Floodplain areas comprise some 30% of the area in the Amazon, but are currently under severe anthropogenic threat. Across the Amazon Basin, forest-dwelling non-volant mammals play crucial roles in maintaining the integrity of forest functionality, yet have been poorly studied in fluvial island forests. Mammal assemblages may be affected by edaphic characteristics that operate indirectly via food nutritional quality, by patch attributes, and/or can be modulated by anthropogenic disturbances. Here, we conducted systematic and quantitative mammal surveys across fluvial islands of an Amazonian archipelago, to assess the influence of edaphic factors (soil fertility), island attributes (island area and degree of isolation) and anthropogenic characteristics (distance from human settlement and logging) on the patterns of mammal species composition and richness. On 28 islands, we conducted spoor surveys and deployed 49 camera traps (total effort of 2940 camera trap-days). Subsequently, we performed multiple regression analysis to investigate the influence of environmental and anthropogenic predictors on mammal species richness, while dbRDA (distance-based redundancy analysis) was used for species composition. We found that mammal species richness was positively correlated with soil fertility, and in combination with anthropogenic characteristics, both variables affected the species assemblage composition. In particular, smaller species were found across a variety of levels of soil fertility and anthropogenic disturbances, while larger mammals were mostly recorded at sites with higher soil fertility and low levels of anthropogenic disturbances. Understanding the contribution of environmental and anthropogenic characteristics to the observed mammalian species richness and assemblage composition patterns will help optimise management and conservation efforts on Amazonian fluvial islands. In particular, we suggest enforcing hunting and logging restrictions within fluvial islands through surveillance activities, especially in more fertile islands.
Mammals can influence ecosystem functioning through essential ecologicalprocesses. In patchy landscapes, mammalian diversity can be correlated with ecosystem productivity through its effect on resource availability. However, mammals comprise species with contrasting habitat use and requirements, and it is unknown whether the diversity-productivity relationship changes as a function of the mammal species' traits. 2. We use meta-analytical techniques to quantify the effect and assess whether mammal species richness and abundance correlates positively with productivity. Further, we assess whether the diversity-productivity relationship is influenced by the species' body mass (<1 kg: small, and >1 kg: large, and mixed small and large), the vertical strata explored by the species (terrestrial, arboreal, and mixed terrestrial and arboreal species), and the species' feeding guild (herbivore, omnivore, insectivore, and mixed feeding guilds). 3. In total, 53 studies fitted the eligibility criteria worldwide, comprising 285 different effect sizes representing the magnitude of the mammal diversityproductivity relationship in six biogeographical realms. Ecosystem productivity was quantified with various surrogate variables, such as soil nutrients, annual rainfall, above-ground production, evapotranspiration, net primary production, plant cover, and elevation. 4. The relationships between productivity measures and both mammal species richness and abundance were significant and positive. Mammal diversity
<p>Em geral, animais resgatados passam um período em cativeiro para avaliação da condição física e capacidade de sobrevivência antes de retornarem a natureza. Durante este período, os animais devem ser estimulados através de um enriquecimento ambiental e alimentar para manterem os comportamentos similares aos apresentados em meio natural. Este estudo foi realizado com seis indivíduos de <em>Rhea americana</em> no bioma Cerrado, em Goiás. O objetivo deste trabalho foi avaliar a diversidade de comportamentos de emas, através de uma comparação entre os comportamentos de cativeiro e vida livre. Os animais tinham entre 4 e 10 meses durante o monitoramento, sendo que os mesmos indivíduos foram observados em cativeiro e vida livre. Observações comportamentais foram feitas com seis indivíduos durante um total de 120 h, sendo 60 h em cativeiro e 60 h em vida livre. Para a construção do etograma foram utilizados os métodos de observação <em>ad libitum</em> e animal focal. Identificamos um total de 19 comportamentos agrupados em oito categorias comportamentais: alimentação, encontro agonístico, locomoção, limpeza, vocalização, brincadeiras, inatividade e defesa. As diversidades de comportamentos tiveram frequências semelhantes nas fases de cativeiro e vida livre. Os comportamentos de locomoção e vocalização tiveram maior expressão em cativeiro, enquanto os comportamentos de limpeza, alimentação, encontro agonístico e brincadeira tiveram maior expressão em vida livre. Entretanto, não houve nenhuma diferença significativa entre os comportamentos de vida livre e cativeiro. Nesse estudo foram feitas observações apenas de machos, e por isso, sugerimos estudos adicionais que incluam machos e fêmeas, para serem observados possíveis comportamentos de reprodução. As reintroduções com emas, geralmente, não são bem sucedidas, considerando a alta taxa de mortalidade por um predador natural. Medidas adequadas de manejo poderiam evitar estes problemas. Desta forma, ações conservacionistas que visem a reintrodução de emas e que identifiquem os comportamentos de indivíduos em cativeiro e vida livre podem ajudar a melhorar o bem-estar animal em cativeiro e, desta forma, aumentar as chances de sobrevivência no ambiente natural. O enriquecimento ambiental e alimentar pode ser essencial para estimular os comportamentos naturais, evitando comportamentos estereotipados em cativeiro. Além disso, os métodos usados nesse estudo poderiam ser utilizados para outras aves ratitas.</p><p><strong>Palavras chave</strong>: Aves ratitas, bem-estar animal, Cerrado, observações comportamentais, <em>Rhea americana</em>.</p>
Insular environments are among the most endangered ecosystems as they face a myriad of anthropogenic stressors. Forest mammals perform a wide range of ecological services, with their persistence being vital for ecosystem functionality in both natural and artificial islands. Studies revealed that shrinkage in island size usually leads to the decay of mammal species richness and abundance in patchy landscapes.However, mammal species-area (SARs) and abundance-area (AARs) relationships can differ among insular environments: oceanic, fluvial, artificial, and land-bridge islands (i.e., natural islands connected to the mainland). Large dams create vast insularized landscapes after river impoundment, leading to pervasive habitat loss and potentially causing even worse biodiversity losses than other insular systems. We conducted an extensive literature search and used meta-analysis techniques to quantify the magnitude of SAR and AAR for forest mammals across different archipelago landscapes worldwide. After a screening process, we ended up with 26 studies comprising 55 different effect sizes representing the magnitude of SARs and AARs. Our global analysis unveiled a positive relationship between effect sizes and island area, with mammal species richness and abundance increasing in fluvial, oceanic, and artificial islands accordingly with island area, but not in land-bridge islands. These results demonstrate that, except for land-bridge islands, SAR and AAR are still fair models to predict mammal diversity. These results could improve the prediction of SAR and AAR in insular environments under habitat loss scenarios and propose sound conservation strategies since the rate at which insular communities have been lost is presently unknown. K E Y W O R D Sabundance-area-relationship, Forest mammals, global analysis, insular communities, metaanalysis, species-area relationship | INTRODUC TI ONThe species-area relationship (SAR) comprises one of ecology's few general laws for predicting species richness (Dodds, 2009;Lomolino, 1982;Rosenzweig, 1996;Warren et al., 2015). SAR postulates that the number of species is predicted mainly by area size. This prediction is at the core of the influential Theory of Island Biogeography, which postulates that larger and less isolated islands retain more species due to lower extinction and higher colonization events (MacArthur & Wilson, 1967). However, the SAR prediction
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