34 research outputs found

    Seasonal Migration of Sika Deer in the Oku-Chichibu Mountains, Central Japan

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    Movements and seasonal home ranges of 6 GPS collared sika deer were investigated at the Oku-Chichibu Mountains, central Honshu, from April 2009 to March 2010. All deer migrated between discrete summer and winter home ranges. The linear migration distance ranged from 2.5 to 31.9 km. Mean elevation during the summer and the winter ranged from 980 to 1,782 m, and from 1,204 to 1,723 m, respectively. Two deer were upward migrants and 4 deer were downward migrants. Taking into consideration of the relatively small snow accumulation in the summer home range, the possibility of autumn migration to avoid deep snow is low. The percentage of steep slope in the winter home range was higher than that in the summer. Bamboo grass was not found in the summer home range, but was predominant in the winter home range. Road density decreased in the winter home range compared to the summer. Only 2 out of 6 deer stayed mainly in the wildlife protection area during the winter. Our results indicate that the autumn migration was affected by winter forage and human disturbance, thereby assured the survival of the deer during winter.ArticleMAMMAL STUDY. 37(2):127-137 (2012)journal articl

    Movement patterns of forest elephants (Loxodonta cyclotis Matschie, 1900) in the Odzala-Kokoua National Park, Republic of Congo

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    [Otros] Les Ă©lĂ©phants de forĂȘt d'Afrique (Loxodonta cyclotis Matschie, 1900) sont des ingĂ©nieurs en Ă©cologie qui jouent un rĂŽle fondamental dans la dynamique de la vĂ©gĂ©tation. L'espĂšce constitue une prĂ©occupation immĂ©diate pour la conservation, mais elle est relativement peu Ă©tudiĂ©e. Pour combler cette lacune de connaissances, nous avons Ă©tudiĂ© les facteurs de dĂ©placements quotidiens (dĂ©placements linĂ©aires) des Ă©lĂ©phants de forĂȘt Âż caractĂ©risĂ©s par un ensemble de variables gĂ©ographiques, mĂ©tĂ©orologiques et anthropiques Âż dans le Parc National d'OdzalaÂżKokoua, en RĂ©publique du Congo. ConcrĂštement, nous avons utilisĂ© la forĂȘt d'arbres dĂ©cisionnels pour modĂ©liser et dĂ©mĂȘler les principaux facteurs environnementaux rĂ©gissant les dĂ©placements de six Ă©lĂ©phants de forĂȘt, Ă©quipĂ©s de colliers GPS et suivis pendant 16 mois. Les rĂ©sultats ont montrĂ© que les femelles se dĂ©plaçaient plus loin que les mĂąles, tandis que la prĂ©sence de routes ou d¿établissements humains perturbait le comportement des Ă©lĂ©phants, ce qui accĂ©lĂ©rait les dĂ©placements. Les Ă©lĂ©phants de forĂȘt se dĂ©plaçaient plus rapidement dans les cours dÂżeau et dans les forĂȘts dont le sousÂżbois Ă©tait dominĂ© par les forĂȘts de Marantaceae et les bais, mais se dĂ©plaçait plus lentement dans les savanes. Enfin, les zones inondables Âż characterisĂ©es par lÂżaltitude et les prĂ©cipitations accumulĂ©es Âż et les tempĂ©ratures plus Ă©levĂ©es empĂȘchaient des dĂ©placements plus longs. Nous espĂ©rons que ces rĂ©sultats amĂ©lioreront les connaissances sur les mouvements des espĂšces Ă  travers diffĂ©rents habitats, ce qui serait bĂ©nĂ©fique pour la gestion de leur conservation.[EN] African forest elephants (Loxodonta cyclotis Matschie, 1900) are ecological engineers that play a fundamental role in vegetation dynamics. The species is of immediate conservation concern, yet it is relatively understudied. To narrow this knowledge gap, we studied the drivers of daily movement patterns (linear displacements) of forest elephantsÂżcharacterised by a set of geographical, meteorological and anthropogenic variablesÂżin the OdzalaÂżKokoua National Park, Republic of Congo. Explicitly, we used conditional random forest to model and disentangle the main environmental factors governing the displacements of six forest elephants,fitted with GPS collars and tracked over 16 months. Results indicated that females moved further distances than males, while the presence of roads or human settlements disrupted elephant behaviour resulting in faster displacements. Forest elephants moved faster along watercourses and through forest with understory dominated by Marantaceae forests and bais, but moved slower in savannahs. Finally, floodÂżprone areasÂżdescribed by elevation and accumulated precipitationÂżand higher temperatures prevented longer displacements. We expect these results to improve the knowledge on the species movements through different habitats, which would benefit its conservation management.The fieldwork was financed by African Parks. We are grateful to the Congolese wildlife authorities (MinistĂšre de l'Économie ForestiĂšre et de l'Environnement) for the permission to carry out this study, and we are deeply indebted to the director of the OKNP and to the conservation, wildlife monitoring and research manager, Erik Marav, respectively, for their continued support during our study. We are particularly grateful to Dr. Mike Kock, veterinarian, for collaring the elephants and to the field tracking team. We are also grateful to SĂ©an Cahill for the useful comments and English correction that helped improve this manuscript. The authors of the present study certify that they have no affiliations with or involvement in any organisation or entity with any financial or nonfinancial interest in the subject matter or materials discussed in this manuscript.Molina-Vacas, G.; Muñoz-Mas, R.; Martinez-Capel, F.; Rodriguez-Teijeiro, JD.; Le Fohlic, G. (2019). Movement patterns of forest elephants (Loxodonta cyclotis Matschie, 1900) in the Odzala-Kokoua National Park, Republic of Congo. African Journal of Ecology. 58:23-33. https://doi.org/10.1111/aje.12695S233358Arlot, S., & Celisse, A. (2010). A survey of cross-validation procedures for model selection. Statistics Surveys, 4(0), 40-79. doi:10.1214/09-ss054Bermejo, M. (1999). Status and conservation of primates in Odzala National Park, Republic of the Congo. Oryx, 33(4), 323-331. doi:10.1046/j.1365-3008.1999.00081.xBirkett, P. J., Vanak, A. T., Muggeo, V. M. R., Ferreira, S. M., & Slotow, R. (2012). Animal Perception of Seasonal Thresholds: Changes in Elephant Movement in Relation to Rainfall Patterns. PLoS ONE, 7(6), e38363. doi:10.1371/journal.pone.0038363Blake, S., Deem, S. L., Strindberg, S., Maisels, F., Momont, L., Isia, I.-B., 
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    Can forest management based on natural disturbances maintain ecological resilience?

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    Given the increasingly global stresses on forests, many ecologists argue that managers must maintain ecological resilience: the capacity of ecosystems to absorb disturbances without undergoing fundamental change. In this review we ask: Can the emerging paradigm of natural-disturbance-based management (NDBM) maintain ecological resilience in managed forests? Applying resilience theory requires careful articulation of the ecosystem state under consideration, the disturbances and stresses that affect the persistence of possible alternative states, and the spatial and temporal scales of management relevance. Implementing NDBM while maintaining resilience means recognizing that (i) biodiversity is important for long-term ecosystem persistence, (ii) natural disturbances play a critical role as a generator of structural and compositional heterogeneity at multiple scales, and (iii) traditional management tends to produce forests more homogeneous than those disturbed naturally and increases the likelihood of unexpected catastrophic change by constraining variation of key environmental processes. NDBM may maintain resilience if silvicultural strategies retain the structures and processes that perpetuate desired states while reducing those that enhance resilience of undesirable states. Such strategies require an understanding of harvesting impacts on slow ecosystem processes, such as seed-bank or nutrient dynamics, which in the long term can lead to ecological surprises by altering the forest's capacity to reorganize after disturbance

    A Low-Cost GPS GSM/GPRS Telemetry System: Performance in Stationary Field Tests and Preliminary Data on Wild Otters (Lutra lutra)

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    Background: Despite the increasing worldwide use of global positioning system (GPS) telemetry in wildlife research, it has never been tested on any freshwater diving animal or in the peculiar conditions of the riparian habitat, despite this latter being one of the most important habitat types for many animal taxa. Moreover, in most cases, the GPS devices used have been commercial and expensive, limiting their use in low-budget projects. Methodology/Principal Findings: We have developed a low-cost, easily constructed GPS GSM/GPRS (Global System for Mobile Communications/General Packet Radio Service) and examined its performance in stationary tests, by assessing the influence of different habitat types, including the riparian, as well as water submersion and certain climatic and environmental variables on GPS fix-success rate and accuracy. We then tested the GPS on wild diving animals, applying it, for the first time, to an otter species (Lutra lutra). The rate of locations acquired during the stationary tests reached 63.2%, with an average location error of 8.94 m (SD = 8.55). GPS performance in riparian habitats was principally affected by water submersion and secondarily by GPS inclination and position within the riverbed. Temporal and spatial correlations of location estimates accounted for some variation in the data sets. GPS-tagged otters also provided accurate locations and an even higher GPS fix-success rate (68.2%). Conclusions/Significance: Our results suggest that GPS telemetry is reliably applicable to riparian and even divin

    Linkage analysis of obesity phenotypes in pre- and post-menopausal women from a United States mid-western population

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    <p>Abstract</p> <p>Background</p> <p>Obesity has a strong genetic influence, with some variants showing stronger associations among women than men. Women are also more likely to distribute weight in the abdomen following menopause. We investigated whether genetic loci link with obesity-related phenotypes differently by menopausal status.</p> <p>Methods</p> <p>We performed univariate and bivariate linkage analysis for the phenotypes of body mass index (BMI), waist (W) and hip (H) circumferences (WC, HC), and WH ratio (WHR) separately among 172 pre-menopausal and 405 post-menopausal women from 90 multigenerational families using a genome scan with 403 microsatellite markers. Bivariate analysis used pair-wise combinations of obesity phenotypes to detect linkage at loci with pleiotropic effects for genetically correlated traits. BMI was adjusted in models of WC, HC and WHR.</p> <p>Results</p> <p>Pre-menopausal women, compared to post-menopausal women, had higher heritability for BMI (<it>h</it><sup>2 </sup>= 94% versus <it>h</it><sup>2 </sup>= 39%, respectively) and for HC (<it>h</it><sup>2 </sup>= 99% versus <it>h</it><sup>2 </sup>= 43%, respectively), and lower heritability for WC (<it>h</it><sup>2 </sup>= 29% versus <it>h</it><sup>2 </sup>= 61%, respectively) and for WHR (<it>h</it><sup>2 </sup>= 39% versus <it>h</it><sup>2 </sup>= 57%, respectively). Among pre-menopausal women, the strongest evidence for linkage was for the combination of BMI and HC traits at 3p26 (bivariate LOD = 3.65) and at 13q13-q14 (bivariate LOD = 3.59). Among post-menopausal women, the highest level of evidence for genetic linkage was for HC at 4p15.3 (univariate LOD = 2.70) and 14q13 (univariate LOD = 2.51). WC was not clearly linked to any locus.</p> <p>Conclusions</p> <p>These results support a genetic basis for fat deposition that differs by menopausal status, and suggest that the same loci encode genes that influence general obesity (BMI) and HC, specifically, among pre-menopausal women. However, lower heritability among pre-menopausal women for WC and WHR suggests that pre-menopausal waist girth may be influenced to a greater extent by controllable environmental factors than post-menopausal waist girth. Possibly, targeted interventions for weight control among pre-menopausal women may prevent or attenuate post-menopausal abdominal weight deposition.</p

    The influence of expectation on spinal manipulation induced hypoalgesia: An experimental study in normal subjects

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    <p>Abstract</p> <p>Background</p> <p>The mechanisms thorough which spinal manipulative therapy (SMT) exerts clinical effects are not established. A prior study has suggested a dorsal horn modulated effect; however, the role of subject expectation was not considered. The purpose of the current study was to determine the effect of subject expectation on hypoalgesia associated with SMT.</p> <p>Methods</p> <p>Sixty healthy subjects agreed to participate and underwent quantitative sensory testing (QST) to their leg and low back. Next, participants were randomly assigned to receive a positive, negative, or neutral expectation instructional set regarding the effects of a specific SMT technique on pain perception. Following the instructional set, all subjects received SMT and underwent repeat QST.</p> <p>Results</p> <p>No interaction (p = 0.38) between group assignment and pain response was present in the lower extremity following SMT; however, a main effect (p < 0.01) for hypoalgesia was present. A significant interaction was present between change in pain perception and group assignment in the low back (p = 0.01) with participants receiving a negative expectation instructional set demonstrating significant hyperalgesia (p < 0.01).</p> <p>Conclusion</p> <p>The current study replicates prior findings of c- fiber mediated hypoalgesia in the lower extremity following SMT and this occurred regardless of expectation. A significant increase in pain perception occurred following SMT in the low back of participants receiving negative expectation suggesting a potential influence of expectation on SMT induced hypoalgesia in the body area to which the expectation is directed.</p

    Estrogens protect male mice from obesity complications and influence glucocorticoid metabolism

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    BACKGROUND: Although the prevalence of obesity is higher among women than men, they are somewhat protected from the associated cardiometabolic consequences. The increase in cardiovascular disease risk seen after the menopause suggests a role for estrogens. There is also growing evidence for the importance of estrogen on body fat and metabolism in males. We hypothesized that that estrogen administration would ameliorate the adverse effects of obesity on metabolic parameters in males. METHODS: Male and female C57Bl/6 mice were fed control or obesogenic (DIO) diets from 5 weeks of age until adulthood. Glucose tolerance testing was performed at 13 weeks of age. Mice were killed at 15 weeks of age and liver and adipose tissue were collected for analysis of gene expression. A second cohort of male mice underwent the same experimental design with the addition of estradiol pellet implantation or sham surgery at 6 weeks. RESULTS: DIO males had greater mesenteric adipose deposition and more severe increases in plasma glucose, insulin and lipids than females. Treatment of males with estradiol from 6 weeks of age prevented DIO-induced increases in adipose tissue mass and alterations in glucose–insulin homeostasis. We also identified sex differences in the transcript levels and activity of hepatic and adipose glucocorticoid metabolizing enzymes. Estrogen treatment feminized the pattern of DIO-induced changes in glucocorticoid metabolism, rendering males similar to females. CONCLUSIONS: Thus, DIO induces sex-specific changes in glucose–insulin homeostasis, which are ameliorated in males treated with estrogen, highlighting the importance of sex steroids in metabolism. Given that altered peripheral glucocorticoid metabolism has been observed in rodent and human obesity, our results also suggest that sexually dimorphic expression and activity of glucocorticoid metabolizing enzymes may have a role in the differential metabolic responses to obesity in males and females

    Data from: From steps to home range formation: species-specific movement upscaling among sympatric ungulates

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    Animals move to interact with the environment in order to find food resources and cover. Intrinsic characteristics affecting feeding and antipredatory strategies likely shape variation in movement patterns and home range formation between individuals, populations and species. Browsing herbivores selectively forage on patchily distributed resources in areas with more canopy cover, whereas mixed feeders and grazers feed on more open grasslands and tend to aggregate as an antipredatory strategy. We therefore predicted that at small temporal scales, browsers will show greater net displacements (i.e. typical of searching patterns) than mixed feeders or grazers; but at larger temporal scales, we expect the opposite pattern, since gregarious species will need to use larger areas to feed the whole herd. We also predicted that the feeding/antipredatory strategy will determine the behavioural responses to other environmental factors. To test this, we compared spatial movement patterns at multiple scales (from 20-min intervals to annual home ranges) of three sympatric, similar-sized, alpine ungulates which differ in their feeding/antipredatory strategy: roe deer (solitary browsers), mouflon (gregarious grazers) and chamois (intermediate feeders in smaller groups). We used location data from GPS-collared females of the three species in the French Alps. As predicted, we found that multi-scale spatial patterns depended on the feeding/antipredatory strategy. Browsers foraged within smaller range areas, searching back and forth. Mixed feeders and, especially, grazers covered larger areas, presumably to satisfy herd needs. The feeding/antipredatory strategies also determined the interspecific variability in behavioural responses to factors such as maternal status, weather, habitat type or human disturbance, supporting our hypothesis. Exploring interspecific variability, we showed how movement behaviour and home range formation vary substantially, even among species within the same guild. This mechanism might be important to maintain intra-guild multi-species associations and increase biodiversity, through contributing to niche segregation and, thus, coexistence
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