Disclaimer:

The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

---

Common name: Rio Grande Chirping Frog

Taxonomy: available through www.itis.gov

Native Range: In the United States, Rio Grande chirping frogs are native to extreme south Texas along the lower Rio Grande Valley in Cameron and Hildago counties (AmphibiaWeb, 2012). The range extends south to the Mexican states of Nuevo León, Tamaulipas, San Luis Potosí, and Veracruz (EOL, 2012).

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

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

Ecology: A terrestrial frog that lays its eggs in moist areas of soil and leaf litter.
Rio Grande chirping frogs inhabit low elevation coastal. Most published accounts of these frogs in the United States (including introduced populations) consist of observations in urban settings. Rio Grande chirping frogs are often associated with debris piles and watered lawns and gardens (Stejneger, 1915; Wright and Wright, 1949; Hayes-Odum, 1990; Brach, 1992). More natural environments include dense vegetation along riparian areas and the edges of lotic, semi-permanent waters (Martin, 1958; Conant and Collins, 1998). Rio Grande chirping frogs can be found under cover objects during the day (Wright and Wright, 1949). Brach (1992) suggests that these semi-tropical frogs are able to persist well north of their native range (e.g., Tyler, Texas) by seeking cover under ornamental rockwork that retains heat and moisture. They are known to utilize arboreal perches 0.2–1.5 m above the ground (Martin, 1958; Hayes-Odum, 1990; Brach, 1992) (AmphibiaWeb, 2012).

Reproduction is terrestrial. Rio Grande chirping frogs do not form breeding aggregations and may maintain territories (Hayes-Odum, 1990). Breeding occurs from April–May, when males may be heard both night and day (Wright and Wright, 1949). Hayes-Odum (1990) found that adults called actively when the relative humidity was above 82% and when air and substrate temperatures were 16–29 °C. In an introduced population in Houston, Texas, males called on rainy nights from April–July (Hayes-Odum, 1990) (AmphibiaWeb, 2012).
Clutches of 5–13 large eggs (3–3.5 mm in diameter) were laid just under the soil surface in the laboratory (Hayes-Odum, 1990) (AmphibiaWeb, 2012). They normally lay eggs in April or May (EOL, 2012). Complete metamorphosis occurs within the egg (known as direct development); young hatch as froglets, ranging in size from approximately 5–8.5 mm (Wright and Wright, 1949; Hayes-Odum, 1990). In a laboratory setting, eggs hatched after 14–16 d of artificial incubation (Hayes-Odum, 1990) (AmphibiaWeb, 2012).

Means of Introduction: May have been introduced to Texas via the plant nursery trade, as in San Antonio and Houston (McGown et al., 1994).

Status: Introduced, and established, in San Antonio, Houston, and Fort Worth, Texas (McGown et al., 1994).

Impact of Introduction: Unknown. The recent introduction of Rio Grande chirping frogs through the potted plant trade into some urban areas (e.g., San Antonio, Texas; Dixon, 2000) may place introduced frogs in direct contact with resident populations of cliff chirping frogs (E. marnockii) and other amphibians. The repercussions of this interaction are unknown, but detrimental effects could include introduction of novel disease pathogens, competition, and/or hybridization. Measures should be instituted to decrease the likelihood of further introductions (AmphibiaWeb, 2012).

Remarks: Scientific and standard English names follow Crother (2008).

References: (click for full references)

AmphibiaWeb: Information on amphibian biology and conservation. [web application]. 2012. Berkeley, California: AmphibiaWeb. Available: http://amphibiaweb.org/. (Accessed: Aug 1-13, 2012).

Brach, V. 1992. Discovery of the Rio Grande chirping frog in Smith County, Texas (Anura: Leptodactylidae). Texas Journal of Science 44:490.

Conant, R. and J.T. Collins. 1998. A Field Guide to Amphibians and Reptiles: Eastern and Central North America. Third edition, expanded. Houghton Mifflin Company, Boston, Massachusetts.

Crother, B.I. (chair). Committee on Standard and English and Scientific Names. 2008. Scientific and standard English names of amphibians and reptiles of North America north of Mexico, with comments regarding confidence in our understanding. Society for the Study of Amphibians and  Reptiles Herpetological Circular. No. 37. iii + 86p.

Dixon, J.R. 2000. Amphibians and Reptiles of Texas, Second Edition. Texas A & M University Press, College Station. 421 pp.

EOL. 2012. " Eleutherodactylus cystignathoides." Encyclopedia of Life, available from http://eol.org/pages/331231/details. Accessed 8 August 2012.

Hardy, L.M. 2004. Genus Syrrhophus (Anura: Leptodactylidae) in Louisiana. Southwestern Naturalist 49:263-266.

Hayes-Odum, L. A. 1990. Observations on reproduction and embryonic development in Syrrhophus cystignathoides campi (Anura: Leptodactylidae). Southwestern Nat., 35:358-361.

Lutterschmidt, W.I. and M.L. Thies. 1999. Geographic distribution: Syrrhophus cystignathoides (Rio Grande chirping frog). Herpetological Review 30:51.

Martin, P. S. 1958. A biogeography of reptiles and amphibians in the Gomez Farias region, Tamaulipas, Mexico. Misc. Publs. Mus. Zool. Univ. Michigan, 101:1-102.

McGown, L. S., M. T. Dixon, and L. K. Ammerman. 1994. Geographic distribution. Syrrhophus cystignathoides. Herpetological Review 25(1):32.

Stejneger, L.H. 1915. A new species of tailless batrachian from North America. Proceedings of the Biological Society of Washington 28:131–132.

Wright, A.H. and A.A. Wright. 1949. Handbook of Frogs and Toads of the United States and Canada. Third edition. Comstock Publishing Associates, Ithaca, New York.

Author: Fuller, P.

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.