Species-Specific Responses of Carnivores to Human-Induced Landscape Changes in Central Argentina

<div><p>The role that mammalian carnivores play in ecosystems can be deeply altered by human-driven habitat disturbance. While most carnivore species are negatively affected, the impact of habitat changes is expected to depend on their ecological flexibility. We aimed to identify key factors affecting the habitat use by four sympatric carnivore species in landscapes of central Argentina. Camera trapping surveys were carried out at 49 sites from 2011 to 2013. Each site was characterized by 12 habitat attributes, including human disturbance and fragmentation. Four landscape gradients were created from Principal Component Analysis and their influence on species-specific habitat use was studied using Generalized Linear Models. We recorded 74 events of <i>Conepatus chinga</i>, 546 of <i>Pseudalopex gymnocercus</i>, 193 of <i>Leopardus geoffroyi</i> and 45 of <i>Puma concolor</i>. We found that the gradient describing sites away from urban settlements and with low levels of disturbance had the strongest influence. <i>L</i>. <i>geoffroyi</i> was the only species responding significantly to the four gradients and showing a positive response to modified habitats, which could be favored by the low level of persecution by humans. <i>P</i>. <i>concolor</i> made stronger use of most preserved sites with low proportion of cropland, even though the species also used sites with an intermediate level of fragmentation. A more flexible use of space was found for <i>C</i>. <i>chinga</i> and <i>P</i>. <i>gymnocercus</i>. Our results demonstrate that the impact of human activities spans across this guild of carnivores and that species-specific responses appear to be mediated by ecological and behavioral attributes.</p></div

Mean (SD) latency (sec), proportion of choices of the pointed bowl in training sessions, and proportion of choices for G over S in first and second choice tests.

<p>Mean (SD) latency (sec), proportion of choices of the pointed bowl in training sessions, and proportion of choices for G over S in first and second choice tests.</p

Description of the variables used to evaluate the response of four carnivore species to the landscape composition and configuration in the Espinal of the Buenos Aires province, Argentina.

<p>Description of the variables used to evaluate the response of four carnivore species to the landscape composition and configuration in the Espinal of the Buenos Aires province, Argentina.</p

Summary results of information-theoretic model selection and multimodel inference for the relationships between carnivores in the Espinal of Argentina and four gradients reflecting four components extracted from a principal component analysis of landscape variables.

<p>Summary results of information-theoretic model selection and multimodel inference for the relationships between carnivores in the Espinal of Argentina and four gradients reflecting four components extracted from a principal component analysis of landscape variables.</p

Biplots showing the contribution of each variable to each component extracted throughout Principal Component Analysis (CPA) with normalized Kaiser-varimax rotation for each of the buffer sizes constructed around the sites in the Espinal of Argentina where camera trap data were collected.

<p>The upper pair of biplots corresponds to the buffer of 1.5 km, the middle pair corresponds to the buffer of 6 km and the pair below corresponds to the buffer of 6 km. See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0150488#pone.0150488.t001" target="_blank">Table 1</a> for variable description.</p

Summary of the significant responses by four carnivore species in the Espinal of Argentina to the four gradients reflecting four components extracted from a principal component analysis.

<p>For each gradient we report its association (positive or negative) to of the corresponding environmental variables and the type of response shown by each carnivore species (i.e., linear or quadratic; positive or negative).</p

Cross-loading values of the variables for the four principal components (PC) extracted throughout a Principal Component Analysis (CPA) with normalized Kaiser-varimax rotation for each of the buffer sizes constructed around the sites in the Espinal of Argentina where camera trap data were collected.

<p>Cross-loading values of the variables for the four principal components (PC) extracted throughout a Principal Component Analysis (CPA) with normalized Kaiser-varimax rotation for each of the buffer sizes constructed around the sites in the Espinal of Argentina where camera trap data were collected.</p

Results of the multimodel inferences for the relationship between carnivores in the Espinal of Argentina and the gradients reflecting four components extracted from a principal component analysis (see Table 2).

<p>For each carnivore species the estimated values of the parameters of the average model and its 95% confidence interval are shown. GA: “Anthropization Gradient”, GC: “Conservation Gradient”, GF: “Fragmentation Gradient”, GM: “Shrubland Gradient”.</p

Proportion of choices for the generous (G) over the selfish (S) experimenter in the first and second choice tests as a function of group (FD: adult family dogs; SHD: adult shelter dogs; and PUP: puppies).

<p>Proportion of choices for the generous (G) over the selfish (S) experimenter in the first and second choice tests as a function of group (FD: adult family dogs; SHD: adult shelter dogs; and PUP: puppies).</p

Distribution of camera trapping sites and vegetation categories occurring in the study area.

<p>The dark grey area in the map of Argentina represents the Espinal ecoregion.</p