16 research outputs found

    Drivers of jaguar (Panthera onca) and puma (Puma concolor) predation on endangered primates within a transformed landscape in southern Mexico

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    Human pressures have increasingly placed keystone species, such as large cats, under threat. Together with forest loss, prey depletion is one of the main threats to the survival of jaguars (Panthera onca) and pumas (Puma concolor) throughout the Neotropics. Generally, primates are not considered main prey for jaguar and puma, and their inclusion in the diet could be indicative of ongoing prey species decline. Here, we investigate the effect of habitat type and disturbance on primate predation by large cats. Surveys took place during the dry seasons (March to June) of 2010 and 2011, covering a total of 608.5 km across 24 localities in the Uxpanapa Valley, Mexico. We found 65 felid scat samples with the aid of a wildlife scat detection dog, and then examined them to identify predator species and classify the prey remains they contained. Primates represented the most frequent prey (35%) for both jaguar and puma in our study site and constituted approximately half of the biomass consumed by these felines in the area. Primate remains were more likely to be found in scats surrounded by the lowest percentage of conserved forest or in areas surrounded by more villages, showing the potential effects of human activities on these species' populations. The high proportion of primates found in scats within our study site could be an early indication that populations of ungulates and other “typical” prey are beginning to collapse, and urgent conservation interventions are needed for both large cats and primates before they become locally extinct

    Variability in the summer movements, habitat use and thermal biology of two fish species in a temperate river

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    The ability of fish to cope with warm water temperatures in summer depends on factors including their thermal traits and the ability of individuals to access cool-water refugia. Knowledge is highly limited on the in situ responses of many fishes to elevated summer temperatures, including whether they express behavioural thermoregulation. The responses of two riverine species to summer water temperatures were tested here using the movement metrics, spatial habitat use and body temperatures of individual European barbel Barbus barbus (‘barbel’) and common bream Abramis brama (‘bream’) versus river temperatures. Acoustic biotelemetry was applied in the lower River Severn basin, western Britain, in summer 2021 (barbel) and 2022 (bream), where individuals could move across > 150 km of river, including a tributary of cooler water. Across all individuals, bream occupied 37 km of river length (mainstem only), with low inter-individual variability in their spatial habitat use, movements and body temperatures. In contrast, barbel occupied 62 km of river (main river/tributary), with relatively high inter-individual variability in spatial habitat use, movements and body temperatures, with higher variation in body temperatures as river temperatures increased (maximum mean daily temperature difference between individuals on the same day: 4.2 °C). Although warmer individuals generally moved more, their activity was greatest at relatively low temperatures and higher flows, and neither species revealed any evidence of behavioural thermoregulation during elevated temperatures. Enabling phenotypically diverse fish populations to express their natural behaviours and thermal preferences in summer water temperatures thus requires maintaining their free-ranging in thermally heterogenous habitats

    Living on the edge: forest edge effects on microclimate and terrestrial mammal activity in disturbed lowland forest in Sumatra, Indonesia

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    Species–environment relationships are often studied at large spatial scales, but effective conservation requires an understanding of local-scale environmental drivers and pressures. Widespread degradation and fragmentation of forests have increased the proportion of tropical mammal habitat that is affected by edge effects. Edge effects include greater exposure to anthropogenic disturbance and abiotic changes that synergistically influence how well populations can cope with climate change. We investigated relationships between distance to the forest edge, forest structure, microclimate and terrestrial mammal detections in a selectively logged forest at the boundary of Gunung Leuser National Park in Sumatra, Indonesia. We collected mammal detection data from motion-activated camera traps, microclimate data from automated climate data loggers and forest structure data from vegetation plots. Daily mean and maximum temperatures significantly decreased with distance from the forest edge, whereas tree height and minimum temperature increased. Mammal diversity was lower at the forest edge compared to the interior. Mammals were detected less frequently at the forest edge, although this relationship varied between mammal orders. Mammal detections were best explained by temperature, tree height and tree diameter at breast height. These results demonstrate that abiotic changes in forests brought on by edge effects have negative impacts on mammals, but these effects vary between mammal taxa because of differing sensitivities to human disturbance. Our findings highlight the importance of considering local-scale environmental drivers in determining species–environment relationships to identify key habitat features such as microclimate refuges that should be prioritized in ecosystem management

    The performance of Protected Areas for biodiversity under climate change

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    Global environmental changes have been driving large-scale shifts in the distributions of species and in the composition of biological communities. This has thrown the continuing value of Protected Areas (PAs) into question, given that PAs remain static, whereas species move, and they are predicted to continue to move under future climate scenarios. We consider empirical evidence on the observed performance of PAs during the last 40 years of anthropogenic climate change. Despite some losses of populations and species, PAs have continued to accommodate many species, which have shifted to higher elevations, to polewards-facing aspects, and into cooler microhabitats within PAs as the climate has warmed. Even when species have declined in some PAs, they often remain more abundant inside than outside PAs. Furthermore, losses from some PAs are offset by increases in others. As species expand their ranges polewards across fragmented landscapes in response to climate warming, the majority are disproportionately colonizing PAs as they go. Hence, PA networks are acting as stepping-stones of suitable breeding conditions and facilitating range shifts, with many species remaining protected across PA networks as a whole. Finally, there is some evidence that appropriate management of PAs may be able to slow climate-related declines and accelerate expansions. The 40-year track record of species responding to environmental change in PAs suggests that networks of PAs have been essential to biodiversity conservation and are likely to continue to fulfil this role in the future. The challenge for managers will be to consider the balance between retaining current species and encouraging colonization by new species

    Strikingly high effects of geographic location on fauna and flora of European agricultural grasslands

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    International audienceWild bees, spiders, earthworms and plants contribute considerably to biodiversity in grasslands and fulfil vital ecological functions. They also provide valuable services to agriculture, such as pollination, pest control and maintenance of soil quality. We investigated the responses of wild bees, spiders, earthworms and plants to geographic location, agricultural management and surrounding landscape variables using a dataset of grassland fields within 88 farms in six European regions. Regions and taxonomic groups were selected to have contrasting properties, in order to capture the multiple facets of European grasslands. Geographic location alone had a dominant effect on the fauna and flora communities. Depending on the taxonomic group, various agricultural management and surrounding landscape variables alone had an additional significant effect on observed species richness, rarefied species richness and/or abundance, but it was always small. Bee species richness and abundance decreased with increasing number of mechanical operations (e.g. cutting). Observed spider species richness and abundance were unrelated to measured aspects of agricultural management or to surrounding landscape variables, whereas rarefied species richness showed significant relations to nitrogen input, habitat diversity and amount of grassland habitats in the surroundings. Earthworm abundance increased with increasing nitrogen input but earthworm species richness did not. Observed plant species richness decreased with increasing nitrogen input and increased when there were woody habitats in the surroundings. Rarefied plant species richness decreased with mechanical operations. Investigating multiple regions, taxonomic groups and aspects of fauna and flora communities allowed identifying the main factors structuring communities, which is necessary for designing appropriate conservation measures and ensuring continued supply of services

    Conducting robust ecological analyses with climate data

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    Although the number of studies discerning the impact of climate change on ecological systems continues to increase, there has been relatively little sharing of the lessons learnt when accumulating this evidence. At a recent workshop entitled ‘Using climate data in ecological research’ held at the UK Met Office, ecologists and climate scientists came together to discuss the robust analysis of climate data in ecology. The discussions identified three common pitfalls encountered by ecologists: 1) selection of inappropriate spatial resolutions for analysis; 2) improper use of publically available data or code; and 3) insufficient representation of the uncertainties behind the adopted approach. Here, we discuss how these pitfalls can be avoided, before suggesting ways that both ecology and climate science can move forward. Our main recommendation is that ecologists and climate scientists collaborate more closely, on grant proposals and scientific publications, and informally through online media and workshops. More sharing of data and code (e.g. via online repositories), lessons and guidance would help to reconcile differing approaches to the robust handling of data. We call on ecologists to think critically about which aspects of the climate are relevant to their study system, and to acknowledge and actively explore uncertainty in all types of climate data. And we call on climate scientists to make simple estimates of uncertainty available to the wider research community. Through steps such as these, we will improve our ability to robustly attribute observed ecological changes to climate or other factors, while providing the sort of influential, comprehensive analyses that efforts to mitigate and adapt to climate change so urgently require

    A reply to ‘A meta-database of Holocene sediment cores for England: missing data’ (Tooley 2015)

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    We welcome the response of Tooley (2015) to our article describing a new meta-database of Holocene sediment cores for England. In our article we describe the online publication of this meta-database, arising from systematic meta-search. We define its scope and the meta-data it contains, before providing the data themselves (in the Electronic Supplementary Material online). We note that Prof. Tooley describes the idea of such a database as important and valuable, and we welcome the constructive approach he adopts throughout his article

    New perspectives on the ecology of early domestic fowl: an interdisciplinary approach.

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    Introduced into Europe during the Bronze- and Iron Ages as an exotic, non-native species, very little is currently understood about the origins and spread of early domestic fowl, Gallus gallus domesticus. Ecological niche modelling of extant Red Junglefowl, Gallus gallus, presents a unique opportunity to examine historical ecological implications associated with its descendant, the chicken, in early stages of domestication. We model the environmental conditions associated with Red Junglefowl populations both in south-east Asia, where the bird originates, and populations transported further afield as a consequence of human interaction. This allows us to establish the full extent of the ecological tolerance of the ancestor bird. We show that potential for suitable sets of environmental conditions for Red Junglefowl in Europe ranges from poor to limited, based on both current climate and when projecting to mid-Holocene (ca. 4000BC) climate simulations. This suggests that human intervention played a vital contribution during early domestication to ensure the future widespread success of the chicken. These conclusions offer new insights into the archaeological evidence. We identify areas in the native range as the probable location of first domestication, and not China as has been suggested. We suggest that a dispersal route into Europe via the Mediterranean offers the best ecological potential to aid survival for a recently domesticated version of this species. Identifying the environmental tolerances of Red Junglefowl may also aid future conservation of this species, now highly endangered in its true wild form

    Farmland biodiversity and agricultural management on 237 farms in 13 European and two African regions

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    Farmland is a major land cover type in Europe and Africa and provides habitat for numerous species. The severe decline in farmland biodiversity of the last decades has been attributed to changes in farming practices, and organic and low-input farming are assumed to mitigate detrimental effects of agricultural intensification on biodiversity. Since the farm enterprise is the primary unit of agricultural decision making, management-related effects at the field scale need to be assessed at the farm level. Therefore, in this study, data were collected on habitat characteristics, vascular plant, earthworm, spider, and bee communities and on the corresponding agricultural management in 237 farms in 13 European and two African regions. In 15 environmental and agricultural homogeneous regions, 6–20 farms with the same farm type (e.g., arable crops, grassland, or specific permanent crops) were selected. If available, an equal number of organic and non-organic farms were randomly selected. Alternatively, farms were sampled along a gradient of management intensity. For all selected farms, the entire farmed area was mapped, which resulted in total in the mapping of 11 338 units attributed to 194 standardized habitat types, provided together with additional descriptors. On each farm, one site per available habitat type was randomly selected for species diversity investigations. Species were sampled on 2115 sites and identified to the species level by expert taxonomists. Species lists and abundance estimates are provided for each site and sampling date (one date for plants and earthworms, three dates for spiders and bees). In addition, farmers provided information about their management practices in face-to-face interviews following a standardized questionnaire. Farm management indicators for each farm are available (e.g., nitrogen input, pesticide applications, or energy input). Analyses revealed a positive effect of unproductive areas and a negative effect of intensive management on biodiversity. Communities of the four taxonomic groups strongly differed in their response to habitat characteristics, agricultural management, and regional circumstances. The data has potential for further insights into interactions of farmland biodiversity and agricultural management at site, farm, and regional scale

    Data from: Improving estimates of environmental change using multilevel regression models of Ellenberg indicator values

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    Ellenberg indicator values (EIVs) are a widely used metric in plant ecology comprising a semi-quantitative description of species‘ ecological requirements. Typically, point estimates of mean EIV scores are compared to infer differences in the environmental conditions structuring plant communities – particularly in resurvey studies with no historical environmental data available. However, the use of point estimates as a basis for inference does not take into account variance among species EIVs within sampled plots, and gives equal weighting to means calculated from sites with differing numbers of species. We present a set of multilevel models – fitted with and without group-level predictors – to improve precision and accuracy of site mean EIV scores, and to provide more reliable inference on changing environmental conditions over spatial and temporal gradients in re-visitation studies. We compare multilevel model performance to GLMM’s fitted to point estimates of site mean EIVs. We also test the reliability of this method to improve inferences with incomplete species lists in some or all sample sites. Hierarchical modelling led to more accurate and precise estimates of site-level differences in mean EIV scores between time-periods, particularly for datasets with incomplete records of species occurrence. They also revealed directional environmental change within ecological habitat types, which estimates from GLMM’s were inadequate to detect. Multilevel models also highlighted a prominent role of hydrological differences as a driver of community change in our case study, which traditional use of EIVs failed to reveal. We have demonstrated that multilevel modelling of EIVs allows for a nuanced estimation of environmental change underlying ecological communities from plant assemblage data, leading to a better understanding of temporal dynamics of ecosystems. Further, the ability of these methods to perform well with missing data should increase the total set of historical data which can be used to this end
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