Loading...
32 results
Search Results
Now showing 1 - 10 of 32
- Protein metabolism and physical fitness are physiological determinants of body condition in Southern European carnivoresPublication . Santos, Nuno; Nakamura, Mónia; Rio-Maior, Helena; Álvares, Francisco; Barasona, Jose Ángel; Rosalino, L. M.; Santos, Maria Joao; Santos-Reis, Margarida; Ferreras, Pablo; Díaz-Ruiz, Francisco; Monterroso, Pedro SeabraThe physiological significance of biometric body condition indices (bBCI) is poorly understood. We hypothesized that bBCI are composite metrics of nutritional physiology, physical fitness and health. To test this hypothesis, we first compared the performance of eight bBCI, using 434 Southern European carnivores from six species as a model system; and then identified, by non-destructive methods, the hematology and serum biochemistry correlates of three selected bBCI. Fulton’s K Index, Major Axis Regression Residuals and Scaled Mass Index were the only bBCI insensitive to the effect of sex and age. The most informative physiological parameters in explaining the variation of these bBCI were the albumin (Effect Size (ES) = − 1.66 to − 1.76), urea (ES = 1.61 to 1.85) and total bilirubin (ES = − 1.62 to − 1.79). Hemoglobin and globulins (positive) and cholesterol (negative) were moderately informative (0.9 <|ES|< 1.5). This study shows that most bBCI do not control for the effect of age and sex in Southern European carnivores. Our results support that bBCI are composite measures of physiologic processes, reflecting a positive gradient from protein-poor to protein-rich diets, accompanied by increased physical fitness. Biometric body condition indices allow the integration of ecologically relevant physiological aspects in an easily obtained metric.
- Using green to cool the grey: Modelling the cooling effect of green spaces with a high spatial resolutionPublication . Grilo, Filipa; Pinho, Pedro; Aleixo, Cristiana; Catita, Cristina; Silva, Patrícia; Lopes, Nuno; Freitas, Catarina; Santos-Reis, Margarida; McPhearson, Timon; Branquinho, CristinaThe urban heat island effect creates warmer and drier conditions in urban areas than in their surrounding rural areas. This effect is predicted to be exacerbated in the future, under a climate change scenario. One way to mitigate this effect is to use the urban green infrastructure as a way to promote the cooling island effect. In this study we aimed to model, with a high spatial resolution, how Mediterranean urban parks can be maximized to be used as cooling islands, by answering the following questions: i) which factors influence the cooling effect and when?; ii) what type of green spaces contributes the most to the cooling effect?; iii) what is the cooling distance of influence? To answer these questions we established a sampling design where temperature and relative humidity were measured in different seasons, in locations with contrasting characteristics of green and grey cover. We were able to model the effect of green and grey spaces in the cooling island effect and build high spatial resolution predicting maps for temperature and relative humidity. Our study showed that even green spaces with reduced areas can regulate microclimate, alleviating temperature by 1-3 °C and increasing moisture by 2-8%, on average. Green spaces with a higher density of trees were more efficient in delivering the cooling effect. The morphology, aspect and level of exposure of grey surfaces to the solar radiation were also important features included in the models. Green spaces influenced temperature and relative humidity up to 60 m away from the parks' limits, whereas grey areas influenced in a much lesser range, from 5 m up to 10 m. These models can now be used by citizens and stakeholders for green spaces management and human well-being impact assessment.
- Three decades of research on Iberian wild Carnivora: trends, highlights, and future directionsPublication . Rosalino, Luís Miguel; Matias, Gonçalo; Carvalho, João; Álvares, Francisco; Azevedo, Alexandre; Bandeira, Victor; Fernandes, C; Ferreras, Pablo; Gortázar, Christian; Lozano, Jorge; Monterroso, Pedro; Palomares, Francisco; Santos, Nuno; Serra, Rodrigo; da Silva, André Pinto; Virgós, Emílio; Santos-Reis, MargaridaMammalian carnivores (Carnivora) are crucial components of landscapes, because of both their top-down effects on lower trophic level species and their sensitivity to bottom-up processes, such as limited food resources (e.g. due to climate instability). To understand their functional role in Iberian ecosystems more clearly, and to define effective plans for their management and conservation, it is crucial to sum up the available regional knowledge that can inform decision-making processes. We review bio-ecological research on wild Iberian carnivores over 30 years (1990–2020) and identify key knowledge gaps and priority avenues for future research. Based on a systematic review of the scientific literature, we aimed to: 1) summarise current knowledge; 2) assess species and ecoregion representativeness; 3) identify key research topics addressed and those lacking investment and 4) suggest key future research priorities. We examined 920 peer-reviewed articles involving wild Iberian mammalian carnivores, focusing on different bio-ecological issues. We found considerable heterogeneity in the topics and species investigated, as well as in the study areas (ecoregions) explored, with a mismatch between the research priorities identified by researchers and the knowledge gaps. We suggest that future research should prioritise: 1) rear-edge populations that are at the southwestern limits of the species' Eurasian range, thus being particularly sensitive to the increasing fragmentation and aridity of Iberian ecosystems, and that were less studied (e.g. brown bear Ursus arctos, stoat Mustela erminea, European mink Mustela lutreola and pine marten Martes martes); 2) less-studied topics, such as morphometry and body condition, ecophysiology, and reproductive biology, all of which provide essential information for species' management and conservation and 3) specific ecoregions for which studies on species' adaptations to environmental and anthropic contexts are lacking (e.g. northern ecoregions of Iberia, Iberian conifer forests and Northwest Iberian montane forests). Our review provides the necessary background to support future research on carnivore populations in Iberia.
- Influence of habitat edges on spatial and spatio-temporal occurrence patterns of mesocarnivores in landscapes dominated by Eucalyptus plantationsPublication . Pereira, Rita; Matias, Gonçalo; Santos-Reis, Margarida; Rosalino, L. M.Human population growth leads to drastic changes in landscape structure that often result in fragmentation. Fragmentation modifies the landscape and divides it into smaller habitat patches, creating habitat edges. These can affect the distribution and abundance of species and influence interspecific interactions. By comparing edges with habitat interiors, we intend to study how or if habitat edges influence mesocarnivores’: i) activity patterns, ii) co-occurrence in time, and iii) occupancy. We used camera-trapping to monitor the mesocarnivore community in two Eucalyptus plantations interspersed with patches of natural habitats, producing a landscape rich in habitat edges. 18 camera traps were placed in each study site, half on habitat edges and half in the interior habitat. We found a higher overlap of the mesocarnivores activity patterns in interior habitat than in habitat edges and a consistent positive effect for edge density on occupancy at both species and community-level. This study demonstrates that habitat edges shape mesocarnivores’ spatial and temporal behaviour. While spatially all species are positively affected by edges, as these can provide alternative or higher availability of resources, or act as travel corridors, to minimize interspecific interactions in edges, species activity overlap is greater within interior habitats than in edge habitats. Our findings support the design of better management measures in human-altered ecosystems, such as agricultural areas and forestry plantations, to guarantee the conservation of biodiversity while maintaining economic profitability.
- Urban trees through a functional traits’ lens: Exploring the interplay between tree functional groups and social-ecological factorsPublication . Grilo, Ana Filipa; McPhearson, Timon; Aleixo, Cristiana; Santos-Reis, Margarida; Branquinho, CristinaUrban trees’ functional traits influence their resilience to environmental changes and the delivery of ecosystem services. However, research on classifying urban trees into functional groups based on species traits - clusters of species with similar responses to environmental stressors and providing similar ecosystem services - and exploring the factors that shape their distribution is limited. This study classified a subset of urban trees in Lisbon, Portugal, into functional groups using 20 traits related to survival, establishment, tolerance, and ecosystem services delivery. We analyzed their distribution patterns across the city and modelled their abundance at the local scale, considering various social and ecological factors. These results were integrated with the municipality’s tree selection criteria. Our results revealed three functional groups - temperate, mediterranean, and tropical - each with the potential to deliver complementary ecosystem services. The distribution of the temperate functional group, the most abundant, was primarily associated with social factors, such as proximity to roads and public spaces. However, the temperate group had lower potential resilience to climate change due to its association with humid temperate climates, raising concerns in areas dominated by these species. In contrast, the mediterranean and tropical groups were influenced by both social and ecological factors, with trait data suggesting their potential to thrive under future climate conditions. These findings emphasize the need to enhance local functional diversity to increase ecological resilience and ensure a wider range of ecosystem services, especially in the context of climate adaptation. Overall, this analysis demonstrates the importance of social-ecological factors in shaping the functional composition of urban green spaces, offering insights into the roles of traits in sustainable species selection and urban tree management.
- Patterns and Drivers of Rodent Abundance across a South African Multi-Use LandscapePublication . C. Afonso, Beatriz; Swanepoel, Lourens H.; Rosa, Beatriz; Marques, Tiago A.; Rosalino, L. M.; Santos-Reis, Margarida; Curveira-Santos, GonçaloSouth 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.
- Context‐dependency in carnivore co‐occurrence across a multi‐use conservation landscapePublication . Curveira‐Santos, Gonçalo; Gigliotti, Laura; Sutherland, Chris; Rato, Daniela; Santos-Reis, Margarida; Swanepoel, Lourens H.Carnivore intraguild dynamics depend on a complex interplay of environmental affinities and interspecific interactions. Context-dependency is commonly expected with varying suites of interacting species and environmental conditions but seldom empirically described. In South Africa, decentralized approaches to conservation and the resulting multi-tenure conservation landscapes have markedly altered the environmental stage that shapes the structure of local carnivore assemblages. We explored assemblage-wide patterns of carnivore spatial (residual occupancy probability) and temporal (diel activity overlap) co-occurrence across three adjacent wildlife-oriented management contexts—a provincial protected area, a private ecotourism reserve, and commercial game ranches. We found that carnivores were generally distributed independently across space, but existing spatial dependencies were context-specific. Spatial overlap was most common in the protected area, where species occur at higher relative abundances, and in game ranches, where predator persecution presumably narrows the scope for spatial asymmetries. In the private reserve, spatial co-occurrence patterns were more heterogeneous but did not follow a dominance hierarchy associated with higher apex predator densities. Pair-specific variability suggests that subordinate carnivores may alternate between pre-emptive behavioral strategies and fine-scale co-occurrence with dominant competitors. Consistency in species-pairs diel activity asynchrony suggested that temporal overlap patterns in our study areas mostly depend on species' endogenous clock rather than the local context. Collectively, our research highlights the complexity and context-dependency of guild-level implications of current management and conservation paradigms; specifically, the unheeded potential for interventions to influence the local network of carnivore interactions with unknown population-level and cascading effects.
- Accounting for detection unveils the intricacy of wild boar and rabbit co-occurrence patterns in a Mediterranean landscapePublication . Barros, Ana Luísa; Curveira-Santos, Gonçalo; Marques, Tiago André; Santos-Reis, MargaridaThe patterns of species co-occurrence have long served as a primary approach to explore concepts of interspecific interaction. However, the interpretation of such patterns is difficult as they can result from several complex ecological processes, in a scale-dependent manner. Here, we aim to investigate the co-occurrence pattern between European rabbit and wild boar in an estate in Central Portugal, using two-species occupancy modelling. With this framework, we tested species interaction for occupancy and detection, but also the interdependencies between both parameters. According to our results, the wild boar and European rabbit occurred independently in the study area. However, model averaging of the detection parameters revealed a potential positive effect of wild boar's presence on rabbit's detection probability. Upon further analysis of the parameter interdependencies, our results suggested that failing to account for a positive effect on rabbit's detection could lead to potentially biased interpretations of the co-occurrence pattern. Our study, in spite of preliminary, highlights the need to understand these different pathways of species interaction to avoid erroneous inferences.
- Green spaces are not all the same for the provision of air purification and climate regulation services: The case of urban parksPublication . Vieira, Joana; Matos, Paula; Mexia, Teresa; Silva, Patrícia; Lopes, Nuno; Freitas, Catarina; Correia, Otília; Santos-Reis, Margarida; Branquinho, Cristina; Pinho, PedroThe growing human population concentrated in urban areas lead to the increase of road traffic and artificial areas, consequently enhancing air pollution and urban heat island effects, among others. These environmental changes affect citizen's health, causing a high number of premature deaths, with considerable social and economic costs. Nature-based solutions are essential to ameliorate those impacts in urban areas. While the mere presence of urban green spaces is pointed as an overarching solution, the relative importance of specific vegetation structure, composition and management to improve the ecosystem services of air purification and climate regulation are overlooked. This avoids the establishment of optimized planning and management procedures for urban green spaces with high spatial resolution and detail. Our aim was to understand the relative contribution of vegetation structure, composition and management for the provision of ecosystem services of air purification and climate regulation in urban green spaces, in particular the case of urban parks. This work was done in a large urban park with different types of vegetation surrounded by urban areas. As indicators of microclimatic effects and of air pollution levels we selected different metrics: lichen diversity and pollutants accumulation in lichens. Among lichen diversity, functional traits related to nutrient and water requirements were used as surrogates of the capacity of vegetation to filter air pollution and to regulate climate, and provide air purification and climate regulation ecosystem services, respectively. This was also obtained with very high spatial resolution which allows detailed spatial planning for optimization of ecosystem services. We found that vegetation type characterized by a more complex structure (trees, shrubs and herbaceous layers) and by the absence of management (pruning, irrigation and fertilization) had a higher capacity to provide the ecosystems services of air purification and climate regulation. By contrast, lawns, which have a less complex structure and are highly managed, were associated to a lower capacity to provide these services. Tree plantations showed an intermediate effect between the other two types of vegetation. Thus, vegetation structure, composition and management are important to optimize green spaces capacity to purify air and regulate climate. Taking this into account green spaces can be managed at high spatial resolutions to optimize these ecosystem services in urban areas and contribute to improve human well-being.
- Different increase rate in body mass of two marten species due to climate warming potentially reinforces interspecific competitionPublication . Wereszczuk, Anna; Hofmeester, Tim R.; Csanády, Alexander; Dumić, Tomislav; Elmeros, Morten; Lanszki, József; Madsen, Aksel B.; Müskens, Gerard; Papakosta, Malamati A.; Popiołek, Marcin; Santos-Reis, Margarida; Zuberogoitia, Iñigo; Zalewski, AndrzejMany species show spatial variation in body size, often associated with climatic patterns. Studying species with contrasting geographical patterns related to climate might help elucidate the role of different drivers. We analysed changes in the body mass of two sympatric medium-sized carnivores— pine marten (Martes martes) and stone marten (Martes foina)—across Europe over 59 years. The body mass of pine marten increased with decreasing latitude, whereas stone marten body mass varied in a more complex pattern across its geographic range. Over time, the average body mass of pine martens increased by 255 g (24%), while stone marten by 86 g (6%). The greatest increase of body mass along both martens’ geographic range was observed in central and southern Europe, where both species occur in sympatry. The body mass increase slowed down over time, especially in allopatric regions. The average pine/stone marten body mass ratio increased from 0.87 in 1960 to 0.99 in 2019, potentially strengthening the competition between them. Thus, a differential response in body size to several drivers over time might have led to an adaptive advantage for pine martens. This highlights the importance of considering different responses among interacting species when studying animal adaptation to climate change.