Associate Professor University of Minnesota St. Paul, Minnesota, United States
Abstract: The coyote (Canis latrans) has greatly expanded its range in the past century, with expansion southward taking the species to the southern border of Panama and the doorstep of South America. The Darién Gap is a relatively intact swath of rainforest between coyotes and the South American continent. If coyotes disperse through the Darién Gap, they could have diverse effects on South American ecosystems, particularly on the endemic canid assemblage. Of the ten canid species endemic to South America, only two form social groups (Speothos, Cerdocyon) and only one is larger than coyotes (Chrysocyon). The six fox-like species of the genus Lycalopex inhabit open habitats similar in climate to western North America. Given the high levels of intraguild aggression among canid species, the establishment of a novel, relatively large, and more social canid species in South America could have marked effects on endemic canids. Utilizing coyote occurrence data from the GBIF database, we use a MaxEnt niche modeling approach with climatic and forest cover predictors to model the potential overlap of coyotes with native species based on published range extents of those species. We then incorporate forest-cover change to predict the effects of deforestation on habitat suitability for coyotes.
Niche models found 62% of the South American continent to be within the predicted suitable range of the coyote. Rainforest specialists (Speothos, Atelocyon) had little range extent overlap with the model’s prediction for coyotes, while open-habitat specialists (e.g., Chrysocyon, Lycalopex) displayed high overlap. Notably, >90% of the range extent of five Lycalopex species fell within the predicted suitable range for coyotes, including a species that is near threatened and another endangered as classified by the IUCN. Incorporating deforestation 2000–2015 resulted in a nonlinear response in the coyote distribution, with a 3% range extent decrease overall when compared to the model-training data from 2000, while areas with intermediate deforestation saw increased suitability. Coyotes detected in southern Panama in 2016 were approximately 200 km from a near-continuous block of suitable habitat through the Andes to Patagonia and the Cerrado. These findings highlight the importance of tracking the species’ progression southward, monitoring the northern extent of South American canid communities for effects of potential establishment of dispersing coyotes, and limiting deforestation in the Darién Gap to prevent expansion of coyotes southward.
