TAWNY-THROATED LEAFTOSSER SCLERURUS MEXICANUS SCLATER, 1857 (AVES: PASSERIFORMES: FURNARIIDAE: SCLERURINAE) FROM CORDILLERA DE MÉRIDA, ANDEAN VENEZUELA ORELLANA* Andrés; Andrés CHACÓN-ORTIZ*; Zahylis ZAMBRANO○; Nelson SÁNCHEZ◘ & Simón RAMÍREZ◘ aorell@unet.edu.ve; aecortiz@unet.edu.ve, zahylzam@ula.ve, pirrosanchez@hotmail.com *Centro de Estudio de Vectores de Enfermedades, Universidad Nacional Experimental del Táchira, Venezuela. ○ Laboratorio de Sistemas de Información Geográfica. Departamento de Ciencias Sociales. Universidad de los Andes, Táchira, Venezuela. ◘ Gerencia de Gestión Ambiental. Desarrollo Uribante-Caparo, Táchira, Venezuela. ABSTRACT This paper confirms the presence of the Tawny-throated leaftosser (Sclerurus mexicanus Sclater, 1857, Furnariidae) in the Cordillera de Mérida in Andean Venezuela. This is the first vouchered record of this somewhat elusive bird, previously documented by presumed sightings in this area. The patchy distribution across the continent may reflect an artifical distribution from México to South Brazil due to inadequate samping. Key words: Aves. Distribution. Neotropical. Sclerurus mexicanus. Suboscine.Venezuela. RASPA HOJA PECHIRROJIZO SCLERURUS MEXICANUS SCLATER, 1857 (AVES: PASSERIFORMES: FURNARIIDAE: SCLERURINAE) DE LA CORDILLERA DE MÉRIDA, EN LOS ANDES DE VENEZUELA RESUMEN Se confirma la presencia del Raspa hoja pechirrojizo (Sclerurus mexicanus Sclater, 1857, Furnariidae) en la Cordillera de Mérida de los Andes de Venezuela. Es el primer registro documentado por material testigo de este esquivo pájaro previamente documentado por presuntos avistamientos en esta región. La distribución discontinua, que se reporta desde México hasta el sur del Brasil, puede ser el reflejo artifical de las inadecuadas técnicas de recolección que se ha empleado. Palabras clave: Aves. Distribución. Neotrópico. Sclerurus mexicanus. Suboscine. Venezuela. INTRODUCTION Furnariidae is a family of passerine birds native to Central and South America which comprise 236 species (Sibley & Alhquist, 1990; Bernis et al., 2003; Fjeldså et al, 2005). These are generally recognized by their small to medium size, varying degrees of brown, black and rufous coloration; and either soft or somewhat stiff tail reminiscent of the related Dendrocolaptidae. Furnariid skulls are schizorhinal; the syrinx lacking horns on the vocal processes; and the anterior toes free (not united to the full length of the basal phalanges); or the middle and outer toes united having the inner toe free (Vaurie, 1980). In Venezuela, this family is represented by 59 species (Phelps & Meyer de Schauensee, 1979; Hilty, 2003). As a whole, the family is often known as ovenbirds or antbirds, but other common names depict some behavioral and physical attributes, which reflects a wide variety of habits/habitats and body habitus (Fjeldså et al, 2005; Irestedt et al., 2006). Due to their somber coloration and secretive behavior, most species are difficult to observe in the field, in which case, the dark understory and dense vegetation are frequent scenarios while individuals forage for meal. This last is the case for the six species of Sclerurus, and particularly the Twany-throated leaftosser (Sclerurus mexicanus Sclater, 1857), whose distribution is wanting from any of the Andean states that comprises the Cordillera de Mérida in Venezuela, where no definite record exists (Phelps & Meyer de Schauensee, 1979; Vaurie, 1980; Hilty, 2003). Distribution The distribution of S. mexicanus is very patchy and widely interrupted, although it extends extensively from central México to eastern coastal Brazil (Vaurie, 1980). In Venezuela, recorded distribution embraces an isolated nucleus in the Sierra de Perijá in the northwest at Zulia state, and reappears south of the Orinoco in central and southern Amazonas state across Bolívar to northern Guyana (andinus Chapman, 1914). These two geographical clusters are isolated from a larger transandean domain that is apparently continuous from Costa Rica to Bolivia (pullus Bangs, 1902, obscurior Hartert, 1901 and peruvianus Chubb, 1919). One other much smaller patch is found within French Guiana, isolated from the southern banks of the Amazon near its mouth (macconnelli Chubb, 1919); central Mexico to Guatemala and northern Nicaragua (mexicanus), and the eastern Brazilian coast (bahiae Chubb, 1919) (see map 49 in Vaurie, 1980; and p. 499 in Hilty, 2003). Figure 1. Map showing locality of capture (circle) of Sclerurus mexicanus andinus at Siberia Camp, SW Cordillera de Mérida, Táchira state, Venezuela (state boundaries shown). Other localities mentioned in text as observation sites are depicted in numbered squares: 1- La Azulita, 2- Socopó, 3- Barinitas. Case report On November 2, 2008 we had the opportunity to collect a specimen (DESURCA-EB0142) at a cloud forest remnant that straddles a steep ridge that separates the Uribante River drainage to the San Agatón ravine system, which in turn forms the upper Doradas River at its junction with the San Buenas ravine (figure 1). Figure 2. Sclerurus mexicanus andinus in dorsal, lateral and ventral views. DESURCA-EB0142. Scale in centimeters This site is accessible through a dirt road northeast from camp Siberia (1350 masl, 7°53’N – 71°43’W), after passing a short distance (~1.7 Km in line) towards the telecommunication towers. In turn, camp Siberia is located between the localities of La Fundación and Pregonero in Táchira state, at the southwestern slopes of Cordillera de Mérida. The site is recorded as very humid premontane forest acccording to Holdrige’s life zone classification (Ewel & Madriz, 1968). The specimen, of undetermined sex (figure 2), was caught using a 6 meter mistnet placed along forest edge on an open track near a steep slope (1500 m). This individual was found tangled in the lowest section of the net at the break of dawn, slightly past 6 AM. It weighed 24.2 grams and had a total length of 176.0 millimeters. Its left forearm measured 23.0 mm, while its left wing measured 112.0 mm (from armpit to tip of third feather), while wing as measured by Vaurie (1980) is 77.7 mm, which falls within the species’ range (from wrist to tip of feather). No ectoparasites were found. Presumably, other individuals that escaped our unkeen attention were seen very close to the net, frequently hiding under vegetation debris clinging from the road-cut cliff at the forest edge, in which case might have been the site of a nest. DISCUSSION Sclerurus mexicanus was presumably seen in Orinoquian slopes of venezuelan Andes above Barinitas (Boesman, 1998) and Socopó, as well as the western slopes near La Azulita (Beckers, 2005) however since this and the similar and sympatric gray-throated leaftosser (S. albigularis Sclater & Salvin, 1869) may appear overlooked, no definite record for this region can be addressed as neither photograph or museum specimen exist. The vouchered record given herein gives an important range that fills a large gap and is strong evidence that the species extends its distribution in the main Venezuelan Andean system aside Perijá and gives strong support for those records based on observations. The site at Siberia is located at the southwest end (SE slopes) of Cordillera de Mérida; nevertheless, the species’ distribution towards the northeastern extreme (i.e. towards Lara state, its potential extreme limit) in similar habitats still remains to be disclosed. Finally, the presumably patchy referenced range is perhaps only an artifact that results from lack of adecuate sampling, thus we presume that it actually has a continuous distribution. Nevertheless, habitat degradation may in fact introduce small to medium scale range disjunction forming a complex mosaic throughout that may pose a threat to its integrity. ACKNOWLEDGEMENTS Thanks are given to Gerencia de Cuencas DESURCA (San Cristóbal) especially to Arfilio Montilva for logistic support. To José Luís Rodríguez, fom Decanato de Investigación-UNET under project 04-002-2008 for partial funds. To Zenaida (and family, Siberia), Valeria Bellazzini, Marian Chacón, Betsi Silva (UNET, San Cristóbal), Alba Moncada and Taide Mora (UCAT, San Cristóbal) for field assitance. To William Tovar (ULA, Mérida) for reading the mansucript. REFERENCES BERNIS, F., E. DE JUANA; J. DEL HOYO; M. FERNÁNDEZ-CRUZ; X. FERRER; R. SÁEZ-ROYUELA & J. 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