Integrating Niche Dimensions to Advance the Ecological Study of the Americas' Smallest Cat: The Guigna in Argentine Patagonia.

The guigna has a very restricted geographic range in southern South America, encompassing much of the temperate forests of Chile and Argentina. In the latter country, scientific information about its ecology is anecdotal. We present our findings from the first multi-annual survey of guigna in Argentine Patagonia. We used 35 camera traps in a protected area with over 8000 camera-trap nights, yielding a total of 176 independent events. We investigated habitat use through generalized mixed models and built predictors based on Grinnellian and Eltonian Niche variables. We also investigated the temporal activity patterns between years and temperature-based seasons, comparing also the activity of melanic and spotted individuals. We found that habitat use for guignas was negatively affected by the presence of co-predators and open vegetation; conversely, it was positively affected by the occurrence of thick forests and presence of potential prey. Guignas were mainly nocturnal, despite the relative lack of human impact; in contrast to some prior studies, we found no significant differences in activity of individuals with melanistic and spotted phenotypes. Notably, our study resulted in one of the highest detection rates recorded for the species anywhere, perhaps owing to either a greater availability of natural resources and/or the relative lack of anthropogenic impacts inside the protected area. Whereas the potential for intraguild predation or interference competition may have unsurprisingly had a negative impact on guigna presence, thick forests yielding greater prey availability, perhaps due to greater micro-habitat heterogeneity, appeared to positively influence it. This important study is the first extended research study for the guigna in Argentina; in particular, it is the first to investigate the variables influencing seasonal and annual habitat use and to more extensively investigate diel and seasonal activity patterns, helping to identify crucial scientific limitations that should be further explored in the future.