RESUMO
South Africa's decentralized approach to conservation entails that wildlife outside formally protected areas inhabit complex multi-use landscapes, where private wildlife business (ecotourism and/or hunting) co-exist in a human-dominated landscape matrix. Under decentralized conservation, wildlife is perceived to benefit from increased amount of available habitat, however it is crucial to understand how distinct management priorities and associated landscape modifications impact noncharismatic taxa, such as small mammals. We conducted extensive ink-tracking-tunnel surveys to estimate heterogeneity in rodent distribution and investigate the effect of different environmental factors on abundance patterns of two size-based rodent groups (small- and medium-sized species), across three adjacent management contexts in NE KwaZulu-Natal, South Africa: a private ecotourism game reserve, mixed farms and traditional communal areas (consisting of small clusters of houses interspersed with grazing areas and seminatural vegetation). Our hypotheses were formulated regarding the (1) area typology, (2) vegetation structure, (3) ungulate pressure and (4) human disturbance. Using a boosted-regression-tree approach, we found considerable differences between rodent groups' abundance and distribution, and the underlying environmental factors. The mean relative abundance of medium-sized species did not differ across the three management contexts, but small species mean relative abundance was higher in the game reserves, confirming an influence of the area typology on their abundance. Variation in rodent relative abundance was negatively correlated with human disturbance and ungulate presence. Rodent abundance seems to be influenced by environmental gradients that are directly linked to varying management priorities across land uses, meaning that these communities might not benefit uniformly by the increased amount of habitat promoted by the commercial wildlife industry.
RESUMO
The Egyptian mongoose is a carnivore mammal species that in the last decades experienced a tremendous expansion in Iberia, particularly in Portugal, mainly due to its remarkable ecological plasticity in response to land-use changes. However, this species may have a disruptive role on native communities in areas where it has recently arrived due to predation and the potential introduction of novel pathogens. We report reference information on the cultivable gut microbial landscape of widely distributed Egyptian mongoose populations (Herpestes ichneumon, n = 53) and related antimicrobial tolerance across environmental gradients. The panel of isolated species is consistent with the typical protein-based diet of a carnivore: Firmicutes predominate (89% of individuals), while Clostridiales, Enterobacteriales, and Lactobacillales are the major classes. Forty-one individuals (77.4%) harbour Clostridium spp. A spatial influence on mongooses' microbiota is confirmed by nonmetric multidimensional scaling analysis, with a significant contribution of municipality to their microbiota composition. Antimicrobial susceptibility testing of mongoose commensal bacteria to 28 compounds evidences xenobiotic tolerance of Escherichia coli (E. coli), enterococci, Salmonella Spartel and Mbandaka serotypes and Pseudomonas bacteria, among others. The common isolation of antimicrobial tolerant microbiota from the mongoose's gut suggests this species is exposed to anthropogenic influence and is affected by forestry and agricultural-related practices, reflecting its easy adaptation to ecological gradients across agroecosystems. We thus propose regular microbial and phenotypic resistance profiling of widely distributed mongooses as a sentinel tool for xenobiotics' lifecycle and ecosystem health in Portugal.
Assuntos
Microbioma Gastrointestinal , Herpestidae/microbiologia , Animais , Resistência a Medicamentos , Ecossistema , Espécies Introduzidas , Testes de Sensibilidade Microbiana , PortugalRESUMO
Human-Induced Rapid Environmental Change (HIREC), particularly climate change and habitat conversion, affects species distributions worldwide. Here, we aimed to (i) assess the factors that determine range patterns of European badger (Meles meles) at the southwestern edge of their distribution and (ii) forecast the possible impacts of future climate and landcover changes on those patterns. We surveyed 272 cells of 5 × 5 km, to assess badger presence and confirmed its occurrence in 95 cells (35%). Our models estimate that badger's presence is promoted by the occurrence of herbaceous fields and shrublands (5%-10%), and low proportions of Eucalyptus plantations (<~15%). Regions with >50% of podzols and eruptive rocks, higher sheep/goat density (>4 ind/km2), an absence of cattle, intermediate precipitation regimes (800-1000 mm/year) and mild mean temperatures (15-16 °C) are also more likely to host badgers. We predict a decrease in favourability of southern areas for hosting badgers under forecasted climate and landcover change scenarios, which may lead to a northwards retraction of the species southern distribution limit, but the overall landscape favourability is predicted to slightly increase. The forecasted retraction may affect community functional integrity, as its role in southern ecological networks will be vacant.
Assuntos
Mudança Climática , Ecologia , Monitoramento Ambiental , Mustelidae/fisiologia , Animais , Bovinos , Ecossistema , Eucalyptus/fisiologia , Humanos , Mustelidae/genética , Ovinos/fisiologiaRESUMO
The present study aims at assessing allometric relationships in the Sigmodontinae rodents (Calomys tener, Akodon cf. montensis, Necromys lasiurus, Oligoryzomys flavescens, and Oligoryzomys nigripes), and morphological variation among different habitats in human-dominated environments in Southeastern Brazil. We captured rodents using pitfall traps placed in Eucalyptus plantations, abandoned pastures, and remnants of secondary native vegetation, and took the following measurements: body mass, total length, body length, left hind foot length, and left ear length. Males were usually larger than females, except in N. lasiurus. There was no intraspecific difference in body condition among habitats, suggesting that Eucalyptus may not have a deleterious effect upon its residents. However, A. cf montensis from Eucalyptus plantations had longer feet than those from other vegetation associations, suggesting a possible adaptive response to the lower cover in the plantation environment, and its consequent higher predation risk, or alternatively that only individuals with greater dispersal ability are found in Eucalyptus plantations. Future studies should investigate a possible co-evolutionary predator-prey relationship, including rapid evolution by Sigmodontinae rodents in anthropogenic landscapes.
Assuntos
Ecossistema , Atividades Humanas , Sigmodontinae/anatomia & histologia , Sigmodontinae/fisiologia , Animais , Brasil , Feminino , MasculinoRESUMO
In the course of a study on the diet of two Portuguese carnivores, the red fox (Vulpes vulpes Linnaeus) and the common genet (Genetta genetta Linnaeus), 276 ticks were found inside the 940 scats analyzed. Prevalence in samples was 7.6% for both predators. Association of ticks with prey identified on scats, resulted in new data for Portugal on host-tick interactions [e.g. Ixodes acuminatus (Neumann, 1901) and wood mouse] and tick distribution pattern. These unusual findings, besides shedding some light on the host-tick Portuguese assemblage, revealed scats as a new source of biological information.