En este trabajo se presentan los resultados del análisis de los restos faunísticos de Hangar, un sitio arqueológico ubicado en la región pampeana argentina. Los fechados realizados sobre huesos de guanaco sitúan cronológicamente a las ocupaciones humanas en el Holoceno tardío final, período escasamente representado en el área. Los análisis tafonómicos y estratigráficos indican que el sitio presenta complejos procesos de formación, con una baja integridad, aunque con buena resolución. Los principales procesos que afectaron a los restos fueron la bioturbación y las tareas de laboreo de la tierra. Las evidencias aportadas por Hangar muestran la explotación de distintos taxones, entre los que se destacan el guanaco, el venado de las Pampas, la vizcacha, el peludo y el ñandú. Estos datos constituyen un importante insumo para el creciente avance en el conocimiento de la subsistencia de los cazadores-recolectores que habitaron la región pampeana. En particular, los fechados-taxón obtenidos aportan nuevos datos para la discusión acerca de la retracción del guanaco en momentos tardíos en el área Interserrana bonaerense.

The vicuna is mainly used in two ways: wild captured, shorn and returned to the wild; or wild captured and maintained in captivity as part of a programme of sustainable use in the Andes of South America. Farming of wild vicunas has hitherto involved no assessment of their welfare. In this study we measured a set of basic blood parameters in order to characterise baseline values in captivity, and we then characterised adrenal cortical responsiveness using an ACTH challenge. The ACTH challenge is widely used for assessing neuroendocrine responses to stress and is now increasingly being applied to studies of wild animals’ welfare. Five male vicunas were injected with exogenous ACTH and their responses compared with those of a control group injected with placebo. Behavioural and haematological changes were monitored. Injection of ACTH produced a 4.5-fold increase in cortisol concentration within 1 h. Total white blood cell count almost doubled in less than 5 h. The neutrophil:lymphocyte ratio also changed, with a decrease in lymphocytes and an increase in neutrophils, suggesting that the neutrophil:lymphocyte ratio was affected by the ACTH challenge. Packed cell volume increased from 40% to 44%. Observations of individual vicunas during sampling revealed no discernible behavioural differences between treated and control animals; however, animals that had higher initial baseline cortisol concentration made more attempts to escape, and vocalised more during handling, regardless of whether they were treated with ACTH or placebo. The results reveal the different blood parameter levels associated with stress in different species and highlight the hazard of interpreting stress levels in one species on the basis of measures calibrated in another. We provide calibrated reference values for future studies of stress in vicunas.

Current procedures for ranching and sustainable use of guanacos necessitate their transport. Transportation is a risky process for animals, and is a particular concern for wild-caught or semi-domesticated species such as the guanaco — a wild South American camelid species increasingly being established on farms in Chile and Argentina. This study investigated the effect of transport on the physiological and behavioural responses of eight castrated adult male guanacos, transported on a single 2 h journey at a stocking density of 113.5 kg m-2 (0.76 m2 per animal). Plasma cortisol and blood glucose concentration, total and differential white blood cell (WBC) counts, heart rate, and body weight were measured one week before, immediately before, immediately after, 2 h after and one week after transport. Behavioural responses were recorded during handling prior to loading. Immediately after transport we found significant increases in plasma cortisol concentrations and neutrophil:lymphocyte (N:L) ratio, the latter peaking 2 h after transport. Heart rate increased significantly only during loading, while body weight remained constant throughout. Behavioural responses related to handling (jumping, vocalising, kicking, spitting and urinating) were not associated with the physiological response. All variables returned to pre-transport values within one week. Transport of guanacos under these conditions produced physiological changes similar to those associated with a mild and transient stress response in other species and which, we judge, fall comfortably within acceptable limits for their welfare.

Research in two distinct steppe landscapes in southern Patagonia—the western basaltic plateaux and the central Deseado Massif—compares hunter-gatherer strategies in the two environments, focusing on the use of hunting blinds and associated tactics in the hunting of guanaco. The evidence obtained brings this region into discussions about the use of rocky structures and the recognition of tactics used for hunting ungulates in a global perspective. The authors also emphasise the importance of highland settings as major and reliable sources of critical resources for foraging peoples, a topic still not fully appreciated in archaeological studies of hunter-gatherers.

Argentina's annual camelid fibre production is estimated at 60 000 kg for llama (Lama glama), somewhat more than 2 000 kg for guanaco (Lama guanicoe) and about 845 kg for vicuña (Vicugna vicugna). The potential for increasing these amounts is huge considering that barely 30 percent of llamas are shorn and considering the size of the wild camelid population in the country. A compilation of published and unpublished work confirms that almost 50 percent of the llamas are single-coated, about 40 percent have white fleeces and that average fibre diameter is about 22 µm in the main llama production area. In general, there is a wide variation in fleece weights and fibre quality between and within herds. However, a llama fleece classing and pricing system is not yet in place to motivate implementation of breeding programmes. Guanaco and vicuña fleeces are double-coated but the fine undercoat represents more than 80 percent of the fleece weight. The proportion of down fibre remaining after mechanical dehairing is only 50 percent in guanacos and 70 percent in vicuñas. The guanaco undercoat fibre diameter is about 16 µm and vicuña fibre diameter is typically between 13 and 14 µm. Both fibres are relatively short. Research is needed to establish optimum shearing season and shearing frequency that results in fibre quality demanded for handcraft and industry in each of the three species.

We report changes in guanaco Lama guanicoe density, recruitment, and social structure associated with increased access of poachers along an extensive network of hydrocarbon-exploration roads in northern Patagonia, and conservation measures taken in response. Mean guanaco densities declined 93–96% and mean group size declined from 9.8 to 5.0 guanacos per group at three sites surveyed during 1982–1983 and 2002–2007, whereas yearling proportions did not change significantly. Additional surveys during 2002–2007 suggest population declines and fragmentation have occurred over a wide area of intense hydrocarbon exploration and extraction. Guanaco densities in 2002–2007 showed a strong negative association with the density of access points along hydrocarbon-exploration roads and, to a lesser degree, with livestock densities. The increase in poaching in recent decades, resulting from increased access and an urban population that has appropriate vehicles, has probably been the main cause of the decline of the guanaco population, although overgrazing by livestock and decreased plant productivity may also be contributing factors. Closing of exploration roads with levees and ditches in 2006 and 2010 by a hydrocarbon company, under supervision by the local government and scientists, restricted access by unauthorized vehicles to a 220,000-ha area, including two of the sites where guanaco numbers collapsed. This action, in combination with increased ranger patrols, may allow guanaco recovery in the coming years.

Conservation interventions increasingly involve active management of relative species abundances, especially when taxa of conservation concern are threatened by complex food web interactions. Unfortunately, the complexity of such interspecific interactions means that well-meaning management interventions can have unexpected, sometimes detrimental, effects on the species they are intended to protect. Here we report that the abrupt removal of an abundant non-native prey species (domestic sheep) and the cessation of predator control, actions intended to protect huemul deer Hippocamelus bisulcus in the future Patagonia National Park, appear to have had negative effects on this Endangered ungulate. During and following the changes in predator–prey management, predation of huemul fawns and females older than 1 year by native culpeo foxes Lycalopex culpaeus and pumas Puma concolor increased 3- and 5-fold, respectively. Predictions from demographic models suggest that elevated mortality rates of female huemul older than 1 year will, on average, cause this population of huemul to decline. These results highlight risks of unintended consequences when aggressive management actions are taken to protect taxa embedded in complex food webs. They also suggest that careful consideration of both inter- and intra-trophic level effects among all species in a system is warranted before conservation interventions are undertaken.

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.

More than one million smallholders in the Andean region of central South America exploit alpacas (Vicugna pacos) and lamas (Lama glama) as their main means of subsistence. Alpacas and lamas provide meat, milk, fibre, power and guano; in addition it is an important element of the cultural identity of their producers. With 3.9 million lamas and 3.3 million alpacas the total annual fibre production in the region exceeds 5 million kg. Nearly 30% of the fibre production is transformed on-farm or at the community level. About 80% of the marketed alpaca fibre is white and 12% is finer than 23 microns. Lama fibres have less value and are more variable in colours and fibre diameter than alpaca fibres. Both species of camelids have two breeds, each one with specific adaptation and fibre quality characteristics. Two wild species of camelids exist in South America: the guanaco (Lama guanicoe) and the vicuna (Vicugna vicugna). Both have fleeces with precious down fibres. Specific populations of these camelids are qualified to be captured, sheared and released, providing an additional income to the communities in which they live. Due to support to improve the production of fibre and other products of South American camelids, while preserving a valuable animal genetic resource, the cultural values of the associated production systems, and improving the livelihoods of resource-poor smallholders should be part of a global strategy involving a sustained investment in appropriate R&D.

Mammalian herbivores can play a role in the endozoochorous dispersal of Prosopis seeds in the arid zones of Argentina, and the introduction of exotic mammals can change relevant parameters of the plant's reproductive ecology. Our specific goals were to quantify the seeds of Prosopis flexuosa, P. chilensis and P. torquata contained in the faeces of native [mara (Dolichotis patagonum), guanaco (Lama guanicoe)] and exotic [donkey (Equus asinus) and hare (Lepus europaeus)] mammals, and to determine the mortality, germination percentage and germination speed of seeds borne in faeces, compared with those collected from trees. In 2006, seeds were collected directly from trees or removed from mammal faeces. Seeds were counted and classified as apparently healthy or damaged. P. torquata and P. flexuosa seeds were found in the dung of guanaco, hare and mara, whereas only P. flexuosa seeds appeared in donkey faeces. P. chilensis seeds were only found in guanaco faeces. There was a notable relative abundance of seeds contained in small herbivore faeces in comparison to the large herbivores. The passage through the digestive tract of animals modified seed germination capacity and speed, with great variability between animal species. Guanacos had greater effects than donkeys on mortality, germination percentage and germination speed. Differences between the effects of both smaller-sized herbivores on seeds were much smaller.