Diet, microhabitat and time of activity in a Pristimantis (Anura, Strabomantidae) assemblage

We tested if the richness and abundance of six closely related species of Pristimantis significantly varied among three transects located at different distances from a creek in an Andean cloud forest. We found that richness and abundance of frogs varied significantly among transects, being the transect located at the forest interior the richest in frog species and number of individuals. We chose these more crowded sites to evaluate resource use differences among the species. We evaluated ecological variables such as microhabitat, diet, and time of activity in these species that are similar in morphology and body size, to determine whether they have differences in the use of these resources. Most specimens perch on leaves at heights within 1.5 and 2.0 m of the ground and are nocturnal; only P. douglasi was found with diurnal and nocturnal activity. The species had similar diets, they ingested a wide spectrum of prey sizes that are similar among species, months, and between transects. Almost all collected frogs were juveniles and were found during every single month of sampling suggesting continuous reproduction; however, adults and juveniles of P. douglasi were absent during some of the drier months, indicating seasonality. Thus, we found that most of these Pristimantis species occupy the forest interior and that there is no a strong segregation in the use of the evaluated resources, only one species had a slight difference in activity and reproductive time

Diet, microhabitat and time of activity in a Pristimantis (Anura, Strabomantidae) assemblage

We tested if the richness and abundance of six closely related species of Pristimantis significantly varied among three transects located at different distances from a creek in an Andean cloud forest. We found that richness and abundance of frogs varied significantly among transects, being the transect located at the forest interior the richest in frog species and number of individuals. We chose these more crowded sites to evaluate resource use differences among the species. We evaluated ecological variables such as microhabitat, diet, and time of activity in these species that are similar in morphology and body size, to determine whether they have differences in the use of these resources. Most specimens perch on leaves at heights within 1.5 and 2.0 m of the ground and are nocturnal; only P. douglasi was found with diurnal and nocturnal activity. The species had similar diets, they ingested a wide spectrum of prey sizes that are similar among species, months, and between transects. Almost all collected frogs were juveniles and were found during every single month of sampling suggesting continuous reproduction; however, adults and juveniles of P. douglasi were absent during some of the drier months, indicating seasonality. Thus, we found that most of these Pristimantis species occupy the forest interior and that there is no a strong segregation in the use of the evaluated resources, only one species had a slight difference in activity and reproductive time

Diet, microhabitat use, and thermal preferences of Ptychoglossus bicolor (Squamata: Gymnophthalmidae) in an organic coffee shade plantation in Colombia

Ptychoglossus bicolor is a small gymnophthalmid lizard distributed in the Magdalena Valley of Colombia. We studied ecological features of diet, microhabitat use, and thermal preferences of a population found in an organic coffee shade plantation at the Cordillera Oriental of the Colombian Andes. The studied population had a diet composed predominantly of isopods. The Relative Importance Index of isopods was 98.8%; there were no significant monthly differences in the full stomach content and volume of isopods eaten during the sampling year, neither between rainy and dry seasons. A large number of lizards were found active in the leaf-litter, buried around coffee tree roots, and under or in rotting logs. Lizard body temperature was positively correlated with substrate temperature and air temperature; sex differences in body temperature were not significant. At the studied locality we did not find lizards out of the coffee fields. Our results suggested that these lizards successfully cope with the conditions offered by the organic coffee areas as a result of the cultivation system. Thus, this population might be vulnerable to any modification of the habitat that changes microhabitat availability and abundance of isopods.Ptychoglossus bicolor es un pequeño lagarto de la familia Gymnophthalmidae, que habita el valle del Río Magdalena de Colombia. Se estudiaron las características ecológicas de la dieta, uso de microhábitat y preferencias termales de una población que habita una plantación de café orgánico bajo sombra en la Cordillera Oriental colombiana. La dieta en esta población está dominada por isópodos. El Índice Valor de Importancia Relativa fue del 98.8% y no hubo diferencias mensuales significativas en el contenido estomacal y el volumen de isópodos consumidos durante el año, ni tampoco entre las estaciones de lluvia y seca. Un gran número de lagartos fueron encontrados activos entre la hojarasca, enterrados junto a las raíces de los árboles y bajo o dentro de troncos en descomposición. La temperatura corporal estuvo positivamente correlacionada con las temperaturas del suelo y del aire y no hubo diferencias significativas en temperatura corporal entre los sexos. En esta localidad no encontramos lagartos fuera de los campos de cultivo de café. Nuestros resultados sugieren que estos lagartos sobrellevan exitosamente las condiciones ofrecidas por los cafetales orgánicos como resultado del sistema de cultivo. Así, esta población podría ser vulnerable a cualquier modificación del hábitat que cambie la disponibilidad de microhábitats y la abundancia de isópodos

Role of a campesine reserve zone in the Magdalena Valley (Colombia) in the conservation of endangered tropical rainforests

Tropical forests of Colombia have one of the highest deforestation rates in the world. The humid forest of the Magdalena valley region is one of the ecosystems with the highest risk of landscape transformation, despite being home to many endemic and threatened species. The aim of this study was to evaluate the role of a Peasant Reserve Zone in the conservation of tropical humid forests and endangered species in the Magdalena valley region. To reach this aim, we performed a multi-temporal analysis of the forest dynamics in the Peasant Reserve Zone-Cimitarra River Valley (PRZ-CRV) and assessed the extinction risk of eight species endemic to Colombia. Our outcomes indicated that the most extended land cover in the PRZ-CRV is the forest (56.30%), followed by open areas (38.75%). The forest dynamics analysis indicated that the forest cover has decreased by 3.82% between 2017 and 2019, being the area with redoubts from the Serranía de San Lucas Forest the most conserved. Finally, our results indicated that less than 50% of the climatically suitable areas for each species are covered by forests and that less than 10% of those areas are covered by Protected Areas, while for such species as Agalychnis terranova and Ateles hybridus the PRZ-CRV covered a higher percentage of their distribution than all Protected Areas together in this ecosystem. In conclusion, our results have indicated that the PRZ-CRV could be an important area for the maintenance and conservation of humid forests and their associated fauna, playing an important role as an ally to the Protected Area system in the Magdalena valley region