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The effects of poaching on wildlife have been widely studied in conservation biology and can be heterogeneous, particularly on ungulates. These effects can be estimated through different methodologies whose use depends on several conditions such as Flight-initiation distance (FID). Our objectives were: 1- to evaluate whether poaching affects the FID and group structure of a guanaco (Lama guanicoe) population in a high cold desert in San Juan (Argentina); 2- to assess whether habitat structure (slope and vegetation cover) influences FID and group structure in this population. The study area included a site with poaching (unprotected area), and a site without poaching (protected area). We recorded 100 groups of guanacos: 70 in the protected and 30 in the unprotected area. FID and group size were greater in the unprotected than in the protected area, whereas proportions of group categories (with offspring, without offspring and solitary) were similar between areas. Besides, in relation to habitat structure, FID increased when vegetation cover decreased. On the other hand, FID and group size were not affected by slope. Our study shows that guanacos respond to poaching pressure as do other ungulate species, and that other factors such as vegetation cover also affect this behavior. Managers should be aware when interpreting FID due to its relation to habitat structure; the guanaco appears to assume greater risk (lower FID) in areas with high vegetation cover. [ABSTRACT FROM AUTHOR]

A rocky habitat, in its broadest sense, may be described as any locality that contains boulders, rocks, scree, pebbles, outcrops, cliffs, or caves. In these habitats, mammals find shelter sites that they use as nesting sites or dens to raise their young in a stable microclimate that is relatively secure from predators. The aim of this study was to characterize and evaluate the microhabitat selection by the southern mountain cavy (Microcavia australis Geoffroy and d'Orbigny) in a rocky habitat. This rodent selected the highest and deepest crevices, which provided them with a more stable microenvironment than outside. The present study is the first to report a southern mountain cavy population associated with a rocky habitat, suggesting a strong plasticity to inhabit a variety of habitats, as indicated by its wide distribution. [ABSTRACT FROM AUTHOR]

Hoarding food is an important strategy of rodents in desert environments characterized by unpredictable and poor food resource availability. In the Monte Desert, Prosopis produces abundant food, unevenly in time and space, in the form of pods and seeds. Sigmodontine rodents ( Graomys griseoflavus, Akodon molinae, Eligmodontia typus and Calomys musculinus) use Prosopis propagules extensively, and they could be predators or dispersers depending on how they handle and where they leave the propagules. The objectives of this study were: (1) to know what rodent species transported propagules; (2) to evaluate what hoarding pattern was used by species that transport propagules (larder and scatterhoarding); and (3) to analyse in which condition were propagules left by the rodent species, both at the food source and in caches. Our results showed that all four species transported propagules, with G. griseoflavus and E. typus being the species that carried more seeds. Our study supported the evidence that food caching is common among species and that many species both larderhoard and scatterhoard food. Graomys griseoflavus and A. molinae, the largest species, larderhoarded more than did the smaller E. typus. These results uphold the hypothesis that larger species will show greater propensity to larderhoard than smaller species. Considering the interaction between seed-hoarding patterns and plants, E. typus was the species that could most improve germination because it scatterhoarded propagules and left seeds out of pods. In contrast, G. griseoflavus could have a negative impact on plant populations because this was the species that predated more seeds and larderhoarded a high percentage of them. The smallest C. musculinus was the species that transported propagules least, and left them as seeds inside pods or pod segments mainly at the food source, which makes seeds more vulnerable to predation. [ABSTRACT FROM AUTHOR]

Abstract: Habitats vary not only in resource availability and quality but also in predation risk, among other factors. The Desert Puna of Argentina comprises two habitats: the shrub steppe and the vegas. The former, the most abundant habitat, is a topographically simple area with unavailable free water and poor food quality; the latter is a very scarce and topographically complex habitat and with water available year round and high quality food. Guanaco relies heavily on vision to detect predators and narrow and complex habitats would be risky. Hence, we expected that guanacos would use the vegas in lowest proportion and would increase the time devoted to vigilance. Guanacos spent more time in the shrub-steppe than in the vegas, where the highest percentage of vigilant guanacos was recorded. A positive and significant relationship between time devoted to foraging and number of animals per herd was observed in both habitats. In the shrub-steppe the opposite was observed for vigilance, whereas in the vegas, no relationship was observed. Despite the low availability of vegas and the high predation risk, they represent a critical habitat for guanacos in the Desert Puna, because they representing the only areas with free water available throughout year for wildlife. [Copyright &y& Elsevier]