestris and two other tested species in the genus Breviceps, B. gibbosus and B. macrops, were determined to be uninfected. This comes as a result of their terrestrial lifestyles as Bd infection is enhanced through aquatic environments (Tarrant et al. 2013).

Breviceps sylvestris and B. adspersus have ranges that overlap (Minter et al. 2004).

References

FitzSimons, V. (1930). ''Descriptions of New South African Reptilia and Batrachia, with Distribution Records of Allied Species in the Transvaal Museum Collection.'' Annals of the Transvaal Museum, 14, 20 - 48.

Harrison, J. A., Burger, M., Minter, L. R., De Villiers, A. L., Baard, E. H. W., Scott, E., Bishop, P. J., and Ellis, S. (2001). Conservation Assessment and Management Plan for Southern African Frogs. Final Report. IUCN/SSC Conservation Breeding Specialist Group, Apple Valley, MN.

IUCN SSC Amphibian Specialist Group & South African Frog Re-assessment Group (SA-FRoG). 2016. Breviceps sylvestris. The IUCN Red List of Threatened Species 2016: e.T57721A77162960. http://dx.doi.org/10.2305/IUCN.UK.2016-3.RLTS.T57721A77162960.en. Downloaded on 19 February 2017.

Minter, L. R. (1999). ''Aspects of the Reproductive Biology of Breviceps.'' Thesis, University of the Witwatersrand, Johannesburg

Minter, L.R., Burger, M., Harrison, J.A., Braack, H.H., Bishop, P.J., and Kloepfer, D. (eds.) (2004). Atlas and Red Data Book of the Frogs of South Africa, Lesotho and Swaziland. Volume 9 SI/MAB Series. Smithsonian, Washington D.C..

Tarrant J., Cilliers D., du Preez L. H., Weldon C. (2013). ''Spatial Assessment of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) in South Africa Confirms Endemic and Widespread Infectio.'' PLoS One, 8(7), e69591.



Written by Kaley Jenkins, Yao Saephan, Jeremiah Shon (kajenkins AT ucdavis.edu, ylsaephan AT ucdavis.edu, jjshon AT ucdavis.edu), University of California Davis
First submitted 2017-07-29
Edited by Ann T. Chang (2017-07-29)

Species Account Citation: AmphibiaWeb 2017 Breviceps sylvestris: Forest rain frog <http://amphibiaweb.org/species/2382> University of California, Berkeley, CA, USA. Accessed Oct 22, 2017.



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Citation: AmphibiaWeb. 2017. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 22 Oct 2017.

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