22 research outputs found

    Domestic dogs (canis familiaris) in atlantic forest fragments in rural and urban areas and their relationship with the surrounding human occupation

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    Orientador: Paulo Inacio de Knegt Lopez de PradoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: O cão doméstico tem atuado como espécie exótica invasora, perturbando e modificando ecossistemas nativos de diferentes maneiras. Porém, pouco se sabe sobre o tamanho da população de cães que habitam locais próximos a áreas de interesse ambiental e se isso pode influenciar a chance de entrada desses animais em tais áreas. Além disso, apesar de sua estreita ligação com a população humana, pouco se sabe sobre a relação desta com a população de cães. Sendo assim, o presente estudo teve como objetivos estimar o tamanho de populações de cães, em área urbana e rural próximas a fragmentos florestais, entender de que modo a população humana dessas áreas maneja seus cães e qual a freqüência de ocorrência de cães nos fragmentos florestais. Assim, foram feitas entrevistas com os residentes de modo a obter informações sobre o número de cães com dono e o regime de manejo dado a eles, censos de cães soltos nas áreas e foram montadas parcelas de areia dentro dos fragmentos, a distâncias crescentes da borda, para verificar a freqüência de ocorrência dos cães e se ela diferia da borda para o interior. Os resultados indicaram que ter cães é mais comum em área rural, bem como deixá-los soltos fora da propriedade. Apesar disso, o tamanho da população de cães é maior nas áreas urbanas estudadas, devido a grande densidade populacional humana. Também nessas áreas há cães sem dono, algo raro nas áreas rurais estudadas. O tamanho da população de cães no entorno não influencia a freqüência de ocorrência desses animais dentro dos fragmentos e em ambos os ambientes (rural e urbano), os cães parecem ser um efeito de borda nos fragmentos florestais. Apesar de serem pouco freqüentes a distâncias maiores da borda, esses animais foram marcadamente muito mais freqüentes que carnívoros silvestres, podendo ser mais um impacto importante causado pela presença humana nessas áreas. Assim, o efeito direto que os cães domésticos exercem sobre a fauna local é algo que ainda precisa ser estudado no BrasilAbstract: Domestic dogs (Canis familiaris) have been acting as invasive exotic species in many instances, disturbing and modifying natural ecosystems in many ways. Still, little is know about the dogs population size near areas of conservation interest and if that can influence dog¿s chance of using those areas. In addiction, despite their close relationship with humans, little is know about the people¿s attitudes towards the dog population. Thus, this study intends to estimate dog populations sizes in urban and rural areas near forest patches, to investigate the people¿s attitudes towards dogs in those areas and to quantify dog frequencies inside forest patches. For that purpose, questionnaires with local residents were conducted to obtain information about dogs¿ number and the owners¿ attitudes towards caring for their dogs. Censuses on the areas were conducted to estimate numbers of unrestricted and stray dogs. Scent-stations were installed inside the forest patches, at different distances from the edge, to evaluate the frequency of those animals and see if it differed between patches¿ edge and their interior. Having a dog is more common in the rural area, as well as keeping them unrestricted. Yet, dogs¿ population is larger in the urban areas studied, due to high human densities. Also, in those areas there are stray dogs, which is uncommon in the rural areas studied. The dogs¿ population size in the surroundings don¿t influence their presence inside the forest patches and in both landscapes (rural and urban), dogs seems to be an edge effect. Despite not being very common inside the patches other than in its edge, these animals seem to occur more frequently than wild carnivores. For that reason they can represent another important negative impact cause by the human presence in those areas. Domestic dogs¿ direct effects on wildlife still have to be studied in Brazil, nonetheless these potential impacts can be minored by preventing dogs from entering the forest patches. To do so, the residents¿ attitudes towards dogs, in the surrounding areas, are of extreme importanceMestradoEcologiaMestre em Ecologi

    The species-specific role of wildlife in the Amazonian food system

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    We examine ways in which the role of wild animals in the Amazonian food system may be socially differentiated and species-specific. We combine a hybrid framework of food choice preferences and theorizing on access to natural resources with fieldwork in Brazilian Amazon, where social and environmental challenges coalesce around the role of wildlife in feeding a growing urban population. Based on 798 household surveys across four towns, we found that consumption of, and taste preferences for, selected species of mammals, fishes, birds, and reptiles are related to variation in means of access (e.g., level of social trust - the basis of reciprocity and informal urban safety nets), and having rural cultural origins (marginal to migrants’ other socioeconomic differences). The likelihood of eating particular species was associated with taste preferences and household experiences of food insecurity. Hunting and fishing households consumed many wild species; it is unclear if they depend heavily on any in particular. Vulnerable species, including manatee, tortoise, and river turtle, were eaten mainly by relatively privileged households, and less so by other households (e.g., rural-urban migrants). Rural origins increased by 90% the likelihood of a strong wild meat preference, compared to other households. Evidently, wildlife consumption is a rural tradition that influences migrants’ dietary practices in towns, through the interplay of preferences, means of access, and context. Finally, severe and moderate food insecurity was associated with eating howler monkey and catfishes (barred and redtail) and not eating manatee and turtle. Hence, urban consumption of some, but not all, wild species is associated with household disadvantage and food insecurity. Amazonian town-dwellers consume many wild species, drawing on diverse means of access, which are species-specific and reflect social inequalities. Species-specific governance of wildlife consumption may help balance the risks of overharvesting against the well-being of Amazonia’s vulnerable town-dwellers

    Effects of habitat deterioration on the population genetics and conservation of the jaguar

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    Over the past century, human activities and their side effects have significantly threatened both ecosystems and resident species. Nevertheless, the genetic patterns of large felids that depend heavily on large and well-conserved continuous habitat remain poorly studied. Using the largest-ever contemporary genetic survey of wild jaguars (Panthera onca), we evaluated their genetic diversity and population structure in natural (Brazilian Amazon) and highly modified habitats (e.g. Cerrado, Caatinga) including those close to the northern (Yucatan, Mexico) and southern (Pantanal) edge of the species’ distribution range. Data from our set of microsatellites revealed a pronounced genetic structure, with four genetically differentiated geographic areas. Geographic distance was not the only factor influencing genetic differentiation through the jaguar range. Instead, we found evidence of the effects of habitat deterioration on genetic patterns: while the levels of genetic diversity in the Amazon forest, the largest continuum habitat for the species, are high and consistent with panmixia across large distances, genetic diversity near the edge of the species distribution has been reduced through population contractions. Mexican jaguar populations were highly differentiated from those in Brazil and genetically depauperated. An isolated population from the Caatinga showed the genetic effects of a recent demographic decline (within the last 20–30 years), which may reflect recent habitat degradation in the region. Our results demonstrate that the jaguar is highly sensitive to habitat fragmentation especially in human-dominated landscapes, and that in Brazil, the existing but limited genetic connectivity in the central protected areas should be maintained. These conclusions have important implications for the management of wide-ranging species with high dispersal and low population density. The restoration of ecological connectivity between populations over relatively large scales should be one of the main priorities for species conservation.Peer reviewe

    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

    Bushmeat hunting and consumption in Eastern Amazonia: drivers and effects on the perception of forest value

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    A extração de produtos florestais é uma estratégia de sustento importante para populações que vivem próximas a remanescentes de florestas tropicais. Entre estes produtos, a carne silvestre é fonte importante de proteína e renda monetária. A sobreçaca, no entanto, pode levar à extinção local de espécies, comprometendo a integridade das florestas tropicais e o sustento de populações humanas. Como consequência, pode também levar à diminuição do valor atribuído às florestas pelos moradores, incentivando a sua conversão a outras formas de uso da terra. Sabe-se que fatores econômicos, como renda monetária e riqueza, são determinantes importantes da caça e do consumo de carne silvestre. Porém, tem sido sugerido que o efeito destes indicadores econômicos dependa do contexto ambiental - em especial, a cobertura florestal, associada à disponibilidade de animais para caça e a distância ao centro urbano, associada ao acesso a outras fontes de renda e proteína - e do contexto cultural, em particular, a região de origem dos moradores. No entanto, estudos prévios não consideraram todos estes fatores simultaneamente. Além disso, pouco ainda se sabe sobre qual o valor atribuído às florestas por populações rurais e sua relação com a caça e o consumo de carne silvestre. Através de questionários estruturados aplicados por meio de entrevista à população rural de uma região extensa e heterogênea na Amazônia oriental, esta tese teve como objetivos investigar: (i) o efeito de fatores ambientais em maior escala como determinantes da caça e do consumo de carne silvestre (Capítulo 1); (ii) a importância relativa e as interações entre fatores em escalas distintas - econômicos, culturais e ambientais - na determinação da caça e do consumo de carne silvestre (Capítulo 2) e; (iii) se a caça e o consumo de carne silvestre, bem como o desmatamento, que pode comprometer esse recurso, estão associados à percepção do valor das florestas (Capítulo 3). No Capítulo 1, os resultados indicam que fatores ambientais são determinantes mais importantes da caça do que do consumo de carne silvestre, que é mais frequente que a caça, sugerindo a relevância do compartilhamento e/ou comércio como formas de obtenção de carne silvestre. Enquanto o consumo de carne de silvestre foi um pouco mais frequente em áreas remotas e mais florestadas, a caça foi mais frequente em áreas mais florestadas, mas também em áreas mais próximas a centros urbanos. Assim, os resultados sugerem que é improvável que a pressão de caça diminua com a crescente migração para áreas urbanas que hoje se observa na Amazônia. O Capítulo 2 traz evidências de que o consumo de carne silvestre, e principalmente a caça, dependem não só do contexto ambiental, mas também do cultural, e que os efeitos de indicadores econômicos dependem de fatores ambientais. A caça e o consumo de carne silvestre foram mais frequentes nas famílias de origem na região Amazônica, entre aqueles que dependem mais de atividades de subsistência, e ambos aumentaram com a renda monetária em áreas próximas a centros urbanos e/ou menos florestadas, mas diminuíram com a renda monetária em áreas remotas e/ou florestadas. Isto sugere que o sucesso de intervenções econômicas que visem tanto à redução da pobreza quanto à conservação da biodiversidade depende do contexto ambiental, e é muito mais provável em áreas mais florestadas e remotas. Os resultados do Capítulo 3 indicam que a quantidade de carne silvestre consumida influencia positivamente a percepção do valor utilitário da floresta, enquanto que a quantidade de florestas remanescentes no entorno influencia positivamente a percepção de seu valor intrínseco. Assim, para além de estratégias que visem o bem-estar humano via incentivos econômicos, há oportunidade para iniciativas que considerem outros aspectos do bem-estar associados aos serviços providos pela floresta - sejam recursos como a carne silvestre ou benefícios culturais e estéticos. Ao mesmo tempo, os resultados apontam o potencial de um perigoso ciclo de desvalorização da floresta, em que o desmatamento leva a diminuição da percepção do seu valor, que, por sua vez, pode agravar o desmatamento, indicando a urgência de investimentos em iniciativas de conservação nas paisagens mais alteradasThe extraction of forest products is an important livelihood strategy for human populations living in and around tropical forest remnants. Among these products, bushmeat is an important source of protein and monetary income. However, overhunting can lead to local species extinction, compromising the integrity of tropical forests and the livelihoods of human populations. As a consequence, it can also lead to a decrease in the value local people attribute to forests, further promoting land conversion. It is well known that economic factors, such as monetary income and asset-wealth, are important drivers of bushmeat hunting and consumption. However, it has been suggested that the effect of economic factors depend on the environmental context - especially forest cover, associated with game availability, and distance to urban centers, associated with alternative sources of protein and income - and on the cultural context, particularly the region of origin of residents. Nevertheless, previous studies did not consider all these factors simultaneously. In addition, little is known about the value attributed to forests by rural populations and its association with bushmeat hunting and consumption. Using questionnaire-based interviews with the rural population of a wide heterogeneous region in eastern Amazonia, this thesis aimed at investigating (i) the effects of large-scale environmental factors as drivers of bushmeat hunting and consumption (Chapter 1); (ii) the relative importance and interactions between factors at different scales - economic, cultural and environmental - in driving bushmeat hunting and consumption (Chapter 2) and; (iii) whether bushmeat hunting and consumption, as well as deforestation, which may compromise this resource, are associated with the perception of forest values (Chapter 3). In Chapter 1, the results indicate that environmental factors are more important drivers of hunting than of bushmeat consumption, which is widespread, suggesting significant bushmeat sharing and/ or trading. While bushmeat consumption was slightly more likely in remote and more forested areas, hunting was more likely in more forested areas but also in areas closer to urban centers. These results suggest that hunting pressure is unlikely to decrease with the increasing migration to urban areas nowadays observed in the Amazon. Chapter 2 brings evidences that bushmeat consumption, and especially hunting, depend not only on the environmental context but also on the cultural context, and that the effects of economic variables depend on environmental factors. Bushmeat hunting and consumption were more likely in households with Amazonian origin, with greater reliance on subsistence activities and both increased with monetary income in less remote and/or less forested areas, but decreased with monetary income in more remote and/or more forested areas. This result suggests that the success of economic interventions aiming at both poverty alleviation and biodiversity conservation depend on the environmental context, and is more likely in more forested and remote areas. The results of Chapter 3 indicate that the amount of consumed bushmeat positively influences the perception of forest instrumental value, while forest cover in the surroundings positively influences the perception of forest intrinsic value. These results suggest that, beyond strategies that aim at human well-being through economic incentives, there is opportunity for initiatives that consider other aspects of well-being associated with services provided by forests - whether resources such as bushmeat or cultural and aesthetic benefits. At the same time, the results suggest the potential for a dangerous reinforcing cycle of forest depreciation, in which deforestation erodes perceptions of forest values, which may in turn facilitate further deforestation, indicating the urgent need to invest in conservation initiatives in more altered landscape

    Individual values attributed to forests in Amazonia

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    Data set of the values atrributed to the forest (material and non-material) for the enterviewees in the study. <br><br>This data set was used to:<br><br>1. calculate the association between independent variables (hunting, consumption and control variables) and the material value of forests (using forest_value_all_hh_heads table).  <br><br>2. calculate the association between independent variables (forest cover, visits to forest and control variables) and the non-material value of forests (using forest_value_heads_that_visit_forest table).<br><br>3. Scale evaluation (using forest values statments table).   <br

    Forest cover and social relations are more important than economic factors in driving hunting and bushmeat consumption in post-frontier Amazonia

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    Identifying the economic drivers of hunting and bushmeat consumption is crucial for understanding whether economic growth in tropical forest regions can foster poverty alleviation and biodiversity conservation. However, studies investigating those drivers have drawn contrasting conclusions. Some authors attribute inconsistent findings to heterogeneous spatial and environmental contexts, yet other studies indicate that social factors may predominate over economical determinants. Here, we investigate bushmeat hunting and consumption by analyzing the relative importance of household-scale economic factors in diverse spatial and environmental contexts. We surveyed 240 households distributed across twenty diverse rural landscapes in a post-frontier region in Brazilian Amazonia. Our results show that hunting is more likely in locations with higher forest cover, where game availability is expected to be higher. In contrast, bushmeat consumption is widespread even in deforested landscapes near to urban centers. However, we find no evidence that household-scale economic factors determine variation in rural bushmeat consumption, regardless of spatial or environmental context. Consequently, we infer that future growth in income or wealth would be unlikely to significantly change patterns of bushmeat hunting and consumption. Instead, we find that eating bushmeat is mainly dependent on the hunting of relatively common species for subsistence and food sharing, rather than through market exchange. This demonstrates an important informal economy maintained by social relations. Work is needed to evaluate the sustainability of hunting these small to medium-sized species given they evidently provide useful ecosystem service to poor households and are likely to support social relations in rural Amazonia
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