Project

Taxonomy, natural history and conservation of Glass Frogs (Anura: Centrolenidae )

Goal: To increase knowledge on the diversity and ecology of frogs of the family Centrolenidae.
To advance the science and practice of conserving the frogs of the family Centrolenidae and its ecosystems.

Date: 15 May 2002 - 31 December 2021

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Project log

H. Mauricio Ortega-Andrade
added a research item
We report the rediscovery of Laura’s Glassfrog, Nymphargus laurae Cisneros-Heredia & McDiarmid, 2007, based on two specimens collected at the Colonso-Chalupas Biological Reserve, province of Napo, Ecuador. The species was described and known from a single male specimen collected in 1955 at Loreto, north-eastern Andean foothills of Ecuador. Limited information was available about the colouration, systematics, ecology, and biogeography of N. laurae . We provide new data on the external morphology, colouration, distribution and comment on its conservation status and extinction risk. We discuss the phylogenetic relationships of N. laurae , which forms a clade together with N. siren and N. humboldti . The importance of research in unexplored areas must be a national priority to document the biodiversity associated, especially in protected areas.
H. Mauricio Ortega-Andrade
added 2 research items
En la actualidad, existe cada vez un mayor interés por conocer y aplicar modelos de nichos ecológicos para la solución de diversos problemas biológicos, lo que ha resultado en un incremento en el número de estudios que aplican este enfoque. Sin embargo, a la par también están sucediéndose avances teóricos y metodológicos vertiginosos en este campo, pero que con frecuencia no son considerados, ya que desgraciadamente se mantiene la idea errónea de pensar que los modelos de nichos ecológicos son “recetas” a seguir. Por ello, en este capítulo se presenta una serie de recomendaciones básicas para que sirvan de guía a lo largo de todo el proceso de modelado, así como discutir, en ocasiones, sus potenciales limitantes. Este capítulo está dividido en secciones que pretenden abarcar, en lo posible, algunos de los principales aspectos dentro del campo, como son los conceptos de nicho ecológico y área de distribución, la dualidad de Hutchinson, las diferencias y la reconstrucción per se de los nichos ecológicos y las distribuciones geográficas (que incluye el reconocimiento de las unidades de modelado, la importancia de los datos biológicos –presencias y ausencias– y las variables ambientales a utilizar), el diagrama BAM, el establecimiento del área de accesibilidad (M), algunos tipos de algoritmos y métodos de evaluación, las implicaciones en las transferencias espacio-temporales, así como algunas aplicaciones generales y perspectivas finales del modelado. Sin embargo, como dice el título del capítulo, este es sólo un breve resumen que está muy lejos de ser literatura especializada. Por ello, se recomienda la consulta de una serie de fuentes de información, tanto literatura general como especializada, así como el uso de material en línea y enlistado al final del capítulo, para profundizar en cada uno de los aspectos necesarios para la aplicación de buenas prácticas dentro del modelado de nichos ecológicos.
H. Mauricio Ortega-Andrade
added 2 research items
We describe a new species of Glassfrog of the family Centrolenidae. This new taxon, Terarohyla sornozai sp. nov., is diagnosed by having a protruding snout in lateral profile, uniform green dorsal colouration in life, concealed prepollex, extensive webbing between the outer fingers, fully webbed toes, and small body size. It inhabits the Non-Seasonal Evergreen Foothill and Lowland forests in the provinces of Esmeraldas, Imbabura, and Pichincha, north-western Ecuador.
Amphibians are one of the most threatened animal groups. In the Family Centrolenidae c. 50% of the species are declining and threatened with extinction. One of these is the glassfrog Cochranella mache, endemic to seasonal evergreen forests of the West Ecuadorian region and restricted to highly fragmented forest of < 100 km2 in the Cordillera Mache-Chindul, north-western coastal Ecuador, at 100–640 m. We surveyed this region to elucidate the distribution and conservation status of C. mache. We located it in three new localities and also found a museum specimen from a further new locality. We recommend that the species should be categorized as Critically Endangered because of the continuous and progressive destruction of its increasingly fragmented habitat. Recent surveys of glassfrog species sympatric with C. mache showed low relative abundances compared to surveys in the 1970s and 1980s. Because of the relationship between forest and local climate we suggest that gradual declines of lowland glassfrog populations may be caused by local climate changes produced by forest destruction. In situ conservation is required to halt and mitigate these impacts. Further research on the effects of habitat loss, fragmentation, and associated climate changes on Neotropical amphibians is required.
H. Mauricio Ortega-Andrade
added a research item
Teratohyla sornozai fue recientemente descrita [1] sobre la base de especímenes colectados en tres localidades en las provincias de Esmeraldas, Imbabura y Pichincha, noroccidente del Ecuador. En la descripción original [1], T sornozai se diferenció de Rulyrana orejuela [2] por la forma del hocico (proyectado de perfil en T sornozai, truncado de perfil en R. orejuela), la extensión de la membrana en manos y pies (mayor en T. sornozai), la presencia de melanóforos en las manos y pies (mayor en R. orejuela), el color del iris (gris oscuro con un anillo circumpupilar amarillo en R. orejuela, vs. dorado con reticulaciones oscuras en T. sornozai), y el tamaño corporal (mayor en R. orejuela). Sin embargo, la adquisición de mayor material de R. orejuela y la re-evaluación de los especímenes asignados a T. sornozai permitieron determinar que ambos nombres corresponden a una misma especie. Las diferencias observadas en los especímenes asignados a Teratohyla sornozai se deben a variación intraespecífica (por ejemplo, el color del iris) o a cambios ontogénicos (los juveniles de R. orejuela presentan menos melanóforos en las patas, una mayor extensión en las membranas manuales y pediales). La variación en la forma del hocico parece corresponder a un patrón común observado en varias especies de Centrolenidae, donde los juveniles tienen el hocico proyectado en vista lateral o de perfil. Basados en esta nueva evidencia, colocamos a Teratohyla sornozai Cisneros-Heredia, Yánez-Muñoz y Ortega-Andrade como un sinónimo junior de Rulyrana orejuela Duellman y Burrowes (Figuras 1-2). Con este cambio, el número de localidades conocidas para Rulyrana orejuela en Ecuador se incrementa a cuatro: Mashpi, Saguangal [3], Río Naranjal y Canadé [1].
Diego F. Cisneros-Heredia
added a research item
We describe a new glassfrog from Río Manduriacu Reserve, Imbabura Province, on the Pacific slopes of the Ecuadorian Andes. The new species can be distinguished from most other glassfrogs by having numerous yellow spots on the dorsum and lacking membranes among fingers. Both morphological and molecular data support the placement of the species in the genus Nymphargus. We present a new mitochondrial phylogeny of Nymphargus and discuss the speciation patterns of this genus; most importantly, recent speciation events seem to result from the effect of the linearity of the Andes. Finally, although the new species occurs within a private reserve, it is seriously endangered by mining activities; thus, following IUCN criteria, we consider the new species as Critically Endangered.
Diego F. Cisneros-Heredia
added a research item
Hyalinobatrachium is a behaviorally and morphologically conserved genus of Neotropical anurans, with several pending taxonomic problems. Using morphology, vocalizations, and DNA, a new species from the Amazonian lowlands of Ecuador is described and illustrated. The new species, Hyalinobatrachium yaku sp. n., is differentiated from all other congenerics by having small, middorsal, dark green spots on the head and dorsum, a transparent pericardium, and a tonal call that lasts 0.27–0.4 s, with a dominant frequency of 5219.3–5329.6 Hz. Also, a mitochondrial phylogeny for the genus is presented that contains the new species, which is inferred as sister to H. pellucidum. Conservation threats to H. yaku sp. n. include habitat destruction and/or pollution mainly because of oil and mining activities.
H. Mauricio Ortega-Andrade
added a research item
We studied a population of the endangered glassfrog, Cochranella mache, at Bilsa Biological Station, northwestern Ecuador, from 2008 and 2009. We present information on annual abundance patterns, behavioral ecology, habitat use and a species distribution model performed with MaxEnt. We evaluate the importance of the National System of Protected Areas (SNAP) in Colombia and Ecuador, under scenarios of climate change and habitat loss. We predicted a restricted environmental suitability area from 48,509 Km(2) to 65,147 Km(2) along western Ecuador and adjacent Colombia; ∼8% of the potential distribution occurs within SNAP. We examined four aspects of C. mache ecology: (1) ecological data suggests a strong correlation between relative abundance and rainfall, with a high probability to observe frogs through rainy months (February-May); (2) habitat use and the species distribution model suggest that this canopy dweller is restricted to small streams and rivulets in primary and old secondary forest in evergreen lowland and piedmont forest of western Ecuador, with predictions of suitability areas in adjacent southern Colombia; (3) the SNAP of Colombia and Ecuador harbor a minimum portion of the predicted model of distribution (<10%); and (4) synergetic effects of habitat loss and climate change reduces in about 95% the suitability areas for this endangered frog along its distributional range in Protected Areas. The resulting model allows the recognition of areas to undertake conservation efforts and plan future field surveys, as well as forecasting regions with high probability of C. mache occurrence in western Ecuador and southern Colombia. Further research is required to assess population tendencies, habitat fragmentation and target survey zones to accelerate the discovery of unknown populations in unexplored areas with high probability of suitability. We recommend that Cochranella mache must be re-categorized as "Critically Endangered" species in national and global status, according with criteria and sub-criteria A4, B1ab(i,ii,iii,iv),E.
Diego F. Cisneros-Heredia
added a project goal
To increase knowledge on the diversity and ecology of frogs of the family Centrolenidae.
To advance the science and practice of conserving the frogs of the family Centrolenidae and its ecosystems.