Mammalian carnivore occupancy is inversely related to presence of domestic dogs in the high Andes of Ecuador

<div><p>Although the Andes have long been occupied by people, habitat loss, fragmentation through deforestation, and other human activities such as introduction of invasive species have increased drastically during the past century. The Ecuadorian Andes are considered a biodiversity hotspot. However, the fauna and threats to the region are poorly studied, and understanding of factors that shape the distribution of species in habitats disturbed by human activities is needed to identify and mitigate region-wide threats to wildlife. We evaluated factors associated with patterns of occurrence of Andean carnivores in landscapes of the northern Ecuadorian Andes, particularly habitat loss, fragmentation, and occupancy of domestic dogs, and determined whether thresholds occurred for these factors beyond which carnivore occurrence declined markedly. Five study areas (each 20 x 20 km) were surveyed with a total effort of 2,800 camera trap nights. Occupancies of four of the eight carnivores known from the region were best predicted by occupancy of domestic dogs rather than measures of habitat loss and fragmentation [Andean fox (<i>Pseudalopex culpaeus</i>), puma (<i>Puma concolor</i>), striped hog-nosed skunk (<i>Conepatus semistriatus</i>), and Andean bear (<i>Tremarctos ornatus</i>)]. The two largest carnivores, puma and Andean bear, demonstrated significant threshold responses to the presence of domestic dogs at two sites. Four smaller carnivores were recorded too infrequently to model occupancy, and at least two of these species appear to be in decline. The magnitude of domestic dog impacts on native species in tropical areas like the Ecuadorian Andes currently are not recognized. Results of our study indicate that small and large carnivores are in urgent need of conservation and clearly point to dogs as a significant threat to a broad range of native species.</p></div

Estimated β coefficients for the top ranked models of occupancy and mean estimated occupancy (<i>Ψ^</i> ± 95% CI) for Andean carnivores.

<p>DISROA, distance to nearest road; DOG, occupancy rates of domestic dogs.</p

Top three models (occupancy, <i>Ψ</i>; detectability, <i>p</i>) for Andean carnivores.

<p>DISROA, distance to nearest road; DOG, occupancy rates of domestic dogs; PRONH, proportion of native habitat; DISHOU, distance to nearest house; MOON, lunar cycle.</p

Estimated β coefficients for the top ranked models of occupancy and mean estimated occupancy (<i>Ψ^</i> ± 95% CI) for domestic dogs.

<p>DISROA, distance to nearest road; DISHOU, distance to nearest house.</p

Variables for habitat loss and fragmentation and other aspects of human disturbance measured at five sites in the Ecuadorian Andes where occupancy of carnivores was modeled, explanatory set of variables for the models, range of values for variables, scale at which the variables were measured, and source of data.

<p>Asterisks show variables retained for occupancy analyses.</p

Top three models (occupancy, <i>Ψ</i>; detectability, <i>p</i>) for domestic dogs.

<p>DISROA, distance to nearest road; MOON, lunar cycle; LANCOU, land cover; DISHOU, distance to nearest house; NUMPAT, number of patches.</p

Mammalian carnivore occupancy is inversely related to presence of domestic dogs in the high Andes of Ecuador - Fig 1

<p><b>Map of the northern Ecuadorian Andes showing the location of the study areas</b> (a, El Morán; b, Fuya-Fuya; c, Filo Curiquingue; d, San Marcos; and e, Guaytaloma), and protected areas (1, Cotacachi-Cayapas Ecological Reserve; 2, El Ángel Ecological Reserve; 3, Cofán Bermejo Ecological Reserve; 4, Cayambe-Coca National Park; 5, Antisana Ecological Reserve; and 6, Sumaco-Napo-Galeras National Park).</p

Andean Condor (<i>Vultur gryphus</i>) in Ecuador: Geographic Distribution, Population Size and Extinction Risk

<div><p>The Andean Condor (<i>Vultur gryphus</i>) 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.</p></div

Geographic distribution of Andean Condor (<i>Vultur gryphus</i>) in Ecuador.

<p>Blue dots are roosting sites surveyed during September 29–30, 2015. Red polygons represent the National System of Protected Areas. Green areas represent extent of occurrence (left) and area of occupancy (right).</p

Environmental predictors used to model geographic distribution of Andean Condor (<i>Vultur gryphus</i>) in Ecuador.

<p>Environmental predictors used to model geographic distribution of Andean Condor (<i>Vultur gryphus</i>) in Ecuador.</p