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Distribution and Ecology of the Western Ecuador Frog Leptodactylus labrosus (Amphibia: Anura: Leptodactylidae)

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Leptodactylus labrosus is a terrestrial sit-and-wait predator; its diet includes ground-level, fossorial, and flying insects, and ants numerically predominate. Bothrops asper is recorded as a predator of L. labrosus. L. labrosus lives mainly in deciduous and semi-deciduous forests, where it is restricted to wet microhabitats, and occasionally in evergreen forests. L. labrosus inhabits northern, central, and southern regions of western coastal Ecuador and northern and central western coastal Peru up to 700 m, and into the dry interandean valleys of southern Ecuador and northern Peru up to 1 300 m. Its distribution encompasses moistly seasonally dry forest in coastal Ecuador and Peru. It also occupies moister areas towards the slopes of the Andes where it is sympatric with three other congeneric species, but at sites of sympatry the species show habitat segregation. The distribution pattern of L. labrosus is shared by several other range-restricted amphibians corresponding to the Tumbesian region, which should be recognized as an endemic Amphibian area. The zone between the Choco and Tumbesian regions, where L. labrosus gets in sympatry with other Leptodactylus species, possess ecological and climatic characteristics that have shaped a unique fauna, including several endemic taxa; and it should be recognized as the west Ecuadorian endemic region.
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... Previously conceived just as a transition zone between the Chocoan and Tumbesian regions, recent studies have revealed that several unique, endemic, and highly endangered species are restricted to this region. As such, it has been recognized, for biogeographic and conservation reasons, as an independent Endemic Area (Cisneros-Heredia 2006). ...
... Geographic placement and elevation at collection localities were determined using collector's field notes and museum records, and revised in accordance with the 2000 physical map of the Republic of Ecuador (IGM, 2000), andNGA (2006). Classifications of zoogeographic divisions and vegetation formations from Ecuador follow the proposals by Albuja et al. (1980) and Sierra (1999), as modified by Cisneros-Heredia (2006 Comparisons -Twenty-six described species of Centrolenid frogs share with Cochranella buenaventura the following combination of characters: reduced webbing between fingers, absence of guanophores on the digestive visceral peritonea, and absence of humeral spine. Twenty-three of them differ from C. buenaventura as follows: Cochranella armata has dark dorsal spots and dark spiny nuptial excrescences in adult males. ...
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Cochranella buenaventura sp. nov. is described from the southern foothills of the Cordillera Occidental, Andes of Ec-uador. The new species inhabits the Seasonal Foothill Evergreen forests of the province of El Oro, in the West Ecuadorian biogeo-graphic region. This species is distinguished from other species of glassfrogs by having a truncate snout in dorsal and lateral views, reduced webbing between fingers, absence of guanophores on the digestive visceral peritonea, but present on the renal capsule, absence of humeral spine, green dorsum in life with scattered pale yellow spots, bright yellow hands and feet discs, and moderate body size (20.9-22.4 mm snout-vent length in adult males).
... Little information has been published about the rare Porthidium arcosae Schätti and Kramer, 1993, a small, nocturnal, and terrestrial pitviper (Campbell and Lamar,2004;Valencia et al., 2011). This pitviper is endemic to the Ecuadorian biogeographic province or Tumbesian centre (Cisneros-Heredia, 2006;Morrone, 2014), inhabiting tropical dry forests and scrublands of a small region along the Pacific coasts and lowlands of central Ecuador (Valencia et al., 2011). Only three prey species have been reported so far in the diet of P. arcosae: Microlophus occipitalis Peters, 1871 (Squamata: Tropiduridae), Ameiva septemlineata Duméril, 1851 (Squamata: Teiidae) and Heteromys sp. ...
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Predation on the teiid lizard Dicrodon guttulatum Duméril and Bibron, 1839 by the pitviper Porthidium arcosae Schätti and Kramer, 1993
... Specimens were fixed in 4% formalin and stored in 75% ethanol. We examined specimens (Appendix I Sierra (1999) and the zoogeographic regions and endemic areas follow the definitions by Albuja et al. (1980) with modifications by Cisneros-Heredia (2006. (2) snout truncate in dorsal view, protruding in profile; nostrils slightly elevated producing an slight depression in the internarial area; loreal region concave; (3) tympanic annulus evident, oriented dorsolaterally; very weak supratympanic fold above the tympanum; (4) dorsal skin slightly shagreen with minute granulations; (5) ventral skin coarsely areolate; subcloacal tubercles absent but subcloacal area granular; other cloacal ornamentation absent; (6) parietal peritoneum (condition P3), visceral peritoneum translucent except for pericardium covered by iridophores (condition V1); (7) liver tri-lobed (condition H0); (8) humeral crista dorsalis not forming a humeral spine in adult males; (9) webbing basal between fingers I and II; webbing formula for outer fingers II 1 − -3 III 2 − -1IV (Fig. 2); (10) webbing on feet I 1 − -1 II 1 − -1 − III 1 − -1 − IV 1-1 V (Fig. 2); (11) no dermal folds or tubercles on hands, upper arm or feet; ulnar and tarsal folds present (12) unpigmented nuptial pad Type I; concealed prepollex; (13) first finger longer than second, (14) eye diameter larger than width of disc on finger III; (15) colour in life, uniform bright green dorsum, green bones; (16) colour in preservative, dorsal surfaces deep grey-purple with few blurred cream spots; (17) iris golden copper with dark fine reticulations; (18) melanophores present on fingers and toes; (19) males call from upper side of leaves and ferns around smalls streams; call undescribed; (20,21,22) fighting behaviour, egg clutches, and tadpoles unknown; (23) snout-vent length in adult females 20.4-21.3 ...
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FIGURE 3. (A): Teratohyla amelie; (B): Teratohyla midas; (C): Teratohyla pulverata; (D): Teratohyla spinosa; (E): Teratohyla sornozai sp. nov. Photos by P. Meza-Ramos, A. Georges, M. H. Yánez-Muñoz, R. W. McDiarmid, and H. M. Ortega-Andrade, respectively.
... Está restringida al suelo en microhábitats húmedos, como el margen de riachuelos o pozas. Es más común en bosques secundarios y áreas abiertas muy disturbadas como márgenes de carreteras, potreros y campos agrícolas (Cisneros-Heredia 2006). En la REA es una especie abundante (Fig. 13), ampliamente distribuida, que se encuentra tanto en hábitats perturbados y en bosques. ...
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Arenillas Ecological Reserve (Reserva Ecológica Arenillas - REA) is located in southwestern Ecuador, close to the Peruvian border, and belongs to the Tumbesian Endemism Region and is one of the last remnants of tropical dry forests at altitudes below 100 m a.s.l. Climate is characterized by a rainy season extending from January to May and a dry season extending from June to December. Few studies on the amphibians from the reserve have been made so far. Over a period of twelve months, from 2014 to 2016, we investigated the distribution of amphibians in the REA using regular visual and acoustic survey techniques as well as pitfall traps. Nine species belonging to five families were inventoried, most of them active only during the rainy season. At odds with the usual tropical amphibian communities structure with high species richness but low number of individuals, REA is characterized by a low number of species with a very high number of individuals. Along with species typical for the Tumbesian region, i.e. species specially adapted to dry environments, in the reserve occur also widespread species which are encountered usually in rain forests.
... E cuador is subject to the greatest annual loss of tropical forest in South America (FAO, 2010) and Western Ecuador is greatly threatened by habitat loss and fragmentation (Cisneros-Heredia, 2006). Located within the Tropical Andes Biodiversity hotspot (CEPF, 2014), the Ecuadorean Andes constitute one of the most biologically diverse areas on earth, but are increasingly under threat from agricultural encroachment, road building and timber extraction (Ortega-Andrade et al., 2010). ...
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The cloud-forests of the Western Ecuadorean Andes are highly diverse and under threat from anthropogenic habitat disturbance. Reptiles are sensitive to habitat change and are therefore useful indicators of ecosystem state. Overall diversity has been shown to be highest in old-growth (primary) forest, although older secondary forests can recover to near pre-disturbance levels. We systematically surveyed leaf-litter lizard diversity along a gradient of disturbance in a montane cloud-forest fragment whilst controlling for the potentially confounding effect of elevation. We deployed 21 pitfall trap-lines equally between primary forest, secondary forest of mid-age (18–30 years), and agroforestry, between three altitudinal bands for ten days each over a period of three years. We investigated diversity patterns using Chao 1 and 2 indices (estimated richness), effective species number (ESN), relative abundance of individual species, relative abundance of pooled species, and observed species richness. We also conducted an opportunistic inventory of reptile species. We recorded 7 species of leaf-litter lizards and 15 other species of squamate, the majority of which are rare, recently described and/or of restricted distribution. Elevation was strongly negatively correlated with diversity. Richness and most indices of diversity were higher in primary forest but abundance was similar in primary forest and agroforestry. ESN followed a negative linear response to disturbance but for all other measures agroforestry supported diversity that was either higher than or equal to secondary forest. We conclude that, particularly at high elevations, mid-aged secondary forest is depauperate of leaf-litter lizards but agroforestry potentially supports relatively large populations of generalist species. Lizard diversity in response to human-induced disturbance in Andean Ecuador.
... These forests are cradles of diversity for amphibians and reptiles, showing high species richness and endemism (Duellman, 1979;Hutter et al., 2013;Pincheira-Donoso et al., 2013). Additionally, distributional data and climatic models for some vertebrate groups point to the existence of a transition between northern and central parts of the Chocó bioregion (western Colombia and northwestern Ecuador) and communities found farther south along the Pacific coast and adjacent Andean slopes of Ecuador (Anderson and Jarrín-V, 2002;Anderson and Martínez-Meyer, 2004;Cisneros-Heredia, 2006). The recent description of snake species from the Colombia-Ecuador border (Passos et al., 2009e;Torres-Carvajal et al., 2012) provides support for these observations and demands a greater focus of surveys on these areas. ...
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A new species of Atractus is described from cloud forests of the extreme northern Ecuadorian Andes, Tulcán County, Carchi Province. Atractus savagei sp. nov. is distinguished from all congeners by the combination of 17 dorsal scale rows, long loreal, six supralabials (third and fourth contacting orbit), seven infralabials (first four contacting chinshields), 5–8 maxillary teeth, 161–165 ventrals in females and 149–154 in males, 23–26 subcaudals in females and 28–33 in males, a brown dorsum with black specks on the margins of scales, two black longitudinal stripes on each side of the body, yellow ventral color of head gradually changing to orange and red toward the back of the body, venter with lateral and median series of black blotches arranged in conspicuous longitudinal stripes, moderate body size, a long tail in males, and a moderately bilobed, barely capitate, and slightly calyculate hemipenis. Based on shared morphological characters, especially hemipenial features, we propose to tentatively allocate the new species to the A. paucidens group.
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The Province of Carchi is a strategic area, where the most important remnants of tropical forests of the Ecuadorian Chocó come together. These contact the western foothills of the Andes, between the Mira and San Juan river basins, and ascend to the paramo platforms above 3400 meters in altitude and all the way to 4800 meters. This impressive altitudinal gradient preserves a continuity of ecosystems exposed to great anthropogenic impact, since the area has not been taken into account by the national system of protected areas. However, in these areas the recent rediscovery of endemic and threatened species of amphibians has motivated the Gobierno Autónomo Descentralizado Provincial del Carchi (GADPC) and the Instituto Nacional de Biodiversidad (INABIO), to take up the challenge of compiling 4082 historical information records deposited in 11 collections of natural history in the world, and generated by INABIO in the last three lustrums and in 25 localities of the province. We report that the amphibian richness of the Carchi Province is one of the most representative of the Andes of Ecuador; although it has the third smallest territory among the provinces of the Andean Region, it is the second highest in amphibians (125 taxa) and the first in species density in comparison to the provinces of the Ecuadorian Andes. The outstanding amphibian richness and high percentage of endemism (71%), is a response to the complex eological history of the Andes and the Tropical Forests of the Pacific. These generating isolation barriers, largely influenced by the Mira River watershed that limits the distribution of several lineages of the southwestern Chocó. These barriers translate to changes in the patterns of Alfa-Beta diversity, spatial and temporal distribution and reproductive strategies of the species. The diversity of Carchi amphibians shows a high completeness in phylogenetic and functional structure of its anuran assemblages, contrasting with other Andean areas of Ecuador at similar altitudinal gradients, which have lost several elements in their amphibian communities. Exploration by several institutions in the last five years in the province, have resulted in the discovery of several populations of species considered Extinct (Atelopus longirostris) or Critically Endangered (A. coynei, Centrolene heloderma, Hyloxalus delatorreae), evidencing that its extensive remnants vegetation protect functionally and phylogenetically complete communities. We recorded endemic lineages represented by species restricted to the southwestern Chocó in Colombia and Ecuador, and others exclusive to the Ecuadorean Andes. All the ecosystems in the gradient reach species endemicity between 90% and 100%, per ecological system. Only in tropical lowland ecosystems does the composition of the assembly feed on lineages with widely distributed influences in the Neotropics. Threatened lineages in a synchronous trend with endemic species were present in all ecosystems of the gradient. Between 20% and 50% of species per ecosystem are threatened, with western montane ecosystems tanding out with 45% threatened species in their composition. Weighing the richness of threatened species in the gradient of the province identifies altitudinal bands for all threatened species of amphibians to ecosystems between 2200 and 3000 meters. The exuberant amphibian richness of the Carchi Province requires massive local and national fforts to ensure its persistence over time. The current pressure on the remaining cosystems by mining initiatives in the north of the country will devastate the last populations of critically endangered amphibians, equivalent to one of the greatest phylogenetic losses, the massive decline of amphibians in the 1980s. The conservation of amphibians in the province will guarantee the preservation of functionality and integrity of montane forests. The participation of different public sectors becomes a priority to conserve the varied amphibian diversity of Carchi.
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A checklist of the amphibians and reptiles of 35 localities situated in the northern Peruvian dry forest valley of the Marañón River and its tributaries, containing 14 species of amphibians and 54 species of reptiles, is provided from data collected between July 2005 and April 2014 during several herpetological surveys and from the literature. Detailed accounts are given for each collected species containing morphometric and scalation data, information on natural history, comments regarding their distribution, the conservation status and key literature. Eleven new species were discovered and described during the survey period. At least five additional taxa might also represent new species but more field work and data collection are necessary to determine their status. For two snake species we provide the first country record and for 23 further species new departamental records are provided.
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Whereas previous treatments have considered Heteromys australis the only spiny pocket mouse present in Ecuador, morphological and morphometric analyses of specimens from Ecuador and southwestern Colombia reveal the presence of two species of the genus. Heteromys australis is distributed in evergreen forests from eastern Panamá and western Venezuela through Colombia to extreme northwestern Ecuador, where it inhabits wet, unseasonal areas of the Chocó and adjacent western slopes of the Andes. We here describe a new species, Heteromys teleus, found only in evergreen forests of central-western Ecuador, in areas less mesic and more seasonal than those characteristic of H. australis. Both species possess dark gray dorsal pelage, but H. teleus differs by larger (nonoverlapping) measurements of the hind foot and distinctive cranial proportions. Most notably, the rostrum of the new species is strikingly wide and massive, and the interparietal is narrow and rounded (in contrast to the wide, diamond-shaped interparietal of H. australis). The ranges of the two species together conform to the previously recognized Chocoan evergreen-forest fauna of western Colombia and northwestern Ecuador. However, the restriction of H. teleus to evergreen but seasonal forests of the southern Chocó (transitional between the relatively unseasonal evergreen forests of the central Chocó to the north and highly seasonal xeric regions to the south) is unique within currently recognized species of mammals. Biogeographic overviews hint at similar patterns in other groups, but more alpha-taxonomic research is necessary to evaluate mammalian distributional patterns in the region properly. Most suitable habitat for H. teleus has been converted to agricultural uses, and its current distribution is likely restricted to a handful of small-to-medium-sized forest patches.