RESUMEN
Conflicts between rural people and the Endangered Black-and-chestnut Eagle (Spizaetus isidori) are a prominent conservation concern in the northern Andes, as at least 60 eagles were poached between 2000 and 2022 in response to poultry predation. Here, we conducted direct observations to analyze the Black-and-chestnut Eagle diet and evaluated how forest cover affects the feeding habits of the species during nestling-rearing periods in 16 nests located in different human-transformed Andean landscapes of Ecuador and Colombia. We analyzed 853 prey items (46 species) delivered to nestlings. We used Generalized Linear Models to test whether the percent forest cover calculated within varying buffer distances around each nest and linear distances from the nest to the nearest settlement and pasture areas were predictors of diet diversity and biomass contribution of prey. Forest cover was not a factor that affected the consumption of poultry; however, the eagle regularly preyed on chickens (Gallus gallus) (i.e., domestic Galliformes) which were consumed by 15 of the 16 eagle pairs, with biomass contributions (14.57% ± 10.55) representing 0.6-37% of the total prey consumed. The Black-and-chestnut Eagle is an adaptable generalist able to switch from mammalian carnivores to guans (i.e., wild Galliformes) in human-dominated landscapes, and eagles nesting in sites with low forest cover had a less diverse diet than those in areas with more intact forests. Management actions for the conservation of this avian top predator require studies on the eagle's diet in areas where human persecution is suspected or documented, but also maintaining forest cover for the wild prey of the species, development of socio-economic and psychological assessments on the drivers behind human-eagle conflicts, and the strengthening of technical capacities of rural communities, such as appropriate poultry management.
Asunto(s)
Dieta , Águilas , Especies en Peligro de Extinción , Conducta Predatoria , Animales , Conducta Predatoria/fisiología , Águilas/fisiología , Humanos , Ecuador , Colombia , Animales Salvajes , Bosques , Conservación de los Recursos Naturales , Pollos/fisiología , Conducta AlimentariaRESUMEN
Vultures comprise one of the most threatened groups of birds worldwide. With a total population not exceeding 6700 mature individuals, and in rapid decline across its range, the Andean Condor (Vultur gryphus) is listed as a Vulnerable species in the IUCN red list. Local population extinctions and decline are of particular concern in northern South America, where no more than 340 condors may exist at present. Despite this, no quantitative assessments exist in Ecuador, Colombia, and Venezuela regarding the threats affecting Andean Condor populations. To address this, we compiled records of Andean Condors injured, or killed, between 1979 and 2021. We obtained data of 164 condors affected by different causes of injury, of which 83.5% were reported in Ecuador, 15.2% in Colombia, and 1.2% in Venezuela. Of the total number, 84.7% of the injured individuals died. Between 1979 and 2021, in Ecuador, Colombia and Venezuela, at least 103 Andean Condors were presumably poisoned, 22 were shot, and 39 individuals were affected by other causes. The total number of individuals affected by different causes represents between 48% and 72% of the total population estimated in northern South America. Of great concern is the fact that, between 2007 and 2021, poisoning and shooting together caused the loss of 19-31% of the estimated population of condors in Ecuador, and 7-21% of the estimated population in Colombia. Given the important mortality induced by humans, environmental education programs, socio-ecological research, application of environmental laws, and management strategies based on scientific evidence to prevent and mitigate human-wildlife conflicts are urgently required for effective Andean Condor conservation in northern South America.
Asunto(s)
Falconiformes , Humanos , Animales , América del Sur , Colombia , Ecuador/epidemiología , VenezuelaRESUMEN
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.
RESUMEN
The Andean Condor (Vultur gryphus) in Ecuador is classified as Critically Endangered. Before 2015, standardized and systematic estimates of geographic distribution, population size and structure were not available for this species, hampering the assessment of its current status and hindering the design and implementation of effective conservation actions. In this study, we performed the first quantitative assessment of geographic distribution, population size and population viability of Andean Condor in Ecuador. We used a methodological approach that included an ecological niche model to study geographic distribution, a simultaneous survey of 70 roosting sites to estimate population size and a population viability analysis (PVA) for the next 100 years. Geographic distribution in the form of extent of occurrence was 49 725 km2. During a two-day census, 93 Andean Condors were recorded and a population of 94 to 102 individuals was estimated. In this population, adult-to-immature ratio was 1:0.5. In the modeled PVA scenarios, the probability of extinction, mean time to extinction and minimum population size varied from zero to 100%, 63 years and 193 individuals, respectively. Habitat loss is the greatest threat to the conservation of Andean Condor populations in Ecuador. Population size reduction in scenarios that included habitat loss began within the first 15 years of this threat. Population reinforcement had no effects on the recovery of Andean Condor populations given the current status of the species in Ecuador. The population size estimate presented in this study is the lower than those reported previously in other countries where the species occur. The inferences derived from the population viability analysis have implications for Condor management in Ecuador. This study highlights the need to redirect efforts from captive breeding and population reinforcement to habitat conservation.