The Whistling Frog, Leptodactylus fuscus (Family Leptodactylidae)

Rana fusca Schneider, 1799: 130. Syntypes: "Museo Lev. Vincentii", "Museo Lampiano", presumed lost; MNHNP 680 designated neotype by Heyer, 1968, Copeia, 1968: 160–162. Lynch, 1971, Misc. Publ. Mus. Nat. Hist. Univ. Kansas, 53: 186-187, noted that some of the original syntypes (location?) are still extant and without study of these, Heyer's neotype designation should not be accepted. Type locality: Implied to be from Surinam; neotype from "Surinam" (AMNH). Leptodactylus longirostris Garman, 1887b:14 Leptodactylus typhonius — Hart, 1890:25 Leptodactylus sibilatrix — Lynn: 1959:115 Leptodactylus fuscus — Heyer, 1968: 160–162. Common Names: Whistling Frog.
Description Size: Medium sized terrestrial frog to 50 mm SVL. A combination of a light stripe on the posterior surface of the thigh and 6 distinct dorsolateral folds will readily identify this frog. Some specimens also have a light mid-dorsal stripe. It is not sexually dimorphic. Dorsal skin smooth with six or more longitudinal folds or ridges; color pattern highly variable; usually a yellow or red mid-dorsal stripe with rows of spots or dark stripes on either side; background color brown, tan, or red with spots cream, orange, or red. Ventral skin smooth with a discoidal fold, uniformly cream/white. Snout pointed in dorsal view, protruding over mouth in profile. Tympanum distinct, about two-thirds eye diameter. Digits lack webbing and adhesive discs, but toes have a lateral fringe. Vocalization: A loud, repeated short whistle, ‘wheep, wheep’
Distribution and Habitat From Panama throughout South America, east of the Andes, south to southern Brazil, Bolivia, Paraguay, and northern Argentina. It is distributed over much of Trinidad and Tobago. Despite reports from other sources, this frog is not present on the island of Little Tobago.  It occurs from sea level up to 1,700 m ASL. The Whistling Frog is terrestrial and nocturnal, inhabiting savannas, grasslands, marshes, open secondary forests and human-modified environments including open, grassy roadsides. Males call at the onset of rains. Breeding takes place in small burrows in shallow temporary wetlands and the edges of permanent bodies of water or in waterlogged soil. The eggs are deposited in foam nests within a burrow. When the burrows flood the larvae escape into the adjacent wetlands where the tadpoles then develop. Populations. It is common throughout much of its range. In Trinidad and Tobago it is one of the most common anurans.
Taxonomic note This form is a complex of multiple species. Carmago et al. (2006) performed a molecular phylogenetic analysis of specimens collected across the geographic distribution of L. fuscus. The data supported the hypothesis of several cryptic species within L. fuscus. Unlinked mtDNA and nuclear markers supported independently the distinctness of a ‘northern’ phylogenetic unit that included Trinidad and Tobago populations. In addition, the mtDNA data divided the southern populations into two clades that showed no sister relationship to each other, consistent with high differentiation and lack of gene flow among southern populations as suggested by allozyme data. Concordance between mtDNA and allozyme patterns suggests that cryptic speciation has occurred in L. fuscus without morphological or call differentiation.
References Camargo A, De Sa RO, Heyer WR. 2006. Phylogenetic analyses of mtDNA sequences reveal three cryptic lineages in the widespread neotropical frog Leptodactylus fuscus (Schneider, 1799) (Anura, Leptodactylidae). Biological Journal of the Linnean Society 87(2):325-41. Reynolds R, Caramaschi U, Mijares A, Acosta-Galvis A, Heyer RW,  Lavilla E, Hardy J. 2004. Leptodactylus fuscus. In: IUCN 2014