Ecological niche and occupation by gray fox (Urocyon cinereoargenteus) at Las Barajitas Canyon, Sonora

Abstract

Hutchinson defines ecological niche considering the relevance of the environment in the n-dimensional space, according to the patterns of species presence in it. For Peterson and collaborators, these patterns set the basis for niche modeling, since they directly affect the proportion of sites occupied by species. To determine the ecological variables that would favor the conservation of biodiversity at the landscape level, the ecological niche and site occupation by the gray fox (Urocyon cinereoargenteus) were simulated using photo-trapping monitoring at Las Barajitas Canyon, Sonora, Mexico. The potential habitat of the fox was modeled with the program MaxEnt, and the occupation (ψ) and probability of detection (p) were estimated with the program MARK. Vegetation was sampled using the quadrants and Braun-Blanquet methods to estimate importance values for the main plants for inclusion in the presence-absence models, as well as to know the state of the vegetation, using the species accumulation function. The sampling effort over one-year was 124 days/night-trap, obtaining 575 photographs of the gray fox. The analysis of the activity pattern revealed that the gray fox is a nocturnal-twilight species. The evaluation of the vegetation sampled evidenced the dominance of the Ruellia-Jatropha-Bursera association. The plant species accumulation function showed a positive linear relationship (r² = 0.97). In accordance with the information criteria (AICc), positive correlations were found between the sympatric species cacomixtle and coyote, and seasonality (i.e. spring and autumn), resulting in ψ = 38.5 % and p = 7.7 %. The spatial dynamics of plant communities and the relationships between animal species observed in this study indicate that, Las Barajitas Canyon is a suitable environment for the gray fox, since the Area Under the Curve (AUC) obtained was close to 1 (0.873).