Forest rain frog, Northern Forest Rain Frog
© 2015 Stuart Nielsen (1 of 0)
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
Life History, Abundance, Activity, and Special Behaviors
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
Possible reasons for amphibian decline
General habitat alteration and loss
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).
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 Nov 19, 2018.
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Citation: AmphibiaWeb. 2018. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 19 Nov 2018.
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