New Data on Armadillos (Xenarthra: Dasypodidae) for Central Patagonia, Argentina

Armadillos represent the most diverse family of xenarthrans. Although many studies have been done on these mammals, several topics, such as their local distribution, natural history, behavioral ecology and conservation, remain poorly known. Chaetophractus villosus and Zaedyus pichiy are the most common armadillos in extra-Andean Patagonia, a vast area in southern Argentina and Chile that encompasses different ecosystems and has been modified by human activities, mainly by sheep grazing. In this work we present new data on the distribution, natural history, conservation, and ecology of C. villosus and Z. pichiy from central Patagonia (Chubut and Río Negro provinces, Argentina). We registered 60 localities for C. villosus and 35 for Z. pichiy that confirm their presence in wide sectors of central Patagonia. Furthermore, we confirmed that these two armadillo species suffer high rates of mortality due to their use as a protein source, hunting by dogs, road traffic, and poisoning, among others. We conclude that their populations are at risk of overexploitation and local extinction. The basic knowledge provided here will be a first step towards the conservation of these characteristic Patagonian mammals.Fil: Abba, Agustin Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Nabte, Marcela Janina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Udrizar Sauthier, Daniel Edgardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentin

Land mammals of Península Valdés: Annotated checklist

Los estudios sobre mamíferos terrestres de la Patagonia árida son fragmentarios en comparación al conocimiento disponible para los mamíferos marinos. El Área Natural Protegida Península Valdés (ANP-PV) con sus 400 000 ha es una de las áreas protegidas más grandes de la estepa patagónica. Aquí se brinda una lista actualizada de las especies de mamíferos terrestres que habitan el ANP-PV, reuniendo la información publicada y complementada con información inédita. La fauna de mamíferos nativa del ANP-PV está compuesta por 22 especies, agrupadas en 21 géneros, 10 familias y seis órdenes. El orden más numeroso es el de los roedores, con 10 especies agrupadas en 9 géneros y 3 familias. La familia Cricetidae es la más diversa contando con 5 géneros y 6 especies. Asimismo, deben agregarse 6 especies de mamíferos exóticos que habitan en distintas áreas del ANP-PV. Se comenta la posible dispersión de una séptima especie introducida, Oryctolagus cuniculus, la cual podría estar en su fase inicial de expansión.Studies on land mammal species inhabiting Patagonian semi-deserts are fragmentary, particularly when compared to marine mammals. The Protected Natural Area Península Valdés (ANP-PV) has 400 000 ha being one of the largest protected areas in the Patagonian steppe. Here we present an annotated checklist of the land mammals of ANP-PV, based on compiled information from scientific literature and unpublished field and laboratory work. The native mammals of Península Valdés included 22 species belonging to 21 genera, 10 families, and 6 orders. Rodentia is the largest order represented with 10 species belonging to 9 genera and 3 families. Cricetidae is the most diverse family, with 5 genera and 6 species. Six exotic mammalian species inhabit the area. We discuss the possible dispersion of a seventh introduced species, Oryctolagus cuniculus, which could be in its initial phase of expansion.Fil: Nabte, Marcela Janina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Saba, Sergio Leonardo. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Monjeau, Jorge Adrian. Universidad Atlantida Argentina; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

New Data on Armadillos (Xenarthra: Dasypodidae) for Central Patagonia, Argentina

Armadillos represent the most diverse family of xenarthrans. Although many studies have been done on these mammals, several topics, such as their local distribution, natural history, behavioral ecology and conservation, remain poorly known. Chaetophractus villosus and Zaedyus pichiy are the most common armadillos in extra-Andean Patagonia, a vast area in southern Argentina and Chile that encompasses different ecosystems and has been modified by human activities, mainly by sheep grazing. In this work we present new data on the distribution, natural history, conservation, and ecology of C. villosus and Z. pichiy from central Patagonia (Chubut and Río Negro provinces, Argentina). We registered 60 localities for C. villosus and 35 for Z. pichiy that confirm their presence in wide sectors of central Patagonia. Furthermore, we confirmed that these two armadillo species suffer high rates of mortality due to their use as a protein source, hunting by dogs, road traffic, and poisoning, among others. We conclude that their populations are at risk of overexploitation and local extinction. The basic knowledge provided here will be a first step towards the conservation of these characteristic Patagonian mammals.Facultad de Ciencias Naturales y Muse

New Data on Armadillos (Xenarthra: Dasypodidae) for Central Patagonia, Argentina

Armadillos represent the most diverse family of xenarthrans. Although many studies have been done on these mammals, several topics, such as their local distribution, natural history, behavioral ecology and conservation, remain poorly known. Chaetophractus villosus and Zaedyus pichiy are the most common armadillos in extra-Andean Patagonia, a vast area in southern Argentina and Chile that encompasses different ecosystems and has been modified by human activities, mainly by sheep grazing. In this work we present new data on the distribution, natural history, conservation, and ecology of C. villosus and Z. pichiy from central Patagonia (Chubut and Río Negro provinces, Argentina). We registered 60 localities for C. villosus and 35 for Z. pichiy that confirm their presence in wide sectors of central Patagonia. Furthermore, we confirmed that these two armadillo species suffer high rates of mortality due to their use as a protein source, hunting by dogs, road traffic, and poisoning, among others. We conclude that their populations are at risk of overexploitation and local extinction. The basic knowledge provided here will be a first step towards the conservation of these characteristic Patagonian mammals.Facultad de Ciencias Naturales y Muse

Range Management Affects Native Ungulate Populations in Penísula Valdés, a World Natural Heritage

Sheep rearing is the main productive activity in Patagonian rangelands, where guanacos are the only native ungulate. Ranchers perceive a decrease in range carrying capacity as guanaco numbers increase, therefore guanaco conservation within private lands becomes a considerable challenge. This issue is particularly evident in the World Natural Heritage Penı´nsula Valde´s (PV), where there is a need to harmonize livestock production and biodiversity conservation. While sheep rearing prevails as the primary land use in the area, some ecotourism initiatives have been implemented to complement livestock production. In order to study how land use affected guanaco distribution, we characterized PV’s ranches in termsof land subdivision, primary productivity, stocking-rate and management type, and assess how these variables affected guanaco encounter rates. Smaller ranches were composed of smaller paddocks (mean size 4.8 km2 ), which showed highervalues of the remote-sensing derived Enhance Vegetation Index (EVI) (mean 0.14) and held higher sheep densities (mean 108.0 sheep/km2 ), while larger management units (mean size 23.8 km2 ), showed lower EVI values (mean 0.12) and lower stocking-rates (mean 36.7 sheep/km2). This pattern suggests that primary productivity has been a decisive factor to determine the minimal paddock size set by ranchers in PV, apparently precluding excessive land-subdivision in less productive areas. Guanaco encounter rate, expressed as number of guanacos per travelled kilometre, was inversely relatedto EVI and stocking-rate. However, land subdivision was the better predictor of guanaco encounter-rate within only sheep ranches, finding more guanacos per kilometre as paddock size increased. In contrast, in ranches where ecotourism was implemented as a complementary activity, guanaco encounter-rates were greater, regardless of paddock size. Our results suggest that the implementation of an additional activity by which landowners derive benefits from wildlife has prompted a beneficial outcome for guanacos, presumably through a decrease in harassment intensity. Finally, we propose possible mechanisms by which land subdivision may affect guanaco distribution and potential alternatives for the inclusion of wildlife conservation in a context of extensive livestock production.Fil: Nabte, Marcela Janina. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Nacional Patagonico;Fil: Marino, Andrea Ivana. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Nacional Patagonico;Fil: Rodriguez, Maria Victoria. Consejo Nacional de InvesOt.cientif.y Tecnicas. Centro Nacional Patagonico;Fil: Monjeau, Jorge Adrian. Consejo Nacional de Invest.cientif.y Tecnicas;Fil: Saba, Sergio Leonardo. Universidad Nacional de la Patagonia "san Juan Bosco"

Diet of magellanic horned owl (Bubo magellanicus) in monte desert and argentine Patagonia

Se analizó la dieta del Búho Magallánico (Bubo magellanicus) a partir de 1232 presas obtenidas en 346 egagrópilas provenientes de ocho localidades emplazadas en el Desierto del Monte y la Patagonia (Argentina). En seis de las ocho localidades, el Búho Magallánico consumió exclusivamente pequeños mamíferos, principalmente roedores. El análisis de las contribuciones de biomasa evidenció que, en todas las muestras, una o dos presas de mamíferos constituyeron más del 50%. La riqueza específica de los mamíferos osciló entre 7 y 11 taxones. En una de las muestras, correspondiente a verano y durante el período de cría, se registró el consumo de decápodos dulceacuícolas (Aegla sp.) y elevados porcentajes (> 30%) de otros invertebrados. Finalmente, se discuten críticamente los antecedentes existentes en la literatura sobre la dieta del Búho Magallánico en la Patagonia argentina.We studied the diet of the Magellanic Horned Owl (Bubo magellanicus) based on 1232 preys from 346 pellets collected at eight localities in Monte Desert and Patagonia (Argentina). In six of the eight localities, this owl consumed exclusively small mammals, mainly native rodents. The analysis of the biomass input showed that, for all studied samples, one or two mammal species accounted for > 50% of the eaten prey. Specific richness for mammals ranged between 7 and 11 taxa. In one sample, corresponding to the summer and breeding period, we registered the consumption of fresh-water decapods (Aegla sp.) and high percentages (> 30%) of other invertebrates. Finally, we critically review the literature on the diet of the Magellanic Horned Owl in the Argentinean PatagoniaFil: Nabte, Marcela Janina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Saba, Sergio Leonardo. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentin

Are owl pellets good estimators of prey abundance?

Some ecologists have been skeptics about the use of owl pellets to estimate small mammal's fauna. This is due to the assumptions required by this method: (a) that owls hunt at random, and (b) that pellets represent a random sample from the environment. We performed statistical analysis to test these assumptions and to assess the effectiveness of Barn owl pellets as a useful estimator of field abundances of its preys. We used samples collected in the arid Extra-Andean Patagonia along an altitudinal environmental gradient from lower Monte ecoregion to upper Patagonian steppe ecoregion, with a mid-elevation ecotone. To test if owls hunt at random, we estimated expected pellet frequency by creating a distribution of random pellets, which we compared with data using a simulated chi-square. To test if pellets represent a random sample from the environment, differences between ecoregions were evaluated by PERMANOVAs with Bray–Curtis dissimilarities. We did not find evidence that owls foraged non-randomly. Therefore, we can assume that the proportions of the small mammal's species in the diet are representative of the proportions of the species in their communities. Only Monte is different from other ecoregions. The ecotone samples are grouped with those of Patagonian steppes. There are no real differences between localities in the small mammal's abundances in each of these ecoregions and/or Barn owl pellets cannot detect patterns at a smaller spatial scale. Therefore, we have no evidence to invalidate the use of owl pellets at an ecoregional scale.Fil: Andrade, Analia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Menezes, Jorge Fernando Saraiva de. Universidade Federal do Rio de Janeiro; BrasilFil: Monjeau, Jorge Adrian. Universidade Federal do Rio de Janeiro; Brasil. Fundación Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

EFFECT OF BETA-MANNANASE ENZYME ADDITION TO SOY-CONTAINING MILK REPLACERS ON GROWTH AND HEALTH OF NEONATAL DAIRY CALVES

First work carried out in calves fed soy protein in Milk Replacer that obtained similar growth rates than animals fed whey protein based Milk Replacer.The increasing cost of milk proteins is forcing the milk replacer industry to evaluate alternative protein sources to make more cost effective products. Alternative proteins should contain an appropriate amount of crude protein that is digestible with an adequate amino acid profile. Among the available protein sources, soy protein appears to be good alternative because of the protein content, availability, and lower cost compared with the milk proteins. However, soybean contains anti-nutritional factors such as trypsin inhibitor, lectins, and non-starch polysaccharides and inclusion of soy proteins in milk replacer has resulted in reduced growth and health in preruminant calves. The use of exogenous enzymes such as mannanases in poultry and swine has shown improved performance in the digestibility of soy-based feeds. The aim of this study was to evaluate the effects of soy-containing milk replacer with the addition of mannanase-based enzymes on growth and health of pre-ruminant Holstein bull calves. Two milk replacers were used for this experiment, a commercially available whey based milk replacer (28% CP and 15% fat) and a specially formulated soy protein containing milk replacer with fifty percent of the protein replaced by the soy protein concentrate. Fifty-six calves (n=14 per treatment, four treatments) were assigned to treatments consisting of either the all whey protein, or the soy protein milk replacer without mannanase based enzymes or two additional treatments fed two concentrations of mannanase based enzymes. The calves were provided 0.28 Mcal gross energy/kg BW0.75 the first seven days and 0.32 Mcal gross energy/kg BW0.75 until day 21 when the absolute amount was held constant to maintain adequate inventory of milk replacer for the 56-day study. On day 36 a commercial calf starter was provided to the calves on an ad libitum basis, and a step down weaning process weaning occurred at day 56 with complete starter removal and weaning by day 63. Initial (53.6 +-6.4 Kg) and final (111.2 +- 10.7 Kg) body weights were not significantly different, thus average daily gain (0.91 +-0.14 kg/d) was not different among treatments. Among treatments, dry matter intake (1.64 +-0.25 kg/d) and overall feed efficiency (gain:feed, 0.56 +-.07) was not different. Differences were not detected among treatments for health, fecal score and body condition score (P > 0.10). A cost analysis was conducted and the cost per kilogram of gain of calves fed the soy protein concentrate milk replacer with the mannanase based enzymes was approximately 30% lower than calves fed the whey based milk replacer. Therefore, in this experiment, the use of soy protein concentrate with the mannanase-based enzymes provided similar animal performance as whey proteins and decreased the cost of production.This Work was sponsored by the Cornell University Animal Science Department and the ChemGen Corp. Student received an scholarship from USAID