scholarly journals Variation in behavior drives multiscale responses to habitat conditions in timber rattlesnakes (Crotalus horridus)

2020 ◽  
Author(s):  
Andrew S. Hoffman ◽  
Annalee M. Tutterow ◽  
Meaghan R. Gade ◽  
Bryce T. Adams ◽  
William E. Peterman
Keyword(s):  
Habitat Selection ◽  
Environmental Variables ◽  
Forest Disturbance ◽  
Spatial Scales ◽  
Crotalus Horridus ◽  
Habitat Features ◽  
Timber Rattlesnakes ◽  
Site Use ◽  
Management Recommendations

AbstractVariations in both the behavior of wildlife and the scale at which the environment most influences the space use of wild animals (i.e., scale of effect) are critical, but often overlooked in habitat selection modeling. Ecologists have proposed that biological responses happening over longer time frames are influenced by environmental variables at larger spatial scales, but this has rarely been empirically tested. Here, we hypothesized that long-term patterns of behavior (i.e. lasting multiple weeks to months) would be associated with larger scales of effect than more sporadic behaviors. We predicted site use by 43 radio-telemetered timber rattlesnakes (Crotalus horridus) exhibiting four distinct, time-varying behaviors (foraging, digestion, ecdysis, and gestation) using remotely-sensed environmental variables related to forest structure and landscape topography. Among sites used by snakes, warmer temperatures and higher levels of forest disturbance were predictive of behaviors dependent on thermoregulation including gestation and ecdysis while more moderate temperatures and drier, more oak-dominated sites were predictive of foraging. Long-term behaviors were associated with larger spatial scales, supporting our hypothesis that the scale at which habitat selection occurs is linked to the temporal scale of relevant behaviors. Management recommendations based on single-scale models of habitat use that do not account for fine-scale variations in behavior may obscure the importance of potentially limiting habitat features needed for infrequent behaviors that are critically important for growth and reproduction of this and related species.

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 Optimization of spatial scale, but not functional shape, affects the performance of habitat suitability models: a case study of tigers (Panthera tigris) in Thailand

2021 ◽  
Vol 36 (2) ◽  
pp. 455-474
Author(s):  
Eric Ash ◽  
David W. Macdonald ◽  
Samuel A. Cushman ◽  
Adisorn Noochdumrong ◽  
Tim Redford ◽  
...  
Keyword(s):  
Habitat Selection ◽  
Habitat Suitability ◽  
Environmental Variables ◽  
Spatial Scales ◽  
Model Performance ◽  
Panthera Tigris ◽  
Habitat Suitability Models ◽  
Multi Scale ◽  
Single Scale ◽  
Optimized Model

Abstract Context Species habitat suitability models rarely incorporate multiple spatial scales or functional shapes of a species’ response to covariates. Optimizing models for these factors may produce more robust, reliable, and informative habitat suitability models, which can be beneficial for the conservation of rare and endangered species, such as tigers (Panthera tigris). Objectives We provide the first formal assessment of the relative impacts of scale-optimization and shape-optimization on model performance and habitat suitability predictions. We explored how optimization influences conclusions regarding habitat selection and mapped probability of occurrence. Methods We collated environmental variables expected to affect tiger occurrence, calculating focal statistics and landscape metrics at spatial scales ranging from 250 m to 16 km. We then constructed a set of presence–absence generalized linear models including: (1) single-scale optimized models (SSO); (2) a multi-scale optimized model (MSO); (3) single-scale shape-optimized models (SSSO) and (4) a multi-scale- and shape-optimized model (MSSO). We compared performance and resulting prediction maps for top performing models. Results The SSO (16 km), SSSO (16 km), MSO, and MSSO models performed equally well (AUC > 0.9). However, these differed substantially in prediction and mapped habitat suitability, leading to different ecological understanding and potentially divergent conservation recommendations. Habitat selection was highly scale-dependent and the strongest relationships with environmental variables were at the broadest scales analysed. Modelling approach had a substantial influence in variable importance among top models. Conclusions Our results suggest that optimization of the scale of resource selection is crucial in modelling tiger habitat selection. However, in this analysis, shape-optimization did not improve model performance.

Not all ponds are created equal: long-term beaver (Castor canadensis) lodge occupancy in a heterogeneous landscape

2020 ◽  
Vol 98 (3) ◽  
pp. 210-218 ◽  
Author(s):  
G.A. Hood
Keyword(s):  
Habitat Selection ◽  
Spatial Scales ◽  
Castor Canadensis ◽  
Site Occupancy ◽  
Occupancy Models ◽  
Spatial And Temporal Scales ◽  
Habitat Features ◽  
Non Linear ◽  
Original Habitat ◽  
Short Time

Modeling habitat selection often represents single spatial scales and short time periods. However, for species that dramatically modify environments upon initial colonization, non-linear interactions change original habitat to one where habitat selection is confounded by subsequent modifications by the organism itself. The ability of beavers (Castor canadensis Kuhl, 1820) to dramatically alter habitat components over time makes them a model species for examining habitat selection spatially and temporally. This study identified habitat features selected by a relatively long-lived, colonial species, and how selection influenced site occupancy over varying spatial scales. Remote sensing and field data provided spatial and temporal coverage of four measures of occupancy. Models of occupancy over an 11-year period, combined with environmental variables, identified features influencing occupancy, abandonment, and recolonization at 30, 50, and 100 m scales. Unlike many studies, % deciduous was a poor predictor of occupancy. Instead, pond area, % grassland, distance to a pond that was active at least once, and standard deviation (SD) of slope were important variables. SD of slope was the only variable not influenced by beavers. Examining species–habitat relationships over broader spatial and temporal scales, particularly for ecosystem engineers, enhances understanding of non-linear effects and how they influence perceptions of habitat selection.

scholarly journals Multi-scale habitat selection by mountain caribou in West Central Alberta

Rangifer ◽  
2003 ◽  
Vol 23 (5) ◽  
pp. 293 ◽  
Author(s):  
Tara Szkorupa ◽  
Fiona Schmiegelow
Keyword(s):  
Habitat Selection ◽  
Spatial Scales ◽  
Temporal Scales ◽  
Spatial And Temporal Scales ◽  
Multi Scale ◽  
Multiple Spatial Scales ◽  
West Central ◽  
Snow Conditions ◽  
Management Recommendations

This research suggests that mountain caribou select a suite of winter habitats, at multiple spatial scales, and under a range of snow conditions. Our findings lead to several management recommendations. In general, habitat selection by caribou necessitates management over large spatial and temporal scales.

scholarly journals Responses of Vertebrate Wildlife to Oil and Natural Gas Development: Patterns and Frontiers

2021 ◽  
Author(s):  
A. D. Chalfoun
Keyword(s):  
Natural Gas ◽  
Anthropogenic Activities ◽  
Spatial Scales ◽  
Habitat Type ◽  
Population Level ◽  
Low Frequencies ◽  
Natural Gas Development ◽  
The Usa ◽  
Oil And Natural Gas

Abstract Purpose of Review Anthropogenic activities can lead to the loss, fragmentation, and alteration of wildlife habitats. I reviewed the recent literature (2014–2019) focused on the responses of avian, mammalian, and herpetofaunal species to oil and natural gas development, a widespread and still-expanding land use worldwide. My primary goals were to identify any generalities in species’ responses to development and summarize remaining gaps in knowledge. To do so, I evaluated the directionality of a wide variety of responses in relation to taxon, location, development type, development metric, habitat type, and spatiotemporal aspects. Recent Findings Studies (n = 70) were restricted to the USA and Canada, and taxonomically biased towards birds and mammals. Longer studies, but not those incorporating multiple spatial scales, were more likely to detect significant responses. Negative responses of all types were present in relatively low frequencies across all taxa, locations, development types, and development metrics but were context-dependent. The directionality of responses by the same species often varied across studies or development metrics. Summary The state of knowledge about wildlife responses to oil and natural gas development has developed considerably, though many biases and gaps remain. Studies outside of North America and that focus on herpetofauna are lacking. Tests of mechanistic hypotheses for effects, long-term studies, assessment of response thresholds, and experimental designs that isolate the effects of different stimuli associated with development, remain critical. Moreover, tests of the efficacy of habitat mitigation efforts have been rare. Finally, investigations of the demographic effects of development across the full annual cycle were absent for non-game species and are critical for the estimation of population-level effects.

Evaluation of the CERES-Rice Model for Precision Nitrogen Management for Rice in Northeast China

2017 ◽  
Vol 8 (2) ◽  
pp. 328-332
Author(s):  
J. Zhang ◽  
Y. Miao ◽  
W.D. Batchelor
Keyword(s):  
Northeast China ◽  
Weather Data ◽  
Cool Season ◽  
Use Efficiency ◽  
Optimum N Rate ◽  
Management Recommendations ◽  
N Management ◽  
N Rates ◽  
N Use

Over-application of nitrogen (N) in rice (Oryza sativaL.) production in China is common, leading to low N use efficiency (NUE) and high environmental risks. The objective of this work was to evaluate the ability of the CERES-Rice crop growth model to simulate N response in the cool climate of Northeast China, with the long term goal of using the model to develop optimum N management recommendations. Nitrogen experiments were conducted from 2011–2015 in Jiansanjiang, Heilongjiang Province in Northeast China. The CERES-Rice model was calibrated for 2014 and 2015 and evaluated for 2011 and 2013 experiments. Overall, the model gave good estimations of yield across N rates for the calibration years (R2=0.89) and evaluation years (R2=0.73). The calibrated model was then run using weather data from 2001–2015 for 20 different N rates to determine the N rate that maximized the long term marginal net return (MNR) for different N prices. The model results indicated that the optimum mean N rate was 120–130 kg N ha–1, but that the simulated optimum N rate varied each year, ranging from 100 to 200 kg N ha–1. Results of this study indicated that the CERES-Rice model was able to simulate cool season rice growth and provide estimates of optimum regional N rates that were consistent with field observations for the area.

Protected Areas: offering security to whom, when and where?

2016 ◽  
Vol 43 (2) ◽  
pp. 172-180 ◽  
Author(s):  
ALICE B. KELLY ◽  
A. CLARE GUPTA
Keyword(s):  
Protected Areas ◽  
Environmental Conditions ◽  
Protected Area ◽  
Spatial Scales ◽  
Local Population ◽  
Well Being ◽  
Economic Context ◽  
Term Management ◽  
Over Time

SUMMARYThis study considers the issue of security in the context of protected areas in Cameroon and Botswana. Though the literature on issues of security and well-being in relation to protected areas is extensive, there has been less discussion of how and in what ways these impacts and relationships can change over time, vary with space and differ across spatial scales. Looking at two very different historical trajectories, this study considers the heterogeneity of the security landscapes created by Waza and Chobe protected areas over time and space. This study finds that conservation measures that various subsets of the local population once considered to be ‘bad’ (e.g. violent, exclusionary protected area creation) may be construed as ‘good’ at different historical moments and geographical areas. Similarly, complacency or resignation to the presence of a park can be reversed by changing environmental conditions. Changes in the ways security (material and otherwise) has fluctuated within these two protected areas has implications for the long-term management and funding strategies of newly created and already existing protected areas today. This study suggests that parks must be adaptively managed not only for changing ecological conditions, but also for shifts in a protected area's social, political and economic context.

Sign in / Sign up

Export Citation Format

Share Document