LB 5-45 - The role of landscape heterogeneity and structure in space use of a wide-ranging large carnivore

Background/Question/Methods:

Carnivores use different strategies to hunt prey, with most felids characterized as ambush hunters that are likely to demonstrate spatially consistent predation patterns linked to landscape features. Traditional resource selection studies offer a comprehensive understanding of carnivore habitat selection, but lack insights on patterns and drivers of the spatial distribution of key behaviors - information that may have important ecological implications. Recent research hypothesizes that landscape heterogeneity may drive predator and prey behavior, potentially creating positive feedback loops that drive further heterogeneity, especially in ecosystems dominated by mesoherbivores and lacking megafauna. We aim to understand how landscape heterogeneity impacts space use by a highly adaptive felid, the puma, across three sites in the Patagonian steppe and the high Andes. We used a random forest model to predict puma predation sites based on GPS locations from collared pumas and field investigations of a subset of puma clusters. We then compared the spatial distribution (i.e. degree of clustering) of predicted predation sites with all locations used by pumas. Finally, we used robust regression models to assess how the distribution of (1) all used locations and (2) predicted predation sites each changed with variability in landscape parameters and mean productivity.

Results/Conclusions:

Landscape heterogeneity affected puma space use differently across our study sites, but in line with our expectations, pumas used limited areas within their home ranges for both predation and other activities. In central Patagonia, increasing variability in slope constrained overall puma space use, whereas variation in slope, mean productivity and terrain ruggedness affected the spatial distribution of kill sites within the home range. The site in the high Andes had the highest variability in vegetation and elevation along with the highest levels of terrain ruggedness and primary productivity; pumas in the area moved significantly shorter distances and had highly clumped locations, with mean productivity and terrain ruggedness significantly limiting puma space use. In the Patagonian site on the Atlantic coast, mean productivity constrained overall puma space use, but did not significantly affect kill site distribution. Our analysis suggests that the impact of landscape complexity and variability on puma space use is highly contextual, and although typically understood as the archetypical ambush hunter, the puma is a versatile predator that adopts highly flexible predation and behavioral strategies.