Common name: Red Snouted Treefrog

Synonyms and Other Names: Scinax rubra.

Taxonomy: available through www.itis.gov

Identification: Scinax ruber is a medium-sized hylid (treefrog) with an average SVL (snout-vent length) of 33-39 mm (about 1.25-1.5 in) (Murphy, 1997; Rivero, 1998). The toe pads (disks) are conspicuous, wider than long, and the snout is somewhat pointed, protruding over the mouth (Schwartz and Henderson, 1991; Murphy, 1997). The toes are webbed (Rivero, 1998). There is a transverse fold of skin across the chest (Murphy, 1997). The dorsal color ranges through various shades of yellow, brown, yellow-brown, or greenish-chestnut with two darker brown streaks running posteriorly, and a blotch or triangle between the eyes (Schwartz and Henderson, 1991; Murphy, 1997; Rivero, 1998). A dark streak often runs from the snout posteriorly through and past the eye, sometimes over and further posterior to the tympanum (Murphy, 1997). The upper margin of the iris can be red-gold (Murphy, 1997). The calls of S. ruber are a continuous mechanical, erratic squeaking of up to 10 notes sounding like "aah-aah-aah" occasionally interspersed with a softer, more abbreviated "chuck-chuck-chuck" (Schwartz and Henderson, 1991; Murphy, 1997). The common scinax has been illustrated by Mattison (1987a, b), Murphy (1997), Renjifo [1997], Joglar (1998), and Rivero (1998).

Size: snout vent length of 33-39 mm

Native Range: The indigenous range of S. ruber is from lower Middle America through much of northern South America including Panama, Venezuela, Amazonian Ecuador, Colombia, Amazonian Peru, Amazonian and coastal Brazil, the Guianas, and Trinidad and Tobago (Hoogmoed, 1979; Lynch, 1979; Rivero-Blanco and Dixon, 1979; Frost, 1985; Schwartz and Henderson, 1991; Murphy, 1996, 1997; Renjifo, [1997]; Campbell, 1999; Duellman, 1999a).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology: Scinax ruber is an arboreal hylid that prefers mesic conditions in open lowlands, especially savannas, coastal lowlands, the South American llanos, disturbed and cut-over forests, forest remnants, and anthropogenic habitat such as buildings and agricultural fields (Rivero-Blanco and Dixon, 1979; Schwartz and Henderson, 1991; Murphy, 1997; Duellman, 1999a,b; Hedges, 1999).  They avoid the deep forests (Duellman, 1999b).  The clearing of forests for agriculture and roadways in Amazonian South America creates new habit that is quickly invaded by S. ruber (Duellman, 1999b).  The common scinax is clearly a human commensal that thrives in a wide variety of anthropogenically modified conditions (Murphy, 1997).   The diet of S. ruber is primarily insectivorous (Schwartz and Henderson, 1991).  During rainfall they opportunistically breed in almost any standing, shallow water, preferring to lay their eggs among aquatic vegetation (Crump, 1974; Schwartz and Henderson, 1991; Murphy, 1997).  The number of eggs varies from 68-960 (Crump, 1974; Schwartz and Henderson, 1991).

Means of Introduction: The means of introduction of S. ruber is uncertain, but they may have accidentally been brought to Puerto Rico on imported plants or agricultural products (Rivero, 1998). Since S. ruber is a common stowaway on tropical fruit imports, especially bananas (Mattison, 1987b), perhaps the same is true for frogs introduced to the Lesser Antilles. There also is the possibility of pet releases occurring, since S. ruber is sometimes kept as a pet (Mattison, 1987b).

Status: In Puerto Rico, breeding populations of S. ruber are established and spreading to other parts of the island (Schwartz and Henderson, 1991; Joglar, 1998; Rivero, 1998; Hedges, 1999; Thomas, 1999; Rios-López, 2000).

In the Lesser Antilles, the common scinax is well established on St. Lucia (Frost, 1985; Schwartz and Henderson, 1985, 1991; Censky and Kaiser, 1999; Hedges, 1999), but populations originally identified as S. ruber on St. Maarten/St. Martín are actually misidentified Osteopilus septentrionalis (Powell and Henderson, 2003; see the species account titled "Osteopilus septentrionalis (Duméril and Bibron, 1841)" on this website.).

Impact of Introduction: The impact of breeding populations of nonindigenous S. ruber is unknown, but adults and their aquatic tadpoles could potentially have an ecological effect on small indigenous frogs.

Remarks: The taxonomy of S. ruber has been summarized by several authorities (Frost, 1985; Powell et al., 1996; Murphy, 1997; Crother, 1999). In the past, S. ruber has been variously placed in the genera Hyla and Ololygon (Frost, 1985; Schwartz and Henderson, 1985, 1991; Murphy, 1997; Crother, 1999). Aspects of the natural history of S. ruber have been reviewed by Schwartz and Henderson (1991), Renjifo [1997], and Murphy (1997). Upon placement into the genus Scinax from Ololygon the specific epithet rubra became ruber for gender concordance.

References: (click for full references)

Campbell, J. A. 1999. Distribution patterns of amphibians in Middle America. Pp. 111-210. In: W. E. Duellman (editor). Patterns of Distribution of Amphibians. A Global Perspective. The Johns Hopkins University Press, Baltimore. 633 pp.

Censky, E. J., and H. Kaiser. 1999. The Lesser Antillean fauna. Pp. 181-221. In: B. I. Crother (editor). Caribbean Amphibians and Reptiles. Academic Press, San Diego. 495 pp.

Crother, B. I. 1999. Evolutionary relationships. Pp. 269-334. In: B. I. Crother (editor). Caribbean Amphibians and Reptiles. Academic Press, San Diego. 495 pp.

Crump, M. L. 1974. Reproductive strategies in a tropical anuran community. University of Kansas Museum of Natural History Miscellaneous Publication (61):1-68.

Duellman, W. E. 1999a. Distribution patterns of amphibians in South America. Pp. 255-328. In: W. E. Duellman (editor). Patterns of Distribution of Amphibians. A Global Perspective. The Johns Hopkins University Press, Baltimore. 633 pp.

Duellman, W. E. 1999b. Global distribution of amphibians: Patterns, conservation, and future changes. Pp. 1-30. In: W. E. Duellman (editor). Patterns of Distribution of Amphibians. A Global Perspective. The Johns Hopkins University Press, Baltimore. 633 pp.

Frost, D. R. (editor). 1985. Amphibian Species of the World. A Taxonomic and Geographical Reference. Allen Press, Inc. and The Association of Systematics Collections. Lawrence, Kansas. 732 pp.

Hedges, S. B. 1999. Distribution patterns of amphibians in the West Indies. Pp. 211-254. In: W. E. Duellman (editor). Patterns of Distribution of Amphibians. A Global Perspective. The Johns Hopkins University Press, Baltimore. 633 pp.

Hoogmoed, M. S. 1979. The herpetofauna of the Guianan region. Pp. 241-279. In: W. E. Duellman (editor). The South American herpetofauna: Its origin, evolution, and dispersal. Monograph of the Museum of Natural History, University of Kansas (7):1-485.

Joglar, R. L. 1998. Los Coquíes de Puerto Rico. Su Historia Natural y Conservación. Editorial de las Universidad de Puerto Rico, San Juan. 232 pp.

Lynch, J. D. 1979. The amphibians of the lowland tropical forests. Pp. 189-215. In: W. E. Duellman (editor). The South American herpetofauna: Its origin, evolution, and dispersal. Monograph of the Museum of Natural History, University of Kansas (7):1-485.

Mattison, C. 1987a. Frogs & Toads of the World. Facts on File, Inc, New York. 191 pp.

Mattison, C. 1987b. The Care of Reptiles and Amphibians in Captivity. Revised Edition. Blandford Press, London. 317 pp.

Murphy, J. C. 1996. Crossing Bond's Line: The herpetofaunal exchange between the eastern Caribbean and mainland South America. Pp. 207-216. In: R. Powell and R. W. Henderson (editors). Contributions to West Indian Herpetology. A Tribute to Albert Schwartz. Contributions to Herpetology 12. Society for the Study of Amphibians and Reptiles, Ithaca. 475 pp.

Murphy, J. C. 1997. Amphibians and Reptiles of Trinidad and Tobago. Krieger Publishing Company, Malabar, Florida. 245 pp.

Powell, R., and R. W. Henderson. 2003. A second set of addenda to the checklist of West Indian amphibians and reptiles. Herpetological Review 34(4):341-345.

Powell, R., R. W. Henderson, K. Adler, and H. A. Dundee. 1996. An annotated checklist of West Indian amphibians and reptiles. Pp. 51-91, plates 1-8. In: R. Powell and R. W. Henderson (editors). Contributions to West Indian Herpetology. A Tribute to Albert Schwartz. Contributions to Herpetology 12. Society for the Study of Amphibians and Reptiles, Ithaca. 475 pp.

Renjifo, J. M. [1997]. Ranas y Sapos de Colombia. Editorial Colina, Medellín [and] Santafé de Bogatá. 130 pp.

Rios-López, N. 2000. Geographic distribution: Scinax rubra. Puerto Rico: Toa Baja: Sabana Seca. Herpetological Review 31(1):51.

Rivero, J. A. 1998. Los Anfibios y Reptiles de Puerto Rico. The Amphibians and Reptiles of Puerto Rico. Segunda Edición Revisada. Editorial de la Universidad de Puerto Rico, San Juan. 510 pp. + CD.

Rivero-Blanco, C., and J. R. Dixon. 1979. Origin and distribution of the herpetofauna of the dry lowland regions of northern South America. Pp. 281-307. In: W. E. Duellman (editor). The South American herpetofauna: Its origin, evolution, and dispersal. Monograph of the Museum of Natural History, University of Kansas (7):1-485.

Schwartz, A., and R. W. Henderson. 1985. A Guide to the Identification of the Amphibians and reptiles of the West Indies Exclusive of Hispaniola. Milwaukee Public Museum, Milwaukee. 165 pp.

Schwartz, A., and R. W. Henderson. 1991. Amphibians and Reptiles of the West Indies: Descriptions, Distributions, and Natural History. University of Florida Press, Gainesville. 720 pp.

Thomas, R. 1999. The Puerto Rico area. Pp. 169-179. In: B. I. Crother (editor). Caribbean Amphibians and Reptiles. Academic Press, San Diego. 495 pp.

Other Resources:
Nonindigenous Species Website Links

Global Invasive Species Database Factsheet

Author: Somma, L.A.

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.