Atelopus angelito

Coloma, Luis A., Duellman, William E., C, Ana Almendáriz, Ron, Santiago R., Terán-Valdez, Andrea & Guayasamin, Juan M., 2010, Five new (extinct?) species of Atelopus (Anura: Bufonidae) from Andean Colombia, Ecuador, and Peru, Zootaxa 2574, pp. 1-54 : 34-35

Atelopus angelito : New country record for Ecuador

Atelopus angelito Ardila-Robayo and Ruiz-Carranza was named and described from the subparamo of the Páramo de las Papas at Cordillera Central of the Andes in Departamento del Cauca, Colombia, at Municipio de San Sebastián, near Valencia, ca. 1° 51' N, 76° 47' W, 2900–3000 m. Their description was based on five adult males, one female and three juveniles. Additionally, Ardila-Robayo (2005) provided data on conservation. Two other females were recorded (under the name Atelopus sp. 14) from Río La Plata, Comunidad de Morán, Reserva Ecológica El Ángel, Provincia Carchi, Ecuador, by Yánez-Muñoz and Altamirano B. (2005). Herein, these specimens are also referred to Atelopus angelito . They provided SVL’s for two females, a description of color in life, two photographs (top one, KU 178417), and conservation data. Herein we report additional data of the latter individual KU 178417 ( Figs. 4 H, 14), an adult gravid female that we consider to be conspecific with A. angelito . It was found under a stone 14 km (airline) SE Maldonado (ca. 0° 49' N, 78° 3' W, 2500 m), Provincia Carchi, Ecuador, by John D. Lynch, on 31 May 1977. The Ecuadorian localities extend the geographic range of A. angelito 183 km (airline) southwest of its type locality. The color in life of KU 178417 was described by Lynch (field notes, 31 May 1977) as follows: pea green above with black markings; flanks yellow with black, venter orange with black; iris dark brown with yellow edging on pupil. Its measurements and ratios (in mm) are: SVL 49.2, TIBL 17.1, FOOT 19.4, HLSQ 14.1, HDWD 14.3, ITNR 4.6, EYDM 4.5, EYNO 3.5, RDUL 14.0, HAND 11.2, THBL 8.4, SW 16.5, HDWD/SVL 29.1 %, HLSQ/SVL 28.7 %, HLSQ/HDWD 98.6 %, EYNO/EYDM 77.7 %, TIBL/SVL 34.8 %, FOOT/SVL 39.4 %.

A comparison of the female (KU 178417) with specimens of the original description of Atelopus angelito does not reveal any major differences, but there are subtle differences in size, amount of foot webbing, and coloration. The only adult female available from the type locality is smaller (SVL = 41.0 mm) than the Ecuadorian female (SVL = 49.2 mm). Nonetheless, the two additional adult females (deposited at Museo Ecuatoriano de Ciencias Naturales, MECN) recorded from Ecuador by Yanez-Muñoz and Altamirano B. (2005) have SVLs of 41.3 and 43.8 mm. Thus, adult female size of the topotypic female is very close to the range of variation of Ecuadorian females. The extent of webbing described in the diagnosis and depicted (of a male) in Fig. 3 by Ardila-Robayo and Ruiz-Carranza (1998) is greater than that in the Ecuadorian female. However, the amount of webbing in several specimens (including a female) from the type locality depicted in Fig. 4 by Ardila-Robayo and Ruiz-Carranza (1998) is similar to that in the Ecuadorian female. In the types the flanks are black and creamy white, whereas the flanks in Ecuadorian females are black and yellow. These color differences can be attributed to either intraspecific or geographic inter-population variation; however, sample sizes are too small to know with certainty.

Distribution, ecology, and conservation status. Atelopus angelito is known only from paramo and subparamo habitats at elevations of 2500–3000 m on the eastern slopes of Cordillera Central in Departamento del Cauca in southern Colombia to the western slopes of Cordillera Occidental in Provincia Carchi in northern Ecuador. The area of its extent of occurrence is of about 533 km 2. In Ecuador, it occurs in the Bosque de Neblina Montano Natural Formation (according to the classification proposed by Valencia et al. 1999). These localities lie in the high massif of the Nudo de Pasto, as defined by Duellman (1979). At the Ecuadorian locality (14 km SE Maldonado) annual mean rainfall is 1051 mm and the annual mean temperature is 14.2 °C ( Hijmans et al. 2005). The Ecuadorian localities of Atelopus angelito are in close proximity to one locality of A. pastuso at the western versant of Cordillera Occidental ( Fig. 5 ); thus, they might have occurred in parapatry or sympatry at these localities.

Atelopus angelito is considered to be Critically Endangered (Possibly Extinct) (A2ace, IUCN Red List categories and criteria). The species is tagged as Possibly Extinct until further surveys confirm otherwise. The population has declined dramatically (more than 80 %; see below) in the last two decades probably because of climate change and the impact of pathogens, that have affected many other montane species of Atelopus .

The last individual of this species was collected 12 April 1995 in Colombia ( Ardila-Robayo 2005) and there have been no additional efforts to find it. In Ecuador, the last two living individuals were collected on 22 July 1988, and no additional records exist since that date, in spite of seven occasional searching efforts by QCAZ parties (10 June 1989, 2–3 March 1993, 10 May 1996, 23 October 1999, 17 September 2008, 24 September 2008, 28 September 2009) and intensive searching efforts in 2003 and 2004 by MECN parties at seven nearby sites in Provincia Carchi ( Yánez-Muñoz and Altamirano 2005). Presence of the amphibian chytrid fungus was reported in an Ecuadorian locality near the localities for Atelopus angelito and for A. pastuso from 42 km W of Tulcán, Provincia Carchi, in 1993 ( Merino-Viteri 2001).

Figures

FIGURE 3. — Intrapopulation color variation of Atelopus ardila from 12 km E of Pasto, Departamento Nariño, Colombia: (A) KU 169270; (B) KU 169272; (C) KU 169271; (D) KU 169273 (Photos by WED).

FIGURE 4. — (A, B) Atelopus ardila from 12 km E of Pasto, Departamento Nariño, Colombia (KU 169287 – 88, photos: WED); (C – D) Atelopus pastuso from Tulcán and 26, 6 km W Tulcán, Provincia Carchi, Ecuador (MNHG 2258.68, QCAZ 1911, photos: LAC); (E – F) Atelopus pastuso from Tulcán and Cerro Cotacachi (MNHG 2258.65, QCAZ 15021 adult male, photos: LAC, Eugenia M. del Pino, respectively); (G) Atelopus pastuso from Hacienda La Esperanza (EPN 3244 adult female, photo: AA); (H) Atelopus angelito from NE Maldonado (KU 3244 adult female, photo: John D. Lynch).

FIGURE 5. — Map of southern Colombia and northern Ecuador showing localities of Atelopus angelito, A. ardila, A. gigas, A. orcesi, A. pastuso and a population of hypothetical hybrids between A. pastuso and A. ignescens. Symbols for A. ardila indicate one or several close localities.