Amphibia , Anura , Leptodactylidae , Leptodactylus furnarius : New country record , geographic distribution map and advertisement call

The Neotropical genus Leptodactylus Fitzinger, 1826, currently includes 81 recognized species, and is widely distributed from southern North America throughout most of South America to central Argentina. It is also present at the Greater and Lesser Antilles (Frost 2007). Four species groups were traditionally considered within this genus: the L. fuscus, L. melanonotus, L. ocellatus, and L. pentadactylus groups (Maxon and Heyer 1988). However, a recent taxonomic revision based on morphological, behavioral, and ecological evidences, presented by Heyer (1998) and Kokubum and Giaretta (2005), placed Lithodytes (including Adenomera) as a subgenus of Leptodactylus on phylogenetic grounds (Frost et al. 2006).

The richest and most widely distributed group, the Leptodactylus fuscus species group, is characterized by laying eggs in foam nests inside terrestrial burrows (Heyer 1969;Prado et al. 2002;Haddad and Prado 2005).A member of this group, Leptodactylus furnarius, is distributed in central, southeastern, and southern Brazil, northeastern Paraguay, and northern Uruguay (Heyer and Heyer 2004;Brusquetti and Lavilla 2006).This frog is characteristic of open formations (IUCN et al. 2006) and typically occurs throughout much of the Cerrado Ecoregion, although its range marginally reaches the Atlantic Forest and hilly environments of northern Uruguay (Heyer and Heyer 2004;Brusquetti and Lavilla 2006).
Herein, we report the first record of L. furnarius in Argentina, provide a geographic distribution map including all known localities for this species, and present an analysis of its advertisement call.Voucher specimens were deposited in the Diego Baldo Collection, housed at Museo de La Plata (MLP-DB 3555, juvenile; MLP-DB 5932-3 and 5935, three adult males; and MLP-DB 5934, one female).The advertisement call of an unvouchered specimen (seen calling but not collected) was recorded with a Sony WM-D6C tape recorder and a Sennheiser LR 6 microphone.This call was compared with previous published calls reported for the species (Sazima and Bokermann 1978;Heyer and Heyer 2004;Kokubum and Giaretta 2004) Specimens of Leptodactylus furnarius from Argentina (Figure 1) were collected during fieldworks carried out in December 2004 and October 2007, at the intersection of the Ruta Nacional Nº 12 and Ruta Provincial Nº 3, Departamento Candelaria, province of Misiones, Argentina (27º27'46'' S, 55º40'55'' W).Individuals were found breeding in hydrophilic grasslands mainly composed by Poaceae (Figure 2).This area is characterized by rush communities and savannas, which alternate with woodlands and forest patches of Astronium balansae (Anacardiaceae) in a smooth hilly landscape (Cabrera 1976;Fontana 1993;Giraudo et al. 2003) named Distrito de los Campos (Giraudo et al. 2003).This biogeographic unit represents a transitional zone between the Atlantic Forest and the Humid Chaco ecoregions (Cabrera 1976;Dinerstein et al. 1995) 2006), and approximately 300 km to the northwest from the closest known locality in Brazil, municipality of Santa Maria, state of Rio Grande do Sul (Heyer and Heyer 2004) (Figure 3).
- -----------The advertisement call of specimens here examined consists of a single and non-pulsed short note regularly repeated (Figure 4).The call exhibits an ascendant modulation frequency distributed between 2700 and 3600 Hz.The acoustic parameters of specimens from Misiones (Argentina) and Rio Claro (Brazil) are very similar to those previously described from the type locality (Sazima and Bokermann 1978), from Mato Grosso (Heyer and Heyer 2004), and also from Minas Gerais (Kokubum and Giaretta 2004) (see Table 1).The dominant frequency is the fundamental one and is slightly higher for specimens from Misiones, Argentina.We did not observe any pulsed notes (Figure 5) like those reported by Heyer and Heyer (2004) for specimens from Mato Grosso, Brazil.These slight differences in note frequency and structure could be explained by inter-individual and/or interpopulational or by differences in the equipment used to record and/or calling analysis programs, for which more data are needed to clarify. ----------------------

Figure 2 .
Figure 2. Habitat of Leptodactylus furnarius in the province of Misiones, Argentina.

Figure 5 .
Figure 5. Oscillogram of one advertisement call (see the non-pulsed structure) of Leptodactylus furnarius, unvouchered specimen; same data as in Figure 4.

Table 1 .
Characteristics of the advertisement call of Leptodactylus furnarius from the Argentinean province of Misiones and the Brazilian states of São Paulo, Mato Grosso, and Minas Gerais.