Natural mortality patterns in a population of southern Argentina huemul (Hippocamelus bisulcus), an endangered Andean cervid

The huemul (Hippocamelus bisulcus), an endangered deer living in the Andes of southern South America, numbers 600-700 in Argentina, from at least 63 fragmented subpopulations. Very limited information exists on most populations, but there are indications that the distribution and population sizes continue to diminish, possibly through reduced reproductive rates, elevated mortality rates or both. This is the first analysis of the population ecology of a subpopulation in Argentina, made possible through the only existing compilation of numerous remains of dead huemul (n = 19). Surveys were conducted between 1993 and 1999 to locate and collect remains, which were found concentrated at lower elevations. The sex ratio of adults and subadults (n = 12) was 1:1, but could not be determined for fawns. Clear signs of predation was found in 37% of all deer: 50% among calves, 50% among subadults and 31% among adults. These signs occurred in 29% of adult females and 50% of adult males. Deaths occurred during winter as judged by the state of the male skulls, which indicated the phase of the antler cycle. Femur fat content of 3 deer averaged 93%. Predation signs frequently were clearly from puma (Puma concolor), which is the only natural predator of huemul. The high predation rate, high marrow fat content and no indications of deaths resulting from disease corroborate the pristine state of the of mature lenga (Nothofagus pumilio) forest. The area with a concentration of huemul carcasses appears to be the huemul's major winter habitat.Fil: Smith Fluck, Anne M.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Departamento de Ecología; ArgentinaFil: Fluck, Werner Thomas. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Comahue. Centro Regional Universitario Bariloche. Departamento de Ecología; Argentin

Severe dental fluorosis in juvenile deer linked to a recent volcanic eruption in Patagonia

The Puyehue-Cordon Caulle volcanic eruption deposited large amounts of tephra (ashes) in over 7.5 million ha of Argentina in June of 2011. Tephra were considered chemically innoxious based on water leachates, surface water fluoride levels determined to be safe, and livestock losses attributable to inanition and excessive tooth wear. To evaluate effects on wild ungulates, we sampled wild red deer (Cervus elaphus) at 100 km from the volcanic eruption in Sept-Oct 2012. Here we show that these tephra caused severe dental fluorosis, with bone fluoride levels reaching up to 3720 ppm. Among subadults, tephra caused pathological development of newly emerging teeth typical of fluorosis, including enamel hypoplasia, breakages, pitting, mottling, and extremely rapid ablation of entire crowns down to underlying pulp cavities. The loss of teeth functionality affected physical condition and none of the subadults were able to conceive. Susceptibility to fluorosis among these herbivores likely resides in ruminant food processing: a) mastication and tephra size reduction, b) thorough and repeated mixing with alkaline saliva, c) water-soluble extraction in the rumen, and d) extraction in the acidic abomasum. Although initial analyses of water and tephra was interpreted not to present a concern, ruminants as a major component of this ecosystem are shown to be highly susceptible to fluorosis, with average bone level increasing over 36-fold during the first 15.5 months of exposure to tephra. This is the first report of fluorosis in wild ungulates from volcanic eruptions. The described impact will reverberate through several aspects of the ecology of the deer, including effects on population dynamics, morbidity, predation susceptibility, as well as other components of the ecosystem like the scavenger and plant communities. We also anticipate further impact on livestock production systems, yet as of now, existence of fluorosis has not been recognized.Fil: Fluck, Werner Thomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata; Argentina. University Basel. Swiss Tropical and Public Health Institute; Suiza. DeerLab; ArgentinaFil: Smith Fluck, Jo Anne M.. DeerLab; Argentin

Marcando con radio collar un grupo del amenazado huemul patagónico por primera vez en Argentina

En Argentina quedan 350-500 huemules en peligro de extinción. Se marcaron huemules con radio-collares durante 6 días de invierno. El encuentro de un huemul cada día promedió 93 minutos (17 grupos, 37 individuos). El período de tiempo desde la detección hasta la inmovilización promedió 46 minutos; la distancia de tiro promedió 15.7 m; y desde la inmovilización hasta recuperación promedió 45.5 minutos. Se realizaron 10 intentos de captura, de los cuales seis fueron exitosos. Comparado con la única radio-marcación anterior en Argentina, esta operación requirió 96.5% menos días-hombre/animal. De los huemules marcados, 86% presentaban patologías clínicas, posiblemente por estar restringidos a áreas marginales o sumideros, es decir, trampas ecológicas. Esta operación permitió marcar por primera vez un macho y un grupo de seis huemules en Argentina.In Argentina, 350-500 endangered huemul remain. Huemul were radio-collared in Chubut during six winter days. Encountering huemul each day averaged 93 minutes (17 groups, 37 individuals). Spotting until darting an animal averaged 46 minutes; darting distance averaged 15.7 m; and darting until recovery averaged 45.5 minutes. Ten capture attempts were made, of which six were successful. Compared to the only huemul previous radio-collared in Argentina (2016), the present operation required 96.5% less man-days/animal. Of marked huemul, 86% presented clinical pathologies, best explained by restriction to marginal if not sink areas, or ecological traps. This operation allowed the first-ever marking of huemul bucks in Argentina, and a group of six huemul.Fil: Fluck, Werner Thomas. Administración de Parques Nacionales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Basilea; SuizaFil: Smith Flueck, Jo Anne M.. Universidad Nacional del Comahue; Argentin

Huemul heresies: Beliefs in search of supporting data. 2. Biological and ecological considerations

Scarce information from remnant huemul (Hippocamelus bisulcus) populations in marginal habitats can lead to erroneous interpretations of the species' natural history, such as assumptions of being a highly inflexible species. We evaluated discrepancies between historical accounts and recent interpretations regarding biological and ecological traits to better understand factors preventing recovery of highly endangered huemul. Early information supports the theory that huemul are currently living under suboptimal conditions. We find variability to be the norm for huemul, as with other cervids, in regard to antler characteristics, group size and density, sexual segregation, and social and feeding behaviours. No evidence supports competition and disease from livestock or red deer as having caused declines or preventing recovery. Instead, livestock management, particularly presence of people and dogs, creates incompatibilities. Where red deer are sympatric with huemul, red deer are outnumbered by livestock by 2100%, and being regularly inspected at slaughter, livestock provide a good proxy for diseases afflicting red deer. Inadequate antipredator responses due to evolutionary absence of cursorial predators are unsupported as several Canis species coexisted with huemul, overlapping with dogs that arrived with Paleoindians. Three populations have increased despite high predator density. Age at maturity for huemul is 1 year, with evidence that fawns may also breed. Reported twinning needs confirmation, but occurs in congeneric taruca (H. antisensis) and other Odocoilines, and huemul frequently raise fawns successfully every year; life cycle calculations should apply these parameters. Like taruca, dominance group breeding systems have been described repeatedly. Although huemul bucks were recently claimed unique by displaying territoriality year-round, data do not support such behaviour. Two sole dispersal records (8 and 15.5 km) are unlikely to represent maximum dispersal capacity and do not support barriers assumed from few kilometres of unsuitable habitat. Huemul using 500 ha could predictably disperse up to 90 km, well within the ranges of other cervids. Mistakenly assuming barriers and underestimating reproductive capacity may distract from discovering the factors affecting recolonisations. Sustained recovery may depend on re-establishing source populations on more productive habitats, guided by zooarcheological and historical data.Fil: Fluck, Werner Thomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad de Basilea; Suiza. Universidad Atlantida Argentina; Argentina. Fundación Bariloche; ArgentinaFil: Smith-Flueck, Jo Anne M.. Universidad Atlantida Argentina; Argentin

Huemul heresies: Beliefs in search of supporting data. 1. Historical and zooarcheological considerations

Patagonian huemul (Hippocamelus bisulcus) was eliminated from many former ranges before arrival of early explorers who already acknowledged its rareness. Considering huemul analogous to ungulates in mountains back home, huemul was called mountain deer, which is repeatedly cited without validation and remains the orthodox interpretation. Yet other species considered analogous also use lowlands, flatlands, deserts and grasslands, and the only congeneric, H. antisensis, uses habitat with high affinity to Patagonian grasslands. Recent comparative analyses of the post-cranial morphology show that huemul cannot be associated with rock-climbing species, but falls within ranges of other cervids. Interpretations of past human utilisation rely on one study of economic anatomy and bone remains, frequently concluding that huemul was unimportant to hunter-gatherers. However, considering only bone fat and omitting easily removable fat is erroneous. Total energy of deer in autumnwinter partitions into 53% as fat and hunter-gatherers elsewhere focussed on deer during the peak fat cycle, using all easily removable fat (1200% more energy than in bones) and consuming fat and marrow while butchering. Natives are likely to have influenced huemul distribution and density in winter ranges due to high incentives (fat) and easiness to kill. Sparse evidence is likely the result of surveys in Patagonia having been biased towards caves, leaving out transient movements and camps. Generalist cervids passed the Panama land-bridge filter to reach South America. Considering paleoclimate, Hippocamelus dispersed east of the Andes, pushed by glaciations even to north-eastern Brazil. Hippocamelus would reach and cross Andes only after deglaciations. As a mixed feeder, huemul utilised Patagonian steppe. Hunter-gatherers arrived after the last glaciation and influenced the local distribution of Hippocamelus, especially in northern and central Chile, after early adoption of an agricultural lifestyle. Introduction of horses converted native economies through adoption of an equestrian lifestyle and arrival of millions of introduced livestock, which thus affected early writings. Only few records indicate the presence of large groups of huemul far from forests, and substantial killings. Human-caused range contractions of northern ungulates affected mainly losses at low elevations and most species persisted in the marginal periphery, including high-elevation refuges. Paleoecology, zoogeography and land-use history in southern South America indicate that mountain huemul is a secondary relict created by impacts of post-Columbian colonisation. We caution against the rigid application of modern huemul habitats in interpreting past habitat use and huemul ecology, and simply considering the few extra-Andean accounts as abnormal outliers.Fil: Fluck, Werner Thomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad de Basilea; Suiza. Universidad Atlantida Argentina; Argentina. Fundación Bariloche; ArgentinaFil: Smith-Flueck, Jo Anne M.. Universidad Atlantida Argentina; Argentin

Comet and close-approach asteroid mission study. volume 1- summary report final report

Comet and close-approach asteroid mission stud