scholarly journals Predicting defaunation: accurately mapping bushmeat hunting pressure over large areas

2020 ◽  
Vol 287 (1922) ◽  
pp. 20192677
Author(s):  
Mairin C. M. Deith ◽  
Jedediah F. Brodie
Keyword(s):  
Real World ◽  
Landscape Heterogeneity ◽  
Strongly Correlated ◽  
Fine Scale ◽  
Habitat Features ◽  
Wild Meat ◽  
Large Animals ◽  
Human Foraging ◽  
Foraging Movements ◽  
Malaysian Borneo

Unsustainable hunting is emptying forests of large animals around the world, but current understanding of how human foraging spreads across landscapes has been stymied by data deficiencies and cryptic hunter behaviour. Unlike other global threats to biodiversity like deforestation, climate change and overfishing, maps of wild meat hunters' movements—often based on forest accessibility—typically cover small scales and are rarely validated with real-world observations. Using camera trapping data from rainforests across Malaysian Borneo, we show that while hunter movements are strongly correlated with the accessibility of different parts of the landscape, accessibility measures are most informative when they integrate fine-scale habitat features like topography and land cover. Measures of accessibility naive to fine-scale habitat complexity, like distance to the nearest road or settlement, generate poor approximations of hunters’ movements. In comparison, accessibility as measured by high-resolution movement models based on circuit theory provides vastly better reflections of real-world foraging movements. Our results highlight that simple models incorporating fine-scale landscape heterogeneity can be powerful tools for understanding and predicting widespread threats to biodiversity.

scholarly journals Ecological Connectivity in Agricultural Green Infrastructure:  Suggested Criteria for Fine Scale Assessment and Planning

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 807
Author(s):  
Simone Valeri ◽  
Laura Zavattero ◽  
Giulia Capotorti
Keyword(s):  
Land Cover ◽  
Green Infrastructure ◽  
Rural Areas ◽  
Urban Areas ◽  
Landscape Heterogeneity ◽  
Agricultural Landscapes ◽  
Spatial Pattern Analysis ◽  
Fine Scale ◽  
Unique Type

In promoting biodiversity conservation and ecosystem service capacity, landscape connectivity is considered a critical feature to counteract the negative effects of fragmentation. Under a Green Infrastructure (GI) perspective, this is especially true in rural and peri-urban areas where a high degree of connectivity may be associated with the enhancement of agriculture multifunctionality and sustainability. With respect to GI planning and connectivity assessment, the role of dispersal traits of tree species is gaining increasing attention. However, little evidence is available on how to select plant species to be primarily favored, as well as on the role of landscape heterogeneity and habitat quality in driving the dispersal success. The present work is aimed at suggesting a methodological approach for addressing these knowledge gaps, at fine scales and for peri-urban agricultural landscapes, by means of a case study in the Metropolitan City of Rome. The study area was stratified into Environmental Units, each supporting a unique type of Potential Natural Vegetation (PNV), and a multi-step procedure was designed for setting priorities aimed at enhancing connectivity. First, GI components were defined based on the selection of the target species to be supported, on a fine scale land cover mapping and on the assessment of land cover type naturalness. Second, the study area was characterized by a Morphological Spatial Pattern Analysis (MSPA) and connectivity was assessed by Number of Components (NC) and functional connectivity metrics. Third, conservation and restoration measures have been prioritized and statistically validated. Notwithstanding the recognized limits, the approach proved to be functional in the considered context and at the adopted level of detail. Therefore, it could give useful methodological hints for the requalification of transitional urban–rural areas and for the achievement of related sustainable development goals in metropolitan regions.

scholarly journals Predicting Microhabitat Suitability for an Endangered Small Mammal Using Sentinel-2 Data

2020 ◽  
Vol 12 (3) ◽  
pp. 562 ◽  
Author(s):  
Francesco Valerio ◽  
Eduardo Ferreira ◽  
Sérgio Godinho ◽  
Ricardo Pita ◽  
António Mira ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Landscape Heterogeneity ◽  
Remote Sensing Data ◽  
Predictive Distribution ◽  
Distribution Models ◽  
Explanatory Variables ◽  
Habitat Features ◽  
Main Challenge ◽  
Cabrera Vole ◽  
Sentinel 2

Accurate mapping is a main challenge for endangered small-sized terrestrial species. Freely available spatio-temporal data at high resolution from multispectral satellite offer excellent opportunities for improving predictive distribution models of such species based on fine-scale habitat features, thus making it easier to achieve comprehensive biodiversity conservation goals. However, there are still few examples showing the utility of remote-sensing-based products in mapping microhabitat suitability for small species of conservation concern. Here, we address this issue using Sentinel-2 sensor-derived habitat variables, used in combination with more commonly used explanatory variables (e.g., topography), to predict the distribution of the endangered Cabrera vole (Microtus cabrerae) in agrosilvopastorial systems. Based on vole surveys conducted in two different seasons over a ~176,000 ha landscape in Southern Portugal, we assessed the significance of each predictor in explaining Cabrera vole occurrence using the Boruta algorithm, a novel Random forest variant for dealing with high dimensionality of explanatory variables. Overall, results showed a strong contribution of Sentinel-2-derived variables for predicting microhabitat suitability of Cabrera voles. In particular, we found that photosynthetic activity (NDI45), specific spectral signal (SWIR1), and landscape heterogeneity (Rao’s Q) were good proxies of Cabrera voles’ microhabitat, mostly during temporally greener and wetter conditions. In addition to remote-sensing-based variables, the presence of road verges was also an important driver of voles’ distribution, highlighting their potential role as refuges and/or corridors. Overall, our study supports the use of remote-sensing data to predict microhabitat suitability for endangered small-sized species in marginal areas that potentially hold most of the biodiversity found in human-dominated landscapes. We believe our approach can be widely applied to other species, for which detailed habitat mapping over large spatial extents is difficult to obtain using traditional descriptors. This would certainly contribute to improving conservation planning, thereby contributing to global conservation efforts in landscapes that are managed for multiple purposes.

Pendulum Animal Impact Testing

2009 ◽  
Author(s):  
Stephen Forrest ◽  
John Paul Sodusta ◽  
Brian Herbst ◽  
Steven E. Meyer
Keyword(s):  
Real World ◽  
Impact Testing ◽  
Front Seat ◽  
Test Vehicle ◽  
Roof Structure ◽  
Pendulum Test ◽  
Large Animals ◽  
Serious Injuries ◽  
Roof Deformation

When vehicles collide with large animals, such as cattle, moose, elk or horses, the front seat occupants can be seriously or fatally injured; primarily due to roof deformation. In order to protect the front occupants in these accidents, it is necessary to understand the forces and energy involved in the interaction between the animal and the vehicle roof structure. The authors have developed a pendulum test incorporating an animal dummy to generate similar roof deformation to that experienced in real world animal impact accidents. The energy absorbed by the vehicle roof structure in the accident can then be determined by comparing the accident vehicle roof deformation to the pendulum test vehicle roof deformation. Ultimately, alternative roof structural designs are evaluated to demonstrate that a roof can perform well in this type of accident mode and reduce the risk for serious injuries to the occupants.

scholarly journals Fine-scale distributions of carnivores in a logging concession in Sarawak, Malaysian Borneo

2017 ◽  
Vol 86 ◽  
pp. 56-65 ◽  
Author(s):  
John Mathai ◽  
Rahel Sollmann ◽  
Michael E. Meredith ◽  
Jerrold L. Belant ◽  
Jürgen Niedballa ◽  
...  
Keyword(s):  
Fine Scale ◽  
Malaysian Borneo

Habitat selection by European badgers at multiple spatial scales in Portuguese Mediterranean ecosystems

2008 ◽  
Vol 35 (8) ◽  
pp. 835 ◽  
Author(s):  
Maria J. Santos ◽  
Paul Beier
Keyword(s):  
Habitat Selection ◽  
Spatial Scales ◽  
Local Population ◽  
Predictive Ability ◽  
Mediterranean Ecosystems ◽  
Strongly Correlated ◽  
Habitat Features ◽  
Agricultural Conversion ◽  
Animal Populations ◽  
European Badgers

Different habitat features can limit animal populations at different spatial scales. We examined habitat selection by Eurasian badger in a montado landscape in southern Portugal at four scales: core area (1 km2), home range (4 km2), social group territory (25 km2), and local population (100 km2). Our goals were to identify important habitats for conservation at each spatial scale (cell size) using candidate variables shown to be important by previous research. As expected, across all scales, badger occurrence was consistently and strongly correlated with dominance of cork oak and deciduous woodlands, and badgers seemed to avoid cultivated fields. Contrary to expectation, monocultures of conifers contributed positively to badger detection. The predictive ability of the models was poor at all scales, probably owing to our inability to include factors such as food, competitors, predators, undercover vegetation, and roads. Nonetheless, the models illustrate the importance to badgers of the montado, an ancient human-modified ecosystem that is threatened by current European Union agricultural conversion policies.

scholarly journals Fine scale patterns of genetic partitioning in the rediscovered African crocodile,Crocodylus suchus(Saint-Hilaire 1807)

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1901 ◽  
Author(s):  
Seth W. Cunningham ◽  
Matthew H. Shirley ◽  
Evon R. Hekkala
Keyword(s):  
Population Structure ◽  
Coastal Wetland ◽  
Drainage Basin ◽  
Landscape Heterogeneity ◽  
Landscape Connectivity ◽  
Central Africa ◽  
Fine Scale ◽  
Conservation Units ◽  
Widespread Species ◽  
Contemporary Gene Flow

Landscape heterogeneity, phylogenetic history, and stochasticity all influence patterns of geneflow and connectivity in wild vertebrates. Fine-scale patterns of genetic partitioning may be particularly important for the sustainable management of widespread species in trade, such as crocodiles. We examined genetic variation within the rediscovered African crocodile,Crocodylus suchus, across its distribution in West and Central Africa. We genotyped 109 individuals at nine microsatellite loci from 16 sampling localities and used three Bayesian clustering techniques and an analysis of contemporary gene flow to identify population structure across the landscape. We identified up to eight genetic clusters that largely correspond to populations isolated in coastal wetland systems and across large distances. Crocodile population clusters from the interior were readily distinguished from coastal areas, which were further subdivided by distance and drainage basin. Migration analyses indicated contemporary migration only between closely positioned coastal populations. These findings indicate high levels of population structure throughout the range ofC. suchusand we use our results to suggest a role for molecular tools in identifying crocodile conservation units for this species. Further research, including additional sampling throughout the Congo and Niger drainages, would clarify both the landscape connectivity and management of this species.

scholarly journals Oil palm expansion increases the vectorial capacity of dengue vectors in Malaysian Borneo

2021 ◽  
Author(s):  
Nichar Gregory ◽  
Robert M Ewers ◽  
Arthur Y.C. Chung ◽  
Lauren J Cator
Keyword(s):  
Land Use ◽  
Oil Palm ◽  
Disease Transmission ◽  
Vectorial Capacity ◽  
Adult Survival ◽  
Forest Conversion ◽  
Fine Scale ◽  
Temperature Dependent ◽  
Oil Palm Plantation ◽  
Malaysian Borneo

Changes in land-use and the associated shifts in environmental conditions can have large effects on the transmission and emergence of disease. Mosquito-borne disease are particularly sensitive to these changes because mosquito growth, reproduction, survival and susceptibility to infection are all thermally sensitive traits, and land use change dramatically alters local microclimate. Predicting disease transmission under environmental change is increasingly critical for targeting mosquito-borne disease control and for identifying hotspots of disease emergence. Mechanistic models offer a powerful tool for improving these predications.  However, these approaches are limited by the quality and scale of temperature data and the thermal response curves that underlie predictions. Here, we used fine-scale temperature monitoring and a combination of empirical, laboratory and temperature-dependent estimates to estimate the vectorial capacity of Aedes albopictus mosquitoes across a tropical forest – oil palm plantation conversion gradient in Malaysian Borneo. We found that fine-scale differences in temperature between logged forest and oil palm plantation sites were not sufficient to produce differences in temperature-dependent trait estimates using published thermal performance curves. However, when measured under field conditions a key parameter, adult abundance, differed significantly between land-use types, resulting in estimates of vectorial capacity that were 1.5 times higher in plantations than in forests. The prediction that oil palm plantations would support mosquito populations with higher vectorial capacity was robust to uncertainties in our adult survival estimates.  These results provide a mechanistic basis for understanding the effects of forest conversion on mosquito-borne disease risk, and a framework for interpreting emergent relationships between land-use and disease transmission. As rising demand for palm oil products drives continued expansion of plantations, these findings have important implications for conservation, land management and public health policy at the global scale.

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