32 research outputs found

    Jaguar Densities across Human-Dominated Landscapes in Colombia: The Contribution of Unprotected Areas to Long Term Conservation

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    Large carnivores such as jaguars (Panthera onca) are species of conservation concern because they are suffering population declines and are keystone species in their ecosystems. Their large area requirements imply that unprotected and ever-increasing agricultural regions can be important habitats as they allow connectivity and dispersal among core protected areas. Yet information on jaguar densities across unprotected landscapes it is still scarce and crucially needed to assist management and range-wide conservation strategies. Our study provides the first jaguar density estimates of Colombia in agricultural regions which included cattle ranching, the main land use in the country, and oil palm cultivation, an increasing land use across the Neotropics. We used camera trapping across two agricultural landscapes located in the Magdalena River valley and in the Colombian llanos (47–53 stations respectively; >2000 trap nights at both sites) and classic and spatially explicit capture-recapture models with the sex of individuals as a covariate. Density estimates were 2.52±0.46–3.15±1.08 adults/100 km2 in the Magdalena valley, whereas 1.12±0.13–2.19±0.99 adults/100 km2 in the Colombian llanos, depending on analysis used. We suggest that jaguars are able to live across unprotected human-use areas and co-exist with agricultural landscapes including oil-palm plantations if natural areas and riparian habitats persist in the landscape and hunting of both jaguar and prey is limited. In the face of an expanding agriculture across the tropics we recommend land-use planning, adequate incentives, regulations, and good agricultural practices for range-wide jaguar connectivity and survival

    High Proportion of Male Faeces in Jaguar Populations

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    Faeces provide relevant biological information which includes, with the application of genetic techniques, the sex and identity of individuals that defecated, thus providing potentially useful data on the behaviour and ecology of individuals, as well as the dynamics and structure of populations. This paper presents estimates of the sex ratio of different felid species (jaguar, Panthera onca; puma, Puma concolor; and ocelot/margay, Leopardus pardalis/Leopardus wiedi) as observed in field collected faeces, and proposes several hypotheses that could explain the strikingly high proportion of faeces from male jaguars. The proportion of male and female faeces was estimated using a non-invasive faecal sampling method in 14 study areas in Mexico and Brazil. Faecal samples were genetically analysed to identify the species, the sex and the individual (the latter only for samples identified as belonging to jaguars). Considering the three species, 72.6% of faeces (n = 493) were from males; however, there were significant differences among them, with the proportion from males being higher for jaguars than for pumas and ocelots/margays. A male-bias was consistently observed in all study areas for jaguar faeces, but not for the other species. For jaguars the trend was the same when considering the number of individuals identified (n = 68), with an average of 4.2±0.56 faeces per male and 2.0±0.36 per female. The observed faecal marking patterns might be related to the behaviour of female jaguars directed toward protecting litters from males, and in both male and female pumas, to prevent interspecific aggressions from male jaguars. The hypothesis that there are effectively more males than females in jaguar populations cannot be discarded, which could be due to the fact that females are territorial and males are not, or a tendency for males to disperse into suboptimal areas for the species. © 2012 Palomares et al

    Density and spatio-temporal behaviour of Geoffroy's cats in a human-dominated landscape of southern Brazil

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    Geoffroy’s cat is a small Neotropical felid, seemingly abundant throughout most of its range and exhibiting considerable ecological plasticity. In Brazil, the species is restricted to the Pampas, one of the most threatened biomes in the country, where information on its ecology is scarce. Here we report the first assessments of its density, habitat selection, and activity patterns in Brazil. The study was conducted in human-dominated landscape at the extreme south of the country. Using Spatially Explicit Capture-Recapture (SECR) analyses, the estimated population density ranged from 34.54 (±13.51 SE), based on camera trap and radio-telemetry data, to 41.78 (±16.12 SE) individuals/100 km², based only on camera trap data. A Resource Selection Function (RSF) analysis showed that our study population selected sites with native forest and rivers, and avoided areas close to roads, which probably implies avoidance of human contact. Although we observed a slight increase in its nocturnal activity during spring-summer with respect to fall-winter, this population was predominantly nocturnal throughout the year. The use of grasslands and croplands (non-protected areas) was non-uniformly distributed through the hours of the day, whereas native forest was used more uniformly

    Pleistocene megafaunal interaction networks became more vulnerable after human arrival

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    The end of the Pleistocene was marked by the extinction of almost all large land mammals worldwide except in Africa. Although the debate on Pleistocene extinctions has focused on the roles of climate change and humans, the impact of perturbations depends on properties of ecological communities, such as species composition and the organization of ecological interactions. Here, we combined palaeoecological and ecological data, food-web models and community stability analysis to investigate if differences between Pleistocene and modern mammalian assemblages help us understand why the megafauna died out in the Americas while persisting in Africa. We show Pleistocene and modern assemblages share similar network topology, but differences in richness and body size distributions made Pleistocene communities significantly more vulnerable to the effects of human arrival. The structural changes promoted by humans in Pleistocene networks would have increased the likelihood of unstable dynamics, which may favour extinction cascades in communities facing extrinsic perturbations. Our findings suggest that the basic aspects of the organization of ecological communities may have played an important role in major extinction events in the past. Knowledge of community-level properties and their consequences to dynamics may be critical to understand past and future extinctions

    Results of long-term retrograde rectal cleansing in patients with constipation or fecal incontinence

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    Item does not contain fulltextBACKGROUND: The aim of the present study was to determine the success rate, quality of life and predictive factors of success associated with long-term rectal cleansing (RC) for defecatory disorders. METHODS: All patients who started RC between January 2010 and August 2014 in our referral hospital were sent questionnaires concerning actual RC, Short Form 36 Health Survey (SF-36), Fecal Incontinence Quality of Life (FI-QoL) and the Beck Depression Inventory (BDI). In addition, they were contacted in May and December 2015 for further follow-up information. RESULTS: Eighty-six patients were offered RC, and 60 patients (45 women, 15 men) started RC. Thirty-three (55 %) patients stopped RC after a median time of 6 months. Twenty-seven (45 %) continued for a median time of 12 months. Forty-three (72 %) patients responded to the questionnaires. SF-36 showed that patients still using RC had more energy and were less fatigued than patients who discontinued therapy. No significant difference was found between patients who stopped and continued RC concerning age, gender, defecation disturbance, underlying disorders, anorectal function, colon-transit time, FI-QoL or BDI-score. Twenty-three patients (38 %) were still performing RC after 21 months, 22 patients (37 %) after 28 months and 1 patient was lost to follow-up. CONCLUSIONS: RC is a moderately effective long-term alternative in patients who do not respond to medical therapy and biofeedback exercises. There is a high dropout rate in the first months, but a moderate rate of continuation in the period hereafter. No predictive factors for continuation were found in medical history or function tests. Those who continued RC performed better on the SF-36 subscale energy/fatigue
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