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The Argentinian Ministry of Environment has approved the translocation of 45 guanacos from Southern Patagonia to the Pampas region, a distance of 1500 km, as the initial phase toward future translocations into a National Park located in the Chaco region, another 1600 km further North. This decision raises concerns about the technical and ethical aspects of the translocation. Firstly, there is a lack of proper evaluation and scientific evidence to support the need, opportunity, and feasibility of this translocation. The guanaco population is currently over one million and is increasing, and genetic differences exist among local populations. The translocation could produce anthropogenic‐driven admixed populations, leading to genetic swamping and disrupting evolutionary processes. Second, there are ethical conflicts around managing wild species populations that prioritize private objectives and disregard local, publicly funded science. Rewilding projects require a deep understanding of interacting ecosystem processes, and of the socio‐economic context. This management decision violates guiding principles for rewilding and should have followed proper scientific evaluation and transparent local consultation. [ABSTRACT FROM AUTHOR]

We characterized the habitat use by maras (Dolichotis patagonum) on a microhabitat scale in the area surrounding the warren, assessing the conditioning effect of the warren over space use and exploitation of other resources. We evaluated the relationships between the probability and intensity of use, habitat configuration and distance to the warren, counting feces along transects departing from each warren. Our results showed that the location of breeding warrens was positively associated with the habitat use by maras on a microhabitat scale. The core area of the annual activity of maras was concentrated around the warren and there was no evidence of alternative areas of activity. According to the fitted models, maras used microhabitats with a high proportion of bare soil and close to infrastructure elements. The spatial autocorrelation components indicated that intensively used patches are small and disperse. The patterns of habitat use observed in this study suggest that maras use multipurpose areas including the breeding site and resources needed throughout the year. These patterns suggest that warrens are good all year-round indicators of mara habitat use and spatial ecology. [ABSTRACT FROM AUTHOR]

There is an urgent need to characterize the relationships between endangered species and their habitats in response to the accelerating pace of habitat transformation by humans. Mara (Dolichotis patagonum) is a large rodent endemic to the Argentine semi-deserts. It has been classified as “Near Threatened” by IUCN mainly as the result of habitat loss. There is contradictory evidence about the impact of human activities on mara and further information is needed to develop effective conservation strategies. We describe the main environmental factors, both natural and human, that are associated with warren presence as an indicator of the habitat selected by maras at the landscape scale. Habitat selected by maras was characterized by a high proportion of bare soil, low β diversity, open herbaceous steppe, and proximity to fences. The relationship of warren presence to the proportion of shrubby steppe in the broader landscape was variable across environments being positive in grasslands, and negative in shrubbier habitats. This supports the hypothesis that mara's preference for open areas depends on the level of shrubs in the surrounding habitat. As a result, conservation efforts will need to be tailored to the amount and structure of vegetation in any given area. [ABSTRACT FROM AUTHOR]

In Patagonia, the functional relationships between pumas and their native prey species have been modified as a result of the introduction of exotics. We studied the feeding habits of Puma concolor in northeastern Chubut province during 3 years and found that (1) the native guanaco, Lama guanicoe, was the most important prey in the diet of pumas; (2) pumas expanded their trophic niche by incorporating smaller prey species to their diets after a substantial reduction in the abundance of the introduced sheep; and (3) puma predation was the main cause of guanaco mortality. [ABSTRACT FROM AUTHOR]

For large herbivores, predation-risk, habitat structure and population density are often reported as major determinants of group size variation within and between species. However, whether the underlying causes of these relationships imply an ecological adaptation or are the result of a purely mechanistic process in which fusion and fragmentation events only depend on the rate of group meeting, is still under debate. The aim of this study was to model guanaco family and bachelor group sizes in contrasting ecological settings in order to test hypotheses regarding the adaptive significance of group-size variation. We surveyed guanaco group sizes within three wildlife reserves located in eastern Patagonia where guanacos occupy a mosaic of grasslands and shrublands. Two of these reserves have been free from predators for decades while in the third, pumas often prey on guanacos. All locations have experienced important changes in guanaco abundance throughout the study offering the opportunity to test for density effects. We found that bachelor group size increased with increasing density, as expected by the mechanistic approach, but was independent of habitat structure or predation risk. In contrast, the smaller and territorial family groups were larger in the predator-exposed than in the predator-free locations, and were larger in open grasslands than in shrublands. However, the influence of population density on these social units was very weak. Therefore, family group data supported the adaptive significance of group-size variation but did not support the mechanistic idea. Yet, the magnitude of the effects was small and between-population variation in family group size after controlling for habitat and predation was negligible, suggesting that plasticity of these social units is considerably low. Our results showed that different social units might respond differentially to local ecological conditions, supporting two contrasting hypotheses in a single species, and highlight the importance of taking into account the proximate interests and constraints to which group members may be exposed to when deriving predictions about group-size variation. [ABSTRACT FROM AUTHOR]

We conducted focal observations of territorial guanacos, a highly polygynous and social mammal, to compare time budgets between sexes and test the hypothesis that the differences in reproductive interests are associated with differential group size effects on male and female time allocation patterns. In addition, we used group instantaneous sampling to test the hypothesis that grouping improves detection capacity through increased collective vigilance. We fit GLM to assess how group size and group composition (i.e., presence or absence of calves) affected individual time allocation of males and females, and collective vigilance. As expected from differences in reproductive interests, males in family groups devoted more time to scan the surroundings and less to feeding activities compared to females. Both sexes benefited from grouping by reducing the time invested in vigilance and increased foraging effort, according to predation risk theory, but the factors affecting time allocation differed between males and females. Group size effects were significant when females were at less than five body-lengths from their nearest neighbour, suggesting that grouping benefits arise when females are close to each other. Female time budgets were also affected by season, topography and vegetation structure. In contrast to our expectation, males reduced the time invested in vigilance as the number of females in the group increased, supporting the predation risk theory rather the intrasexual competition hypothesis. The presence of calves was associated with an increase in male individual vigilance; and vegetation type also affected the intensity of the group size effect over male time allocation. In closed habitats, collective vigilance increased with the number of adults but decreased with the number of calves present. Although male and female guanacos differed in their time allocation patterns, our results support the hypothesis that both sexes perceive significant antipredator benefits of group living. [ABSTRACT FROM AUTHOR]

Guanacos (Lama guanicoe) are the largest native Artiodactyl in South America and the most widely distributed. In arid Patagonia, densities are low and negatively related to domestic sheep numbers in space and time consistent with interspecific competition theory. Although guanacos and domestic sheep have been described as intermediate feeders sharing food resources, no studies have been conducted to compare their diets in sympatric conditions and explore whether the potential exists for direct interspecific competition. We assessed the diet of both species across 9 different sites and 2 seasons by microhistological analysis of fecal samples. We found that (1) guanacos and sheep are generalist herbivores feeding on a wide range of plant species; (2) both are intermediate feeders able to include both monocotyledoneous and dicotyledoneous plants in their diet; (3) both are able to change their diets seasonally; and (4) food niche overlap is high, particularly in summer when food resources are more scarce than in spring. We conclude that the potential for competition between guanacos and sheep is high and could have played a major role in the demise of guanacos. Consequently, current management practices focused on maximizing sheep numbers are not compatible with the recovery of guanaco populations. [ABSTRACT FROM AUTHOR]

Simple Summary: Determining the impacts of human activities on natural populations is important for biodiversity conservation. In this paper, we study the past and more recent effects of urbanization and livestock activity on the genetic diversity and population structure of endemic guanaco populations of the arid Monte and Patagonian Steppe of central Argentina. Our results reveal that urbanization, the installation of fences, and the competition from sheep grazing coincided with the isolation of several guanaco populations, especially in areas with the highest intensity of livestock activity. However, our genetic analyses suggest that a more recent increase in connectivity among groups is occurring. Our results highlight the importance of implementing conservation management plans for natural populations in arid and human-intervened environments. Extensive livestock production and urbanization entail modifications of natural landscapes, including installation of fences, development of agriculture, urbanization of natural areas, and construction of roads and infrastructure that, together, impact native fauna. Here, we evaluate the diversity and genetic structure of endemic guanacos (Lama guanicoe) of the Monte and Patagonian Steppe of central Argentina, which have been reduced and displaced by sheep ranching and other impacts of human activities. Analyses of genetic variation of microsatellite loci and d-loop revealed high levels of genetic variation and latitudinal segregation of mitochondrial haplotypes. There were indications of at least two historical populations in the Monte and the Patagonian Steppe based on shared haplotypes and shared demographic history among localities. Currently, guanacos are structured into three groups that were probably reconnected relatively recently, possibly facilitated by a reduction of sheep and livestock in recent decades and a recovery of the guanaco populations. These results provide evidence of the genetic effects of livestock activity and urbanization on wild herbivore populations, which were possibly exacerbated by an arid environment with limited productive areas. The results highlight the importance of enacting conservation management plans to ensure the persistence of ancestral and ecologically functional populations of guanacos. [ABSTRACT FROM AUTHOR]

Focuses on the Guanacos, a modern-day South American Camelid which exist in Patagonia. Examination of the species' habits; Background on breeding and birth patterns; Identification of challenges which confront this animal; Details on th

Reports on the death of guanacos in Cabo Dos Bahias Provincial Reserve in the Argentine Patagonia. Number of guanacos that died; Potential cause of the death; Condition of guanacos in Cabo Dos Bahias.

Mammals are key components of biodiversity mediating ecosystem functions, mainly because of the diversity of forms and functions of this group. Understanding and making explicit the role of mammals underpinning Nature's Contributions to People (NCP) or directly contributing to human well-being would help to influence policy formulation towards sustainable development and nature conservation. Through a workshop held at the XXXII Jornadas Argentinas de Mastozoología and subsequent collaborative work, we compiled information related to Mammal's Contributions to People in Argentina (MCP-Arg) based on participants' interpretation of the available literature and their field experience. Argentinian mammals contribute to 12 of the 18 defined NCPs. We derived numerous MCP-Arg from studies that focused mainly on ecological processes and conservation, revealing an information gap in MCP-Arg description, quantification, and mapping. All taxa contribute similarly to the overall contributions, highlighting the importance of preserving mammal diversity. Conservation should also be framed at the local community rather than regional scales, aiming to preserve ecological functioning and contributions to human well-being, especially within regulation contributions. Our results show destructive feedback between threats and habitat-related contributions, with habitat degradation being the greatest threat to mammalian contributions and habitat maintenance the most threatened one. Our research indicates that a substantial amount of knowledge about MCP-Arg is available through narratives and interpretations. Considering the NCP approach to mammalian research, we can make significant contributions to both mammal conservation and human well-being. [ABSTRACT FROM AUTHOR]

Ungulates living in predator-free reserves offer the opportunity to study the influence of food limitation on population dynamics without the potentially confounding effects of top-down regulation or livestock competition. We assessed the influence of relative forage availability and population density on guanaco recruitment in two predator-free reserves in eastern Patagonia, with contrasting scenarios of population density. We also explored the relative contribution of the observed recruitment to population growth using a deterministic linear model to test the assumption that the studied populations were closed units. The observed densities increased twice as fast as our theoretical populations, indicating that marked immigration has taken place during the recovery phase experienced by both populations, thus we rejected the closed-population assumption. Regarding the factors driving variation in recruitment, in the low- to medium-density setting, we found a positive linear relationship between recruitment and surrogates of annual primary production, whereas no density dependence was detected. In contrast, in the high-density scenario, both annual primary production and population density showed marked effects, indicating a positive relationship between recruitment and per capita food availability above a food-limitation threshold. Our results support the idea that environmental carrying capacity fluctuates in response to climatic variation, and that these fluctuations have relevant consequences for herbivore dynamics, such as amplifying density dependence in drier years. We conclude that including the coupling between environmental variability in resources and density dependence is crucial to model ungulate population dynamics; to overlook temporal changes in carrying capacity may even mask density dependence as well as other important processes. [ABSTRACT FROM AUTHOR]

The guanaco Lama guanicoe was the only large native herbivore widely distributed across Patagonia until the introduction of domestic sheep Ovis aries. Guanacos have declined because of competition with sheep for forage, high hunting pressure and habitat degradation. Península Valdés is a protected area where sheep ranching is the predominant activity. A ranch formerly dedicated to sheep production was converted into a private wildlife reserve, from which all the sheep were removed in 2005. We studied changes in guanaco abundance inside and outside the reserve after sheep removal, and also plant cover of various vegetation types. We found that guanaco abundance was higher inside than outside the reserve, and increased by three-fold within 3 years. Total plant cover and grass cover were higher inside than outside the reserve. Our results showed that guanacos reacted rapidly to changes in management, and suggest that even at a high density guanacos would not be as damaging to the vegetation as sheep. Although management changes resulted in significant changes in guanaco abundance locally, the size of a protected area influences the persistence of wild populations. A large herbivore such as the guanaco needs to be managed across large areas. We believe it is necessary to implement a management plan for Península Valdés that allows for the coexistence of sustainable livestock production and healthy wildlife populations. [ABSTRACT FROM PUBLISHER]

Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action. [ABSTRACT FROM AUTHOR]