Demographic effects of live shearing on a guanaco population

Rey, Andrés; Novaro, Andrés J.; Sahores, Mercedes; Guichón, M. Laura

doi:10.1016/j.smallrumres.2012.05.009

Cited by 10 publications

(11 citation statements)

References 12 publications

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“…The survival rate of shorn guanacos in the Reserve was higher than the rates estimated in the only other reported study on shorn guanacos, at Cabeza de Vaca ranch (Rey et al, 2012b). At Cabeza de Vaca the annual survival rate estimated from telemetry of 17 shorn adult guanacos was 0.70 ± SE 0.11, whereas survival estimated from 1,334 capture-recapture histories was 0.82 ± SE 0.01.…”

Section: Effects On Survival and Reproductioncontrasting

confidence: 58%

Effects of live-shearing on population parameters and movement in sedentary and migratory populations of guanacosLama guanicoe

Carmanchahi

Schroeder

Bolgeri

et al. 2014

Oryx

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Live-shearing of wild guanacos Lama guanicoe may affect their reproductive success and population resilience, and therefore it is important to assess the biological sustainability of obtaining their wool. We evaluated effects of capture and shearing on survival and reproduction, population parameters, daily movements, ranging behaviour and spatial distribution in sedentary and migratory populations. We assessed population variables by radio-telemetry and line-transect surveys before and after capture. We estimated high post-shearing survival rates in both populations and similar yearling production in shorn and non-shorn females in the migratory population. We did not find significant variations in density and population structure before and after shearing in the sedentary population, whereas in the migratory population density decreased and the population structure changed significantly after assembly of the capture structure, returning to pre-assembly levels 1 month later. The mean daily distance moved by radio-collared guanacos during the first 2 days after shearing was three times longer than during the following 30 days. There was a 25% decrease in the mean home-range size of shorn guanacos between the first and second month after shearing but this decline appeared to be associated with a seasonal change in movement, because a similar reduction occurred during the same period the following year, when the guanacos were not shorn. Live-shearing modified the spatial distribution pattern in the sedentary population but did not have a significant effect on the migratory population. Management of guanacos may contribute towards developing a biologically sustainable economic activity that promotes conservation of wildlife and habitats.

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Section: Effects On Survival and Reproductioncontrasting

confidence: 58%

Effects of live-shearing on population parameters and movement in sedentary and migratory populations of guanacosLama guanicoe

Carmanchahi

Schroeder

Bolgeri

et al. 2014

Oryx

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“…The reduction in mean group size between 1982 and 2002–2007 may limit group vigilance, reducing individual foraging time and increasing vulnerability to predators, particularly pumas (Marino & Baldi, 2008; Marino, 2010). The proportion of yearlings at the long-term sites (1983–2007 mean was 0.25 ± SE 0.04) was high compared to other studies (0.00–0.30; Rey et al, 2012; earlier studies cited in Saba et al, 1995) and also in comparison with the Auca Mahuida Volcano site during 2002–2007, where high density may limit birth rates or yearling survival through density dependence. Small group sizes at the long-term sites, however, may limit recruitment from the abundant yearling class into reproductive adults because of reduced group vigilance, individual foraging and predator avoidance.…”

Section: Discussionmentioning

confidence: 49%

GuanacoLama guanicoenumbers plummet in an area subject to poaching from oil-exploration trails in Patagonia

Radovani

Funes

Walker

et al. 2014

Oryx

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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.

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“…Vicuña and guanaco fibre from monitored populations can be obtained either from free ranging animals or from animals kept captive in appropriately fenced paddocks. Recent research confirmed that by applying proper welfare protocols during capture and shearing, population demographics of both species are not altered Rey et al, 2012). The capture and shearing practices of vicuñas and guanacos kept in captivity were described by Amendolara (2001) and , respectively.…”

Section: Fibre Productionmentioning

confidence: 81%

Fibre quality of South American camelids in Argentina: a review

Mueller

Rigalt

Lamas

et al. 2015

Anim. Genet. Resour.

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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. RésuméLa production annuelle de fibres de camélidés de l'Argentine est estimée à 60.000 kg pour le lama (Lama glama), à un peu plus de 2.000 kg pour le guanaco (Lama guanicoe) et à environ 845 kg pour la vigogne (Vicugna vicugna). Le potentiel d'accroissement de ces quantités est énorme compte tenu du fait qu'à peine le 30 pour cent des lamas sont tondus et compte tenu de la taille de la population de camélidés sauvages dans le pays. Une compilation de travaux publiés et non publiés confirme que pratiquement le 50 pour cent des lamas sont à couche unique (sans sous-poil), qu'environ le 40 pour cent ont des toisons blanches et que le diamètre moyen des fibres est de 22 µm dans la principale zone d'élevage de lamas. En général, il existe une grande variation inter-e intra-troupeaux dans le poids des toisons et dans la qualité des fibres. Malgré cela, un système de classement et de tarification des toisons des lamas n'a pas encore été mis en place pour motiver la mise en oeuvre de ce genre de programmes. Les toisons des guanacos et des vigognes sont à double poil mais la bourre représente plus du 80 pour cent du poids de la toison. La proportion de fibres du duvet restantes après épilage mécanique est seulement du 50 pour cent chez les guanacos et du 70 pour cent chez les vigognes. Le diamètre des fibres du duvet est de 16 µm chez le guanaco et de 13-14 µm chez la vigogne. Dans les deux cas, les fibres sont relativement courtes. Des travaux de recherche s'avèrent nécessaires pour déterminer la saison et la fréquence de tonte optimales donnant lieu à la qualité de fibre demandée par les artisans et l'industrie pour chacune des trois espèces.Mots-c...

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Demographic effects of live shearing on a guanaco population

Cited by 10 publications

References 12 publications

Effects of live-shearing on population parameters and movement in sedentary and migratory populations of guanacosLama guanicoe

Effects of live-shearing on population parameters and movement in sedentary and migratory populations of guanacosLama guanicoe

GuanacoLama guanicoenumbers plummet in an area subject to poaching from oil-exploration trails in Patagonia

Fibre quality of South American camelids in Argentina: a review

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