IntroductionSubsequent to the description of Gastrotheca ruizi

by Duellman and Burrowes (1986), only two authors have discussed this species. In an assessment of the conservation status of the species, Estupiñan (2004) designated it to the Endangered category of the International Conservation of Nature (IUCN, 2010).

Shortly thereafter, Mueses-Cisneros (2005) reported collecting and hearing calling males of the species at several localities in the Valle de Sibundoy. Herein we summarize the known information on distribution, habitat, and abundance of Gastrotheca ruizi and suggest reassessing its conservation status (Fig. 1).

Material and MethodsIn February 1984, one of us (WED) first studied specimens of a species that subsequently was to be named Gastrotheca ruizi in the Instituto de Ciencias Naturales (ICN) in Bogotá. Later in the same month he and Patricia A. Burrowes collected a small series of the frogs that were deposited in the herpetological collection in the Natural History Museum at the University of Kansas (KU) and formally described this new species of marsupial frog. In March 2011 and January 2012, JEP made observations on this frog in the Sibundoy Valley. JEP obtained geographic coordinates

and elevations by using a Garmin GPS 76 Electronic Mapper. Co-ordinates for other localities were obtained from Acme Mapper 2.0 (mapper.acme.com). Conservation categories were determi-ned following the guidelines of the International Union for the Conservation of Nature (IUCN, 2010).

Results

DistributionGastrotheca ruizi is known only from the Sibundoy

Valley in the southern part of the Cordillera Oriental of the Andes in Departamento Putumayo in southern Colombia. The valley floor is at elevations of 2040–2100 m. The valley is a small interruption of the Cordillera Oriental. This valley is about 20 km long from west to east and no more than 10 km wide; thus it has an area of about 200 km2. To the west of the valley is the high Andean range with the Páramo Quilisayaco, that reach 3210 m. To the east of the valley is another Andean ridge at 2810 m, from which the terrain gradually descends into the Amazon lowlands.

The valley is drained by the Río Putumayo and its tributary, the Río San Pedro; the Río Putumayo exits the southeastern corner of the valley to the Amazon drainage system.

At present, Gastrotheca ruizi is known from 15 localities in the valley and also from an elevation of 2319 on the slope at the eastern end of the valley (Fig. 2), and no other Gastrotheca species are known from the valley. East of the Sibundoy Valley, Gastrotheca andaquinensis Ruiz and Hernandez (1976) has been found in cloud forest at an elevation of 1440 m on the Amazonian slopes of the cordillera (specimens deposited at: KU 169418–22). A high ridge with its

Herpetology Notes, volume 5: 193-196 (2012) (published online on 24 May 2012)

Distribution, habitat, and abundance of a Marsupial frog, Gastrotheca ruizi (Anura: Hemiphractidae), in southern Colombia.

José Ernesto Pérez Villota1 and William E. Duellman2*

1 Herpetological research, University of Nariño, Pasto, Colom-bia; e-mail: jeperezv@gmail.com

2 Division of Herpetology, Biodiversity Institute, University of Kansas, 1345 Jayhawk Blvd., Lawrence, Kansas 66045 USA; e-mail: duellman@ku.edu.

* Corresponding author.

Abstract. Gastrotheca ruizi is an anuran species restricted to the Sibundoy Valley in southern Colombia, where it is reasonably abundant in agricultural areas. Its occurrence in anthropogenic habitats and apparent maintenance of a constant population level are significant evidence that the species is not threatened, as previously suggested; therefore, its conservation status should be changed to Last Concern.

Keywords. Gastrotheca ruizi, Hemiphractidae, habitat preference, abundance, conservation status.

José Ernesto Pérez Villota & William E. Duellman 194

Figure 1. Adult female Gastrotheca ruizi with a SVL of 83.5 mm from San Miguel, Municipio San Francisco, Departamento Putumayo, Colombia, January 2012. Photo by José Ernesto Pérez Villota.

Figure 2. Localities of known occurrence of Gastrotheca ruizi in the Sibundoy Valley in southern Colombia.

Distribution, habitat, and abundance of a Marsupial frog, Gastrotheca ruizi 195

upper elevations supporting the Páramo de Quilosayaco separates the Sibundoy Valley from the basin of Lago de la Cocha at an elevations 3700–2900 m; therein is subparamo vegetation inhabited by G. espeletia (Duellman and Hillis, 1987).

HabitatThe Sibundoy Valley is an old agricultural region

that about 200 years ago was probably forested but today is entirely agricultural. Some of the lands are used for pasture for cattle or goats, whereas other areas are cultivated principally for subsistence farming. There are a few small streams that flow into the Río Sibundoy and its tributary, the Río Quichoa. Narrow (< 1 m) irrigation ditches have been dug throughout much of the cultivated area. Small stands of trees exist mostly at the periphery of stream and at the edge of the rivers. These trees (Podocarpus, Weinmania, Quercus, Brunellia, Alnus, Miconia) presumably are remnants of the original forest. Trees cover about 40% of the valley. The irrigation ditches support hedges and other aquatic

plants, such as Totora Grass (Cyperaceae: Scirpus californicus) and White Ginger Lily (Zyngiberyaceae: Hedychium coronarium).

As shown in Table 1, throughout the valley, Gastrotheca ruizi has been recorded from various fragments of riparian vegetation (e.g.: bushes, small trees) along streams and ditches. All of these are in cultivated areas. Males have been heard calling from a cornfield.

AbundanceMueses-Cisneros (2005) surveyed 12 localities in the

Sibundoy Valley and reported an estimated 2280–3600 males calling from ditches between agricultural fields and from riparian fragments along the Río Putumayo. At least 100–150 males were calling from a cornfield in January 2012 (JEP, personal observation). Little information is available about reproduction. A brooding female obtained on 25 February 1984 gave birth to 134 tadpoles on 7 March 1984 (Duellman and Burrowes, 1986). A brooding female was found by JEP in January 2012 (Fig. 1).

Locality Coordinates Elevation Microhabitat Record Reference

San Francisco: San Miguel 1.1640N, 76.8720W 2319 m Corn field Female Herein

Sibundoy: Las Planadas 1.6667N, 76.9166W 2060 m Riparian fragment Audio M-C

Sibundoy: Villanueva 1.1960N, 76.9265W 2090 m Ditches Audio Herein

Sibundoy: Leando Agreda 1.1599N, 76.9333W 2060 m Riparian fragment Audio M-C

Sibundoy: Río Putumayo 1.1833N, 76.9500W 2060 m Riparian fragment ICN 48026 M-C

Colón: Troncal 1.1500N, 76.9500W 2060 m Riparian fragment Audio M-C

Colón: El Carmelo 1.6667N, 76.9500W 2060 m Ditches ICN 48003+ M-C

Colón: Las Palmas 1.1833N, 76.9500W 2060 m Riparian fragment Audio M-C

Colón: San Pedro 1.1833N, 76.9500W 2060 m Riparian fragment Audio M-C

Colón: ITP 1.1833N, 76.9500W 2060 m Riparian fragment Audio M-C

Sibundoy: Sibundoy 1.1833N, 76.9333W 2060 m Ditches ICN 2891+ D&B

Santiago: Río Quichoa 1.1167N, 76.9667W 2040 m Riparian fragment Audio M-C

Santiago: San Agustin 1.1167N, 76.9667W 2060 m Fragment/ditches Audio M-C

Santiago: Vda. Franco Muriel 1.1167N, 76.9667W 2040 m Riparian fragment Audio M-C

Santiago: San Andres 1.1167N, 76.9833W 2100 m Fragment/ditches Audio M-C

Santiago: Santiago 1.1410N, 77.0088W 2250 m Ditches KU 200000+ D&B

Table 1. Localities of known occurrence of Gastrotheca ruizi in the Sibundoy, Valley, Colombia. D&B = Duellman and Burrowes, 1986; M-C = Mueses-Cisneros, 2005. In the locality column, the name of the municipality is followed by the locality.

DiscussionExisting data on habitat and abundance indicate that

Gastrotheca ruizi apparently is thriving in the Sibundoy Valley. There is no evidence for population decline in the species. Certainly more data on reproduction, sex ratios, and survivorship of tadpoles are desirable. Likewise, knowledge of their diurnal retreats and refugia when not breeding is lacking. Ramírez and Rodríguez (2011) recorded tadpoles and females of G. riobambae (Fowler) in farms and agricultural fields and noted that this Andean species is adapted to ditches and riparian forest. However, use of agrochemicals has negatively affected tadpoles in some areas (WED, personal observation). Other Andean species of Gastrotheca seem to have adapted to habitat modification for agricultural purposes. For example, G. argenteovirens (Boettger) in Departamento Cauca, Colombia, and G. peruana (Boulenger) in Región Cajamarca, Peru, inhabit fields planted in potatoes. Farmers uncover the frog while raking their fields; also the frogs seek shelter in the stone fences bordering the fields (WED, personal observation).

Even though Gastrotheca ruizi is known only from the small Sibundoy Valley. It does not seemed to be threatened, and it is obviously capable of living and reproducing in agricultural areas. The species is abundant in the valley and even though it is known from a only a small area, we recommend assigning it to the category of Least Concern. However, changes in agricultural strategies, such as the use of chemical herbicides, might be detrimental to its existence. Also, reduction of forest cover at higher elevations around the valley, are affecting the hydric potential of the Río San Pedro and the Río Putumayo.

Acknowledgments. JEP thanks Andres Villota for his help in the fieldwork. The map was prepared by Charles W. Linkem.

ReferencesDuellman, W. E., Burrowes, P. A. (1986): A new species of mar-

supial frog (Hylidae: Gastrotheca) from the Andes of southern Colombia. Occ. Pap. Mus. Nat. Hist. Univ. Kansas. 120: 1–11.

Duellman, W. E., Hillis, D. M. (1987) Marsupial frogs (Anura: Hylidae: Gastrotheca) of the Ecuadorian Andes: resolution of taxonomic problems and phylogenetic relationships. Herpeto-logica 43:141–173.

Estupiñán, R. A. (2004): Rana Marsupial de Ruiz Gastrotheca ruizi. Pp 278–282 in Rueda-Almonacid J. V., Lynch, J. D., Amézquita, A, (Eds). Libro Rojo de Anfibios de Colombia. Serie Libros Rojos de Especies Amenazadas de Colombia. Conservación Internacional Colombia, Instituto de Ciencias Naturales-Universidad Nacional, Ministerio del Medio Ambi-ente. Bogotá, Colombia.

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Mueses-Cisneros, J. J. (2005). Crítica a la asignación de categoría de amenaza de Gastrotheca ruizi (Amphibia: Anura: Hylidae). Rev. Acad. Colomb. Cienc. 29 (111): 303–308.

Ramírez J., Salomon y Melina L., Rodríguez, B. (2011) Estado poblacional y relaciones ecológicas de Gastrotheca riobambae (Anura: Hemiphractidae) en dos localidades del Volcán Paso-choa, Pichincha – Ecuador. Boletín Técnico. Serie Zoológica 7: 69–97.

Ruíz-Carranza, P. M., Hernández-C. ,J. I. (1976) Gastrotheca andaquiensis, nueva especie de la Cordillera Oriental de Co-lombia (Amphibia, Anura). Caldasia 11:149–158.

José Ernesto Pérez Villota & William E. Duellman 196

Accepted by Angelica Crottini