4 research outputs found
Loss of migratory traditions makes the endangered patagonian Huemul deer a year-round refugee in its summer habitat
The huemul (Hippocamelus bisulcus) is endangered, with 1500 deer split into >100 subpopulations along 2000 km of the Andes. Currently occupied areas are claimed-erroneously-to be critical prime habitats. We analyzed historical spatiotemporal behavior since current patterns represent only a fraction of pre-Columbian ones. Given the limited knowledge, the first group (n = 6) in Argentina was radio-marked to examine spatial behavior. Historically, huemul resided year-round in winter ranges, while some migrated seasonally, some using grasslands >200 km east of their current presence, reaching the Atlantic. Moreover, huemul anatomy is adapted to open unforested habitats, also corroborated by spotless fawns. Extreme naivety towards humans resulted in early extirpation on many winter ranges—preferentially occupied by humans, resulting in refugee huemul on surrounding mountain summer ranges. Radio-marked huemul remained in small ranges with minimal altitudinal movements, as known from other subpopulations. However, these resident areas documented here are typical summer ranges as evidenced by past migrations, and current usage for livestock. The huemul is the only cervid known to use mountain summer ranges year-round in reaction to anthropogenic activities. Losing migratory traditions is a major threat, and may explain their presently prevalent skeletal diseases, reduced longevity, and lacking recolonizations for most remaining huemul subpopulations.Fil: Fluck, Werner Thomas. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Norte; Argentina. Universidad de Basilea; Suiza. AdministraciĂłn de Parques Nacionales; ArgentinaFil: Smith Flueck, Jo Anne M.. Universidad Nacional del Comahue; Argentina. Parque Protegido Shoonem; Argentina. Deer Lab; ArgentinaFil: Escobar, Miguel E.. Parque Protegido Shoonem; ArgentinaFil: Zuliani, Melina Elizabeth. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Norte; Argentina. FundaciĂłn Bariloche; ArgentinaFil: Fuchs, Beat. Deer Lab; ArgentinaFil: Geist, Valerius. University of Calgary; CanadáFil: Heffelfinger, James R.. Arizona Game and Fish Department; Estados UnidosFil: Black de Decima, Patricia Ann. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Gizejewski, Zygmunt. Polish Academy of Sciences; ArgentinaFil: Vidal, Fernando. Univerdidad Santo Tomas; Chile. Centro de Conservacion y Manejo de Vida Silvestre; ChileFil: Barrio, Javier. Centro de OrnitologĂa y Biodiversidad; PerĂşFil: Molinuevo, MarĂa Silvina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias BiolĂłgicas; ArgentinaFil: Monjeau, Jorge Adrian. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Norte; Argentina. FundaciĂłn Bariloche; ArgentinaFil: Hoby, Stefan. Berne Animal Park; SuizaFil: JimĂ©nez, Jaime M.. University of North Texas; Estados Unido
The Morphological Basis of vicuña wool: Skin and gland structure in Vicugna vicugna (Molina 1782)
The vicuña (Vicugna vicugna) is the smallest member of the Camelidae with one of the most valuable fibers in the world. However, little is known of the structural basis for this fiber or of the skin glands used in chemical communication in this species. The objective of this study was to examine the histological structure of the skin and hair follicles and the cutaneous glands. Skin samples from the fleece, belly and legs and glandular areas – metatarsal, caudal, anal and interdigital areas – were obtained from animals accidentally killed in captive captures at a government camelid ranch in Jujuy, Argentina. These samples were studied with histological techniques for light and electron microscopy to examine follicular structure and density in fleece compared to belly and leg areas. Glandular areas were similarly studied to determine type and density of skin glands. Compound hair follicles were found with an extremely high density of secondary hairs in relation to primary hairs (S:P ratio) in fleece (42 ± 2, mean ± standard error) and a significantly lesser density (p < 0.001) in belly and legs (12.0 ± 0.7). Follicle and hair diameters from the two areas were also significantly different with the fleece areas having smaller diameters. Secondary hair diameters in fleece were similar to previously published values (13.2 ± 0.3 ÎĽm). With respect to the glandular areas, the metatarsal glands had a striking appearance with an epithelium resembling a hollow honeycomb and a dermis showing a great deal of glandular tissue (simple tubular glands) with excretory ducts. Large sebaceous glands were found in the ventral region of the tail and eccrine sudoriferous glands in the interdigital region. The possible importance of these glands in chemical communication is discussed.EEA BarilocheFil: Chamut, Silvia. Universidad Nacional de Tucuman. Facultad de Agronomia y Zootecnia; ArgentinaFil: Cancino, Andrea Karina. Instituto Nacional de TecnologĂa Agropecuaria (INTA). EstaciĂłn Experimental Agropecuaria Bariloche; ArgentinaFil: Black-Decima, Patricia. Universidad Nacional de Tucuman. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentin
Loss of Migratory Traditions Makes the Endangered Patagonian Huemul Deer a Year-Round Refugee in Its Summer Habitat
The huemul (Hippocamelus bisulcus) is endangered, with 1500 deer split into >100 subpopulations along 2000 km of the Andes. Currently occupied areas are claimed-erroneously-to be critical prime habitats. We analyzed historical spatiotemporal behavior since current patterns represent only a fraction of pre-Columbian ones. Given the limited knowledge, the first group (n = 6) in Argentina was radio-marked to examine spatial behavior. Historically, huemul resided year-round in winter ranges, while some migrated seasonally, some using grasslands >200 km east of their current presence, reaching the Atlantic. Moreover, huemul anatomy is adapted to open unforested habitats, also corroborated by spotless fawns. Extreme naivety towards humans resulted in early extirpation on many winter ranges—preferentially occupied by humans, resulting in refugee huemul on surrounding mountain summer ranges. Radio-marked huemul remained in small ranges with minimal altitudinal movements, as known from other subpopulations. However, these resident areas documented here are typical summer ranges as evidenced by past migrations, and current usage for livestock. The huemul is the only cervid known to use mountain summer ranges year-round in reaction to anthropogenic activities. Losing migratory traditions is a major threat, and may explain their presently prevalent skeletal diseases, reduced longevity, and lacking recolonizations for most remaining huemul subpopulations
The impact of conservation on the status of the world's vertebrates
Using data for 25,780 species categorized on the International Union for Conservation of Nature Red List, we present an assessment of the status of the world's vertebrates. One-fifth of species are classified as Threatened, and we show that this figure is increasing: On average, 52 species of mammals, birds, and amphibians move one category closer to extinction each year. However, this overall pattern conceals the impact of conservation successes, and we show that the rate of deterioration would have been at least one-fifth again as much in the absence of these. Nonetheless, current conservation efforts remain insufficient to offset the main drivers of biodiversity loss in these groups: agricultural expansion, logging, overexploitation, and invasive alien species