Resource Utilization Functions Research Articles

Dynamic Plant–Herbivore Interactions between Bison Space Use and Vegetation Heterogeneity in a Tallgrass Prairie

Investigations into plant–herbivore interactions are of importance for understanding grassland ecosystem dynamics. Our research quantified the effects of vegetation heterogeneity at a patch scale of 30 m on bison space use in a tallgrass prairie through the analyses of the resource utilization function. In addition, we assessed the vegetation heterogeneity associated with bison locations by comparing the patch-scale vegetation characteristics between areas with high and low bison space use through Mann–Whitney U tests. Furthermore, we simulated the interactions between bison and vegetation patches (2 × 2 m) during the early growing season for the lowland topographic positions using agent-based modeling (ABM) as a preliminary study of linking bison foraging site selection with vegetation responses to bison grazing dynamically. The bison grazing strategy in the ABM of the grassland system was adjusted to ensure consistency in the vegetation pattern variations related to bison space use between the simulation and the empirical on-the-ground observations. The results indicated the following: (1) The effects of the patch-scale vegetation heterogeneity on the bison foraging site selection varied across the seasons, which were most evident in the middle of the growing season. (2) A relatively high level of bison space use generally resulted in diverse grassland canopies with high variability and interspersion. (3) From the ABM of the grassland system, it can be implied that bison select patches with high quality and quantity at the beginning of the growing season; as the vegetation quality and quantity improve overall, the bison graze randomly. This pattern was confirmed by observations of the bison foraging site selection in our study site. The ABM proved to be valuable in exploring and elucidating the underlying mechanisms of the grassland dynamics with a native North American grazer.

Trade-offs predicted by metabolic network structure give rise to evolutionary specialization and phenotypic diversification.

Mitigating trade-offs between different resource-utilization functions is key to an organism’s ecological and evolutionary success. These trade-offs often reflect metabolic constraints with a complex molecular underpinning; therefore, their consequences for evolutionary processes have remained elusive. Here, we investigate how metabolic architecture induces resource-utilization constraints and how these constraints, in turn, elicit evolutionary specialization and diversification. Guided by the metabolic network structure of the bacterium Lactococcus cremoris, we selected two carbon sources (fructose and galactose) with predicted coutilization constraints. By evolving L. cremoris on either fructose, galactose, or a mix of both sugars, we imposed selection favoring divergent metabolic specializations or coutilization of both resources, respectively. Phenotypic characterization revealed the evolution of either fructose or galactose specialists in the single-sugar treatments. In the mixed-sugar regime, we observed adaptive diversification: both specialists coexisted, and no generalist evolved. Divergence from the ancestral phenotype occurred at key pathway junctions in the central carbon metabolism. Fructose specialists evolved mutations in the fbp and pfk genes that appear to balance anabolic and catabolic carbon fluxes. Galactose specialists evolved increased expression of pgmA (the primary metabolic bottleneck of galactose metabolism) and silencing of ptnABCD (the main glucose transporter) and ldh (regulator/enzyme of downstream carbon metabolism). Overall, our study shows how metabolic network architecture and historical contingency serve to predict targets of selection and inform the functional interpretation of evolved mutations. The elucidation of the relationship between molecular constraints and phenotypic trade-offs contributes to an integrative understanding of evolutionary specialization and diversification.

Online Service Function Chain Deployment for Live-Streaming in Virtualized Content Delivery Networks: A Deep Reinforcement Learning Approach

Video delivery is exploiting 5G networks to enable higher server consolidation and deployment flexibility. Performance optimization is also a key target in such network systems. We present a multi-objective optimization framework for service function chain deployment in the particular context of Live-Streaming in virtualized content delivery networks using deep reinforcement learning. We use an Enhanced Exploration, Dense-reward mechanism over a Dueling Double Deep Q Network (E2-D4QN). Our model assumes to use network function virtualization at the container level. We carefully model processing times as a function of current resource utilization in data ingestion and streaming processes. We assess the performance of our algorithm under bounded network resource conditions to build a safe exploration strategy that enables the market entry of new bounded-budget vCDN players. Trace-driven simulations with real-world data reveal that our approach is the only one to adapt to the complexity of the particular context of Live-Video delivery concerning the state-of-art algorithms designed for general-case service function chain deployment. In particular, our simulation test revealed a substantial QoS/QoE performance improvement in terms of session acceptance ratio against the compared algorithms while keeping operational costs within proper bounds.

Space-use patterns of Malay civets (Viverra tangalunga) persisting within a landscape fragmented by oil palm plantations

ContextAgricultural land use is expanding and is a major driver of the biodiversity crisis. Land use planning initiatives seeking to optimize wildlife conservation are hindered by a lack of baseline data quantifying species’ tolerance to human-modified landscapes.ObjectivesWe explored the influence of landscape characteristics on the fine-scale space-use patterns of a model generalist carnivore, the Malay civet (Viverra tangalunga), within degraded tropical forests and oil palm plantations.MethodsWe collected over 20,000 GPS locations from 21 male civets in Sabah, Malaysian Borneo to evaluate the species’ space-use patterns and habitat utilization processes. We used movement-based modeling to determine home ranges, and combined the results with high-resolution remotely sensed habitat characteristics. We developed resource utilization functions to determine individual and population-level functional responses to proximity to plantation edge, distance to water, terrain ruggedness, forest structure, and functional diversity.ResultsCivets foraged within oil palm plantations, yet all animals utilized forests. Home ranges scaled with proportion of plantation within both total and core ranges. Resource utilization functions reported individualism in the species’ responses to habitat characteristics. At the population-scale, civets consistently and more intensely used habitats closer to plantation edges and taller tree canopies.ConclusionsAlthough plantations did not pose an inhospitable matrix, oil palm agriculture is a less suitable habitat than remnant forests for civets. Proximity measures and forest structure influenced the spatial behaviors of this adaptable generalist, highlighting the importance of protected areas. We recommend land-sparing and -sharing approaches to facilitate carnivore persistence across oil palm degraded landscapes.

Interference competition between wolves and coyotes during variable prey abundance.

Interference competition occurs when two species have similar resource requirements and one species is dominant and can suppress or exclude the subordinate species. Wolves (Canis lupus) and coyotes (C. latrans) are sympatric across much of their range in North America where white‐tailed deer (Odocoileus virginianus) can be an important prey species. We assessed the extent of niche overlap between wolves and coyotes using activity, diet, and space use as evidence for interference competition during three periods related to the availability of white‐tailed deer fawns in the Upper Great Lakes region of the USA. We assessed activity overlap (Δ) with data from accelerometers onboard global positioning system (GPS) collars worn by wolves (n = 11) and coyotes (n = 13). We analyzed wolf and coyote scat to estimate dietary breadth (B) and food niche overlap (α). We used resource utilization functions (RUFs) with canid GPS location data, white‐tailed deer RUFs, ruffed grouse (Bonasa umbellus) and snowshoe hare (Lepus americanus) densities, and landscape covariates to compare population‐level space use. Wolves and coyotes exhibited considerable overlap in activity (Δ = 0.86–0.92), diet (B = 3.1–4.9; α = 0.76–1.0), and space use of active and inactive RUFs across time periods. Coyotes relied less on deer as prey compared to wolves and consumed greater amounts of smaller prey items. Coyotes exhibited greater population‐level variation in space use compared to wolves. Additionally, while active and inactive, coyotes exhibited greater selection of some land covers as compared to wolves. Our findings lend support for interference competition between wolves and coyotes with significant overlap across resource attributes examined. The mechanisms through which wolves and coyotes coexist appear to be driven largely by how coyotes, a generalist species, exploit narrow differences in resource availability and display greater population‐level plasticity in resource use.

Plastics in the US: toward a material flow characterization of production, markets and end of life

Managing plastics has become a focal issue of the Anthropocene. Developments in plastic materials have made possible many of the technologies and conveniences that define our modern life. Yet, plastics are accumulating in landfills and natural environments, impacting resource utilization and ecosystem function. Solutions to these rising problems will require action and coordination across all stages of plastics value chains. Here, we offer the first contemporary plastics material flow by resin type through the US economy, encompassing 2017 production, sales, use markets and end-of-life management. This roadmap, while sourced from disparate and incomplete data, provides stakeholders with a system-scale context for understanding challenges, opportunities and implications of future interventions. More than three-quarters of the plastics reaching end of life went to landfill, and less than 8% was recycled. Packaging was the largest defined use market for plastics, but two thirds of the plastic put into use in 2017 went into other markets, including consumer products, electronics, buildings and transportation. In nearly all uses, increased coordination between material and product innovation and design and end-of-life recovery and recycling are needed. Alignment of technology, policy and market drivers will be necessary to reduce plastic waste and improve the circularity of plastic materials.

Distributed bandwidth selection approach for cooperative peer to peer multi-cloud platform

Network function virtualization (NFV) is a well-accepted software-defined network (SDN) architecture concept. NFV is severally used in cloud platform to enhance the utilization of available network resources. The concept behind NFV is a design of software process architecture with a bunch of collaborative resource utilization functions. The progression of platform providers builds a communication service plan with the help of virtual machines. We propose biogeography-based optimization (BBO) technique in order to enrich virtual network functions (VNFs) to utilize available bandwidth resource in an energy-efficient and cost-effective manner. The cooperative bandwidth sharing approach using BBO reduces delay mean at the time of supervision the impending requests in a multi-cloud environment. Experimental results validate that the utilization of available bandwidth has increased using the proposed scheme with respect to the single user-dedicated resource allocation and multi-user dedicated resource allocation. Delay means, as well as subscription cost, has reduced compared to the existing methods. The correctness of the investigational outcome has been established using an experimental setup along with the proposed algorithm.

Differential Resource Use between Native and Introduced Gray Squirrels

ABSTRACTDifferences in habitat requirements and the spatial distribution of habitat for native and introduced species can determine outcomes of biological invasions. Introduced eastern gray squirrels (Sciurus carolinensis) have displaced native red squirrels (S. vulgaris) in Europe and have been implicated as a contributing factor to the decline of western gray squirrels (S. griseus) in North America. Eastern and western gray squirrels are associated with oak (Quercus spp.), but little is known about how these species interact. From April 2007 to April 2012, we radio‐tracked sympatric eastern and western gray squirrels in western Washington to compare habitat use and evaluate competitive interactions. We developed resource utilization functions for each species and evaluated distribution of habitat on Joint Base Lewis‐McChord, Washington, USA. Both species shared affinity for closed canopy forests and oaks; however, important differences in relationships with riparian areas and shrub cover resulted in low overlap in habitat distribution, which likely limited potential competitive interactions. Eastern gray squirrels appeared restricted to areas around wetlands likely because they supported the deciduous tree species that comprise habitat for this species in its native range. Use by western gray squirrels, but not eastern gray squirrels, significantly decreased with increasing shrub cover. Forestry practices that promote mixed oak‐conifer with little shrub cover in uplands can benefit western gray squirrels and minimize interactions with eastern gray squirrels. © 2020 The Wildlife Society.

Summer Habitat Use of Female Mule Deer in Oregon

ABSTRACTMule deer (Odocoileus hemionus hemionus) populations have been declining throughout their range and loss or deterioration of habitat has been associated with observed trends. An understanding of the relative importance of landscape characteristics in affecting mule deer distribution will allow wildlife managers that alter habitat to make predictions regarding future use by mule deer, which is likely to influence mule deer population size and recruitment. We radio‐marked 376 adult female mule deer with global positioning system‐collars from 2006–2012 in south‐central Oregon, USA, to evaluate summer habitat use. We used multiple linear regression to develop a resource utilization function (RUF) model for mule deer to relate landscape characteristics to the height of a utilization distribution estimated with a Brownian bridge movement model. We validated the predictive capacity of the RUF model with locations from an independent dataset of 95 deer that summered within our study area. Our best model describing mule deer habitat use included 5 covariates: overstory canopy cover, slope, distance to forest edge, distance to intermittent or perennial streams, and distance to dirt roads. Predicted intensity of use peaked at roughly 40% canopy cover and decreased with increasing slope and distance from forest edge. Predicted use was greater closer to streams and decreased, albeit slightly, with increasing distance from dirt roads. Model validation revealed our model predicted summer habitat use by mule deer very well. Our results provide a basis for predicting effects of future land management actions on mule deer habitat use on summer range. Forest management prescriptions that maintain canopy cover around 40% and create forest edge may benefit mule deer in south‐central Oregon and other forested ecosystems, particularly if these prescriptions are implemented on areas with gentle slopes and access to streams. © 2019 The Wildlife Society.

Dormant Season Grazing: Effect of Supplementation Strategies on Heifer Resource Utilization and Vegetation Use

Grazing dormant forage under low-input heifer development strategies typically exposes cattle to low-quality forage. Protein supplementation while grazing dormant range can enhance heifer growth and reproductive performance. We examined resource utilization of heifers and the effects of dormant season grazing on residual vegetation characteristics under two supplementation management strategies. Approximately 100 weaned composite heifer calves were randomly selected and placed into one of two supplementation treatments in each of 2 yr, one receiving a free access 62% crude protein self-fed concentrate and the other receiving a daily hand-fed 20% crude protein cake. Grazing occurred from December (2015 and 2016) through March (2016 and 2017). Thirty transects were randomly located within each pasture for measuring vegetation quality and structure before and after grazing. Daily space use and behavior was evaluated for 21 individuals within each treatment using global positioning system (GPS) collars and resource utilization functions. Heifers supplemented with concentrated protein spent more time grazing per day than heifers supplemented with cake (6.92 ± 0.18, 6.24 ± 0.17 h). Relative use by heifers in the cake treatment was negatively related to horizontal distance from the supplement delivery site early to midwinter (β¯ˆ = −0.41 ± 0.16, −0.53 ± 0.17). Both treatments selected grazing locations relative to standing biomass of perennial grasses (β¯ˆ = 0.0005 ± 0.00004) and crude protein (β¯ˆ = 0.12 ± 0.007). However, resource selection was highly variable among individuals for both supplementation treatments. We found no treatment effects on pre-post grazing differences in residual cover of litter, grass, forbs and shrubs (P > 0.24). However, the time period when grazing occurred had an effect on residual vegetation conditions (P < 0.01). Our results indicate high levels of variability in grazing site selection by heifers, suggesting future research should incorporate individual animal measurements in an attempt to account for individual animal variability.

Northern Bobwhite (Colinus virginianus) Space Use Minimally Affected by Oil and Gas Development

Despite the fact that the northern bobwhite (Colinus virginianus Linnaeus; hereafter, bobwhite) is one of the most well-studied and widely distributed wildlife species in North America, we know little about how bobwhite respond to oil and gas infrastructure. We investigated the impacts of oil and gas development on space use of bobwhite using a multiseason approach. We captured and monitored bobwhite in the breeding season (1 April–30 September, n = 135 individuals) and nonbreeding season (1 October–31 March, n = 30 coveys) and modeled their habitat selection in a resource-utilization function (third order, within home range selection) and resource-selection function (second order, home range selection) format. Generally, energy infrastructure effects on bobwhite were neutral, but breeding season bobwhite did select for areas near low-traffic roads (β = −0.31 ± 0.15 SE). In the nonbreeding season, coveys selected for areas within their home range with a limited viewshed (i.e., areas with limited visibility of anthropogenic structures; β = −0.03 ± 0.02 SE). Selection differed between sexes for well pads (t = −2.12, P = 0.04) but was otherwise similar. At the level of home range selection, bobwhite exhibited a preference for areas with a low density of oil and gas wells and a high density of low-traffic roads during both the breeding and nonbreeding seasons (breeding: βwell = −0.14 ± 0.02, βroad = 0.26 ± 0.27; nonbreeding: βwell = −0.08 ± 0.03, βroad = 0.16 ± 0.03). As a generalist species, bobwhite appear to be largely tolerant of energy infrastructure and associated disturbances at moderate levels of development but may be sensitive to high densities of oil and gas pads.

COMPOSITE APPLICATION DISTRIBUTION METHODS MODELING

The subject of consideration are algorithms for optimal distribution of existing pool of computing resources between composite applications and algorithm of utilization of resources on computing blocks. The purpose of the article is to analyze the results of simulation and mathematical modeling of the resource allocation process between composite applications, depending on the distribution option. Results The efficiency of existing dynamic planning algorithms that are related to the greedy algorithm class is considered. They find a locally optimal solution at each step. The boundary of effective planning of algorithms based on clustering approach is revealed. The efficiency of using ant colony optimization algorithm and algorithms of cluster approach using ant colony optimization algorithm is shown. The simulation of the distribution of the composite application is carried out, depending on the complexity of the graph construction. The dependence of the execution time of the composite application on utilization of resources on the calculated blocks is obtained. Using the resource utilization function, the quality of the distribution of composite application resources is analyzed, depending on the amount of data transferred to the calculations. Conclusions. Data on the quality of resource allocation is obtained, depending on such parameters as the time of implementation of the composite application, the volume of transmitted data, the complexity of the graph construction. A method for choosing the optimal resource allocation algorithm between composite applications depending on the listed parameters is proposed. This will allow you to quickly dispose of distributed computing blocks that are occupied by calculating a distributed task, which will speed up the computation of distributed tasks on an existing pool of computing blocks.

Lesser prairie‐chicken space use in relation to anthropogenic structures

ABSTRACTThe Southern Great Plains has been altered by conversion of native grassland to row‐crop agriculture, which is considered the primary cause of declining lesser prairie‐chicken (Tympanuchus pallidicinctus) populations. However, recent analyses indicate that direct loss of grassland has slowed while lesser prairie‐chicken populations continue to decline, suggesting that remaining grasslands potentially suffer from degradation by various land uses (e.g., increased anthropogenic disturbance). Understanding the spatial ecology of lesser prairie‐chickens relative to anthropogenic structures is important for conservation planning, habitat management, and infrastructure mitigation. We investigated effects of proximity to anthropogenic structures on home range and nest placement (second‐order selection) and within home range space use (third‐order selection) of radio‐marked lesser prairie‐chickens (n = 285) at 2 scales of selection using resource utilization functions and resource selection functions. We collected data from birds marked in the Mixed‐Grass Prairie and Short‐Grass Prairie ecoregions of Kansas, USA, from 15 March 2013 to 14 March 2016. Home range placement did not vary by region or season, and lesser prairie‐chickens placed home ranges farther from powerlines and roads than would be expected at random. As distance increased from 0 to 3 km away from roads and powerlines, the relative probability of home range placement increased 1.66 and 1.54 times, respectively. Distance to powerline was the single most consistent variable negatively affecting nest placement. As the distance from powerline increased from 0 to 3 km, the relative probability of nest placement increased 2.19 times. Distance to oil well did not influence placement of home ranges or nests. When pooled across regions, lesser prairie‐chickens exhibited behavioral avoidance of powerlines, roads, and oil wells within their home range. Lesser prairie‐chickens, on average, used space at greater intensities within their home range farther from wells, powerlines, and roads than available. Across breeding season phases, we found no evidence of increased behavioral avoidance of anthropogenic structures during the nesting or brooding phases compared to the lekking or post‐breeding phases. Within home range space use during the brooding phase was not related to powerlines, wells, or roads. Our results indicate that avoidance of anthropogenic structures may result in functional habitat loss and continued fragmentation of remaining grassland habitat. Reduction or elimination of anthropogenic development in quality lesser prairie‐chicken habitat and concentrating new development in already altered areas that are avoided by lesser prairie‐chickens and no longer considered available habitat may reduce continued habitat degradation throughout the species’ range and aid in population persistence. © 2018 The Wildlife Society.

African Lion (Panthera leo) Space Use in the Greater Mapungubwe Transfrontier Conservation Area

Large carnivores are key drivers of ecosystem structure and function, yet their populations are declining worldwide. African lion (Panthera leo) populations have decreased significantly in recent decades with an estimated 23 000 lions left in Africa. Successful conservation efforts rely on a sound understanding of how animals utilize their surrounding habitat. We used movement data from GPS collars to investigate patterns and drivers of seasonal space use by free-roaming lions in the Greater Mapungubwe Transfrontier Conservation Area (GM-TFCA). We developed individual and population-level resource utilization functions (RUF) from 2008 to 2015. RUFs relate non-uniform space use within a home range to landscape metrics in a multiple regression framework. We identified six landscape features hypothesized a priori to be good predictors of lion space use: land use, land cover, elevation, terrain ruggedness, distance to human settlements and rivers. Only elevation during the dry season was a significant factor detected for lion space use ( ± S.E.) (-0.278 ± 0.107, CI = -0.4881, -0.0676). Across seasons, lions varied in their avoidance of human settlements, but 12 of 18 (67%) individuals selected areas within their home ranges that were farther from human settlements. Lions moved randomly across the landscape independent of vegetation type regardless of season. In season-specific analyses, some lions avoided human settlements (dry season: 45%, [n = 10] utilized areas farther from settlements; wet season: 50% [n = 9]). The lack of avoidance of settlements by some lions in our study also confirms that individual variation among lions can lead to human—wildlife conflicts. Perhaps the most critical observation from our study is that individual lions acted very differently as they used the landscape, which suggests the need for management plans to be landscape and case-specific.

On the Design of Efficient Residue-to-Binary Converters

Residue-to-binary (R/B) converter plays a pivotal role in various computer arithmetic circuits and cryptographic applications. In this paper, efficient hardware implementation of R/B converters have been reported for the moduli set of (2n-1,2n,2n+1) and (2n-1,2n,2n+1). The functionality of the theorems have been verified using VHSIC (Very High Speed Integrated Circuit) hardware description language (VHDL) and synthesized using Xilinx ISE in the device xc6vlx760ff1760-1. Performance parameters have been compared as a function of propagation delay (ns), power (nW) consumption and FPGA resource utilization. The simulations were carried out for three different values of n. Simulation results also offered the pros and cons of the above mentioned parameters.

Fine-scale spatial and seasonal rangeland use by cattle in a foot-and-mouth disease control zones

Overgrazing of ranglands and foot-and-mouth disease (FMD) are persistent problems in the communal lands bordering the Kruger National Park (KNP) and the adjacent private game reserves in South Africa. Improved livestock management is needed to address these problems, and detailed understanding of cattle ranging behaviour in the FMD control zones is central to improving livestock management. We used environmental data on seasonal variation in forage quality (nitrogen content) and quantity (biomass) derived from high resolution satellite imagery, coupled with cattle GPS locations, to develop a resource utilization function of cattle space use patterns and predicted spatial patterns of their probability of occurrence in the wet and dry seasons. We calculated cattle resource utilization distributions and delineated home ranges of cattle from six villages by applying utilization kernels using the plug-in method as a bandwidth estimator. The overlap between seasonal home ranges was 61% and between core areas 49%, indicating seasonal selectivity mainly within the home ranges. Cattle selected forage with higher quantity and quality during the dry season but behaved like bulk grazers in the wet season. Furthermore, we found that herds in the dry season usually have smaller home ranges and stay closer to water sources and villages than in the wet season. Our prediction maps highlight seasonal differences in probability of cattle occurrence, with implications for rangelands management strategies to minimalize overgrazing and FMD transmission.

Factors influencing the movements during the breeding season of a female booted eagle (Aquila pennata) tagged by satellite in central Catalonia (Spain)

Abstract Foraging movements during the breeding season are a poorly studied aspect of booted eagle behaviour. We have investigated the relationship between weather and other abiotic factors and foraging behaviour, and also resource use by a female booted eagle, tagged by satellite-GPS transmitter in central Catalonia, during summer 2012 and spring 2013. Generalized Linear Models (GLMs) revealed that the distance travelled from the nest was significantly related to temperature, but also to the time of day and the age of chicks. Temperature also had a significant positive influence on flight altitude and the latter on flight speed. The Resource Utilization Function (RUF) showed significant resource use in locations close to water (rivers and water bodies) and also in agricultural areas, preferably close to urban areas and rivers. On the other hand, unlike in other areas of Spain, the use of the edges between forest and agricultural areas and forest areas themselves showed negative coefficients with values not significant, perhaps related to changes in prey availability in the traditional hunting grounds.

Impacts of Mesquite Distribution on Seasonal Space Use of Lesser Prairie-Chickens

Loss of native grasslands by anthropogenic disturbances has reduced availability and connectivity of habitat for many grassland species. A primary threat to contiguous grasslands is the encroachment of woody vegetation, which is spurred by disturbances that take on many forms from energy development, fire suppression, and grazing. These disturbances are exacerbated by natural- and human-driven cycles of changes in climate punctuated by drought and desertification conditions. Encroachment of honey mesquite (Prosopis glandulosa) into the prairies of southeastern New Mexico has potentially limited habitat for numerous grassland species, including lesser prairie-chickens (Tympanuchus pallidicinctus). To determine the magnitude of impacts of distribution of mesquite and how lesser prairie-chickens respond to mesquite presence on the landscape in southeastern New Mexico, we evaluated seasonal space use of lesser prairie-chickens in the breeding and nonbreeding seasons. We derived several remotely sensed spatial metrics to characterize the distribution of mesquite. We then used these data to create population-level resource utilization functions and predict intensity of use of lesser prairie-chickens across our study area. Home ranges were smaller in the breeding season compared with the nonbreeding season; however, habitat use was similar across seasons. During both seasons, lesser prairie-chickens used areas closer to leks and largely avoided areas with mesquite. Relative to the breeding season, during the nonbreeding season habitat use suggested a marginal increase in mesquite within areas of low intensity of use, yet aversion to mesquite was strong in areas of medium to high intensity of use. To our knowledge, our study is the first to demonstrate a negative behavioral response by lesser prairie-chickens to woody encroachment in native grasslands. To mitigate one of the possible limiting factors for lesser prairie-chickens, we suggest future conservation strategies be employed by land managers to reduce mesquite abundance in the southern portion of their current range.

Habitat Use and Selection by Giant Pandas

Animals make choices about where to spend their time in complex and dynamic landscapes, choices that reveal information about their biology that in turn can be used to guide their conservation. Using GPS collars, we conducted a novel individual-based analysis of habitat use and selection by the elusive and endangered giant pandas (Ailuropoda melanoleuca). We constructed spatial autoregressive resource utilization functions (RUF) to model the relationship between the pandas' utilization distributions and various habitat characteristics over a continuous space across seasons. Results reveal several new insights, including use of a broader range of habitat characteristics than previously understood for the species, particularly steep slopes and non-forest areas. We also used compositional analysis to analyze habitat selection (use with respect to availability of habitat types) at two selection levels. Pandas selected against low terrain position and against the highest clumped forest at the at-home range level, but no significant factors were identified at the within-home range level. Our results have implications for modeling and managing the habitat of this endangered species by illustrating how individual pandas relate to habitat and make choices that differ from assumptions made in broad scale models. Our study also highlights the value of using a spatial autoregressive RUF approach on animal species for which a complete picture of individual-level habitat use and selection across space is otherwise lacking.

Habitat selection and use by sympatric, translocated greater sage‐grouse and Columbian sharp‐tailed grouse

ABSTRACTGreater sage‐grouse (Centrocercus urophasianus) and Columbian sharp‐tailed grouse (Tympanuchus phasianellus columbianus) have declined substantially in Washington, USA, primarily because native shrub‐steppe has been converted to agriculture. In response, state and federal agencies have acquired and restored habitat, and augmented and reintroduced grouse to suitable areas. We examined how sympatric, translocated sage‐grouse and sharp‐tailed grouse used space and selected habitats within their spring–summer home ranges and at nest sites within remnant shrub‐steppe surrounded by a matrix of cropland in eastern Washington. Because their life‐history requirements differ, we expected extensive habitat partitioning between species. Using radiolocations of ≥43 birds of each species, we found that sage‐grouse had larger spring–summer home ranges than sharp‐tailed grouse, and the composite of home ranges for sharp‐tailed grouse fell almost completely within the composite of home ranges for sage‐grouse. By creating resource utilization function models using radiolocations of ≥53 birds of each species, we found that areas of highest predicted intensity of use for both species overlapped by &gt;50%, even at the top 5% quantile. Both species used restored fields and areas farther from trees and roads or distribution lines more intensely. Sage‐grouse used less rugged areas more intensely, and both species used 3 levels of shrub cover equally. To compare selection of nest sites relative to available sites for nesting in both species, we created resource selection function models for ≥30 birds of each species and found that sage‐grouse selected areas farther from distribution lines, whereas sharp‐tailed grouse selected restored fields. When we examined vegetation characteristics used by female sage‐grouse and sharp‐tailed grouse at nest sites using a case‐control, use versus non‐use design for ≥26 birds of each species, we found sage‐grouse used areas with greater shrub cover, lower annual forb cover, and taller perennial grasses, whereas sharp‐tailed grouse used areas with greater perennial grass cover and taller perennial grasses and forbs. When we compared habitat features measured at nest sites between species, we found sage‐grouse used areas with greater moderate and dense shrub cover, lower sparse shrub cover, less restored fields, higher patch diversity, and areas farther from distribution lines than sharp‐tailed grouse. These differences resulted in only 38% overlap of areas within the top quartile of relative selection values for nest sites by the 2 species, and &lt;10% at the top 5% quantile. Because many western states are highly fragmented by cropland, understanding how populations of species with different life‐history characteristics, such as sage‐grouse and sharp‐tailed grouse, coexist within remaining tracts of shrub‐steppe at different spatial scales is important for effectively conserving and managing shrub‐steppe communities. © 2015 The Wildlife Society.