Global Positioning System Location Data Research Articles

Feasibility and acceptability of mobile methods to assess home and neighborhood environments related to adolescent sleep

ObjectiveA growing evidence base suggests home and neighborhood environmental exposures may influence adolescent sleep, but few studies have assessed these relationships using methods that account for time-varying, location-specific exposures, or multiple neighborhood contexts. This study aimed to assess the feasibility and acceptability of using smartphone global positioning system (GPS) tracking and ecological momentary assessment (EMA) to assess time-varying home and neighborhood environmental exposures hypothesized to be associated with adolescent sleep. MethodsAdolescents aged 15-17 years in Philadelphia completed 7 days of continuous smartphone GPS tracking, which was used to identify daily levels of exposure to geocoded neighborhood factors (eg, crime, green space). Four daily EMA surveys assessed home sleep environment (eg, noise, light), stress, health behaviors, and neighborhood perceptions. Feasibility and acceptability of GPS tracking and EMA were assessed, and distributions of daily environmental exposures were examined. ResultsAmong 25 teens (mean age 16, 56% male), there was a high level of GPS location data captured (median daily follow-up: 24 hours). Seventy-eight percent of EMA surveys were completed overall. Most participants (96%) reported no privacy concerns related to GPS tracking and minimal burden from EMA surveys. Exposures differed between participants’ home neighborhoods and locations visited outside the home neighborhood (eg, higher crime away from home). Sleep environment disruptions were present on 29% of nights (most common: uncomfortable temperature) and were reported by 52% of adolescents. ConclusionsResults demonstrate the feasibility and acceptability of mobile methods for assessing time-varying home and neighborhood exposures relevant to adolescent sleep for up to 1 week.

Multi‐model application informs prey composition of mountain lions Puma concolor

Global positioning system (GPS) receivers allow researchers to collect location data that provide information about fine-scale animal movements. For large carnivores, these data are routinely processed to identify clusters of GPS locations which are investigated to validate feeding sites, estimate prey species composition and model the likelihood of predation events based on characteristics of GPS location data within clusters. Although developing predation models entails a high level of field effort, researchers are apprehensive in applying system-specific models to other systems both spatially and temporally. Our objectives were to apply and compare multiple predation models to predict and identify feeding events outside of the geographic areas where models were developed. Using our multi-model approach, we identified feeding sites and estimated kill rates and prey composition of mountain lions Puma concolor in southwest Wyoming, USA from 2017 to 2019. Our approach increased our field efficiency by reducing potential field site investigations by 63%. We provide results of estimated diet composition in our study area where mountain lion prey included relatively high proportions of pronghorn (12.3%) and smaller mammals, particularly coyotes (7.6%). We also provide a comparison of the predation models developed across unique ecoregions of North America, and how they performed when applied to our area. We believe a similar approach could be adopted for other large carnivore populations where multiple models have been developed to characterize feeding events.

Multi-scale habitat selection and spatial analysis reveals a mismatch between the wintering distribution of a threatened population of Taiga Bean Geese Anser fabalis and its protected area

ABSTRACT Capsule Our multi-scale habitat selection and spatial analysis of a threatened population of Taiga Bean Geese Anser fabalis highlights the importance of monitoring and review programmes to determine whether species conservation measures are being implemented at the correct spatio-temporal scales. Aims To undertake a habitat selection and spatial analysis of an internationally important population of Taiga Bean Geese, and quantify the extent to which their foraging range overlaps with a protected area classified to protect their roost sites and foraging areas. Methods A five-year field count dataset was used to quantify foraging habitat selection at the population range scale. In addition, global positioning system (GPS)/ultra high frequency loggers were attached to 12 birds and GPS location data were collected to quantify foraging habitat selection at an individual foraging range scale. Results Generalized linear models predicted that, at the population foraging range scale, Taiga Bean Geese selected agriculturally improved pasture, and this selection was more pronounced at greater distances from public roads. At an individual foraging range scale, compositional analysis revealed that agriculturally improved pasture was significantly selected over all other habitats. There was a substantial mismatch between their individual foraging ranges and the protected area, with less than 35% (median: 21%; range 9.5–31.9%) of their individual full foraging ranges overlapping with the protected area. Discussion Fixed protected areas may fail to fully accommodate the spatio-temporal foraging dynamics of geese, however a more appropriate conservation measure may be the use of flexible management schemes to maintain their foraging areas within and beyond protected area boundaries. This case study highlights the importance of developing dynamic conservation strategies for species liable to undergo range shifts.

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.

Sex‐Specific Behaviors of Hunted Mule Deer During Rifle Season

ABSTRACTAnimal populations face increased threats to mobility and access to critical habitat from a variety of human disturbances including roads, residential development, agriculture, and energy development. Disturbance from human hunting is known to alter habitat use in ungulates, but recent work suggests that hunting may also trigger the onset of migration. Whether this holds true across ungulate species and hunting systems warrants further empirical testing. We used global positioning system location data from mule deer (Odocoileus hemionus) in south‐central Wyoming, USA, to evaluate the sex‐specific effects of hunting on habitat selection and migratory behavior from 2016 to 2018. We modeled habitat selection before and during hunting season using a step selection function, and we used time‐to‐event models to evaluate if hunting triggered migration. We found habitat selection and migration timing to be sex specific. Males responded to hunting season by selecting security habitat away from motorized routes, whereas females used habitat through hunting season that retained higher forage quality. Weather, as indexed by temperature and precipitation (i.e., snowfall), influenced migration timing for males and females. Migration timing in males was influenced by migration distance, where individuals traveling >50 km tended to migrate earlier than individuals moving <50 km. For deer that survived to rifle season, hunting was less influential on migration timing than environmental factors. Rifle season increased the likelihood of migration by 2% in females and <0.01% in males compared to outside rifle season. Our findings suggest that roadless areas on mule deer summer ranges and within migration corridors reduce the effects of hunting disturbance. Consequently, managers may consider limiting the use of motorized vehicles as a method for reducing effects on migration from hunting disturbance. © 2020 The Wildlife Society.

Genetic Optimized Location Aided Routing Protocol for VANET Based on Rectangular Estimation of Position

Vehicle Ad-Hoc Network (VANET) is a dynamic decentralized network that consists of various wireless mobile vehicles with no individual user management. Several routing protocols can be used for VANETs, for example, the Location-Aided Routing (LAR) protocol that utilizes location information provided by the Global Positioning System (GPS) sensors. It can help to reduce the search space for the desired route—limiting the search space results in fewer route discovery messages. However, two essential aspects are ignored while applying the LAR protocol in the VANET-based environment. Firstly, the LAR does not exploit the fact that nodes in VANET do not have pure random movement. In other words, nodes in LAR predict the position of destination node by ignoring the fact that the pre-defined constraint on the destination node navigation is met. Secondly, the nodes in the conventional LAR (or simply stated as LAR) protocol use the location information of the destination node before selecting the route location, which is most likely to expire because of the fast movement of the nodes in the VANET environment. This study presents an estimation based on a heuristic approach that was developed to reject weak GPS location data and accept accurate ones. The proposed routing protocol stated as Rectangle-Aided LAR (RALAR) is based on a moving rectangular zone according to the node′s mobility model. Additionally, the proposed RALAR protocol was optimized by using the Genetic Algorithm (GA) by selecting the most suitable time-out variable. The results were compared with LAR and Kalman-Filter Aided-LAR (KALAR), the most commonly utilized protocols in VANET for performance metrics using Packet Delivery Ratio (PDR), average End-to-End Delay (E2E Delay), routing overhead and average energy consumption. The results showed that the proposed RALAR protocol achieved an improvement over the KALAR in terms of PDR of 4.7%, average E2E delay of 60%, routing overhead of 15.5%, and 10.7% of energy consumption. The results proved that the performance of the RALAR protocol had outperformed the KALAR and LAR protocol in terms of regular network performance measures in the VANET environment.

Identification of carnivore kill sites is improved by verified accelerometer data

BackgroundQuantifying kill rates is central to understanding predation ecology. However, estimating kill rates and prey composition in carnivore diets is challenging due to their low densities and cryptic behaviors limiting direct observations, especially when the prey is small (i.e., < 5 kg). Global positioning system (GPS) collars and use of collar-mounted activity sensors linked with GPS data can provide insights into animal movements, behavior, and activity.MethodsWe verified activity thresholds for American black bears (Ursus americanus), a bobcat (Lynx rufus), and wolves (Canis spp.) with GPS collars containing on-board accelerometers by visual observations of captive individuals’ behavior. We applied these activity threshold values to GPS location and accelerometer data from free-ranging carnivores at locations identified by a GPS cluster algorithm which we visited and described as kill sites or non-kill sites. We then assessed use of GPS, landscape, and activity data in a predictive model for improving detection of kill sites for free-ranging black bears, bobcats, coyotes (C. latrans), and wolves using logistic regression during May–August 2013–2015.ResultsAccelerometer values differed between active and inactive states for black bears (P < 0.01), the bobcat (P < 0.01), and wolves (P < 0.01). Top-performing models of kill site identification for each carnivore species included activity data which improved correct assignment of kill sites by 5–38% above models that did not include activity. Though inclusion of activity data improved model performance, predictive power was less than 45% for all species.ConclusionsCollar-mounted accelerometers can improve identification of predation sites for some carnivores as compared to use of GPS and landscape informed covariates alone and increase our understanding of predator–prey relations.

Nocturnal flights by Bearded Vultures Gypaetus barbatus detected for the first-time using GPS and accelerometer data

ABSTRACT Capsule: We document previously undescribed nocturnal flight behaviour by Bearded Vultures Gypaetus barbatus using a combination of accelerometer and global positioning system (GPS) information. Aims: To study the nocturnal flight activity of the Bearded Vulture and determine whether nocturnal flights could be linked to foraging behaviour. Methods: We used both accelerometer and GPS location data of 11 Bearded Vultures in the Spanish Pyrenees along with 88 carcasses monitored with camera traps. Results: Over half (55%, n = 11) of the individuals tracked were recorded flying between 0.7 and 6.1 km on at least 19 different nights, including 37% that occurred when less than 20% of the moon was illuminated. Bearded Vultures displayed feeding activity in only 8.2% of the 146 feeding events existing during the hour after dawn and the hour before dusk. Conclusions: Our findings suggest that foraging benefits do not explain the nocturnal flights. Disturbances or adverse weather conditions may result in the abandonment of an overnight roosting site. This could also explain why individuals recovered in the field showed impact injuries.

Hiding Without Cover? Defining Elk Security in a Beetle‐Killed Forest

ABSTRACTRecent mountain pine beetle (Dendroctonus ponderosae; pine beetle) outbreaks in the western United States have affected nearly 18 million ha of pine (Pinus spp.) forest and are unprecedented in spatial extent, severity, and duration, yet little is known about wildlife responses to large‐scale insect outbreaks. Elk (Cervus canadensis) are important wildlife whose dominant management paradigm on public lands has focused on providing security habitat to increase survival during hunting seasons and to maintain elk presence on public lands to promote hunter opportunity. To assess the effect of pine beetles and associated changes in forest structure on elk security, we used a time series to characterize canopy cover pre‐ and post‐pine beetle outbreak, characterized relative canopy cover among the dominant forest types in the study area post‐pine beetle outbreak, and used global positioning system location data from male and female elk to define habitat relationships and security during the archery and rifle hunting seasons. Our study area was within the Elkhorn Mountains of southwest Montana, USA, 2015–2017, which experienced 80% mortality of lodgepole pine (Pinus contorta) forests during a pine beetle outbreak that peaked in 2008. We observed an 8.5% reduction in canopy cover within pine beetle‐infested lodgepole pine forests, yet canopy cover remained relatively high among other forest types post‐outbreak. The top‐ranked habitat security models contained positive relationships with canopy cover, distance to motorized routes, terrain ruggedness, and slope with few notable differences among sexes and seasons. Across sexes and seasons, 75% and 50% of elk use was within areas with average canopy cover values ≥31 ± 6.65 (SD)% and ≥53 ± 5.7% that were an average of ≥2,072 ± 187.93 m and ≥3,496 ± 157.32 m from a motorized route, respectively. Therefore, we recommend fall elk security be defined as areas that meet these criteria for minimum canopy cover and distance from motorized routes in the Elkhorn Mountains and in other landscapes with similar forest characteristics and hunting pressures. Although we observed expected reductions in canopy cover within pine beetle‐infested forests, defoliation alone did not appear to negatively affect elk security or reduce canopy cover below our management recommendations. Nonetheless, because of the prevalence of standing dead trees in our study area, we recommend future work that investigates the relationships with pine beetle‐infested areas post‐blowdown because changes in ground structure and costs of locomotion may affect elk habitat and security. © 2019 The Authors. Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.

Characteristics of Wolverine (&lt;i&gt;Gulo gulo&lt;/i&gt;) dens in the lowland boreal forest of north-central Alberta

We investigated Wolverine (Gulo gulo) denning ecology in the boreal forest of northern Alberta. During winters 2015/2016 and 2016/2017, we used live traps to capture four female Wolverines and fitted them with global positioning system (GPS) collars programmed to take a location every two hours. We determined reproductive status at capture and GPS location data were used to identify den sites. One female denned in one of the two years, one female denned in two consecutive years, and two females did not den during the study. Seven of the eight Wolverine den sites were in mature or old Black Spruce (Picea mariana) stands, where dens consisted of a hollow, moss-covered mound originating from a partially uplifted root mass caused by a leaning or fallen tree. One den was located under decayed logging debris with an overstorey dominated by dense deciduous regeneration. Maximum snow depth recorded (December–March) at weather stations in the study area was 32–51 cm. Spring snow coverage was scarce in our study area (&lt;1%) and always associated with ice cover on lakes and large ponds; mean distance from dens to nearest spring snow coverage was 15.19 km (SD = 2.73, n = 8). Female Wolverines appear to be using locally-available denning structures in the lowland boreal forest, despite a lack of deep snow, persistent spring snow cover, or large boulders documented in other studies. 

Machine learning for inferring animal behavior from location and movement data

Movement ecology has rapidly advanced owing to recent developments of animal-attached devices and wide applications of sophisticated statistical and machine learning techniques in analysis of animal movement data. Global Positioning System (GPS) transmitters used for estimating animal locations and tri-axial accelerometers used for measuring the 3-dimensional accelerations of animal's motion aid researchers in collecting location and locomotion data at fine spatial and temporal scales. Machine learning and other advanced statistical methods bridge conceptual models to data, providing insights into ecological and physiological mechanisms underlying animal behavior and movements. This study reviews the general principles and applications of state space models, hidden Markov models, random forests, and support vector machines in the inference of animal behavior from movement data. Unsupervised learning algorithms, including Bayesian state space models implemented for robust correlated random walk models and hidden Markov models, help infer different behavioral modes using GPS location data. State space models can account for measurement error in GPS locations and estimate the true locations of animals; however, without including movement-state switching, state space models do not infer behavioral modes directly. On the contrary, hidden Markov models estimate the probabilities that animals switch between different behavioral modes. Nevertheless, hidden Markov models neither directly estimate animal locations nor account for measurement error explicitly. Supervised learning algorithms integrate data on locations and directional accelerations with synchronized behavioral observations (i.e., labels) to classify behaviors to pre-defined behavioral categories. Unlike unsupervised learning, supervised learning requires behavioral observations to label locations and accelerometer data to train the learning algorithms. However, behavioral observations synchronized with relocations and acceleration records are often missing or unattainable in many species, hindering the applications of supervised learning, making unsupervised learning a suitable tool for behavioral annotation of movement paths in secretive (cryptic) or less studied species. Environmental and behavioral annotations of animal movement paths by machine learning improve understanding the effects of environmental conditions on animal movements and behavioral decisions.

Are Lek Disturbance Buffers Equitable for All Gunnison Sage-Grouse Populations?

Abstract Lek disturbance buffers can be used to identify areas that provide important seasonal habitat for Gunnison sage grouse Centrocercus minimus (hereafter GUSG), a species with declining or vulnerable populations across their range. Lek disturbance buffers define areas around leks where anthropogenic disturbance is not permitted and have been considered for potential conservation strategies across GUSG habitat. Currently there is minimal information available on the effectiveness of the size of defined lek disturbance buffers. This study focused on two GUSG populations, the smaller Crawford population and a segment of the larger Gunnison Basin population. We utilized global positioning system location data on GUSG to evaluate seasonal use within three lek disturbance buffers, then compared and contrasted results between the two populations. The Crawford GUSG population showed increased movements from breeding season to late brood-rearing season and in winter returned to a usage pattern similar to the breeding season. Comparatively, the western Gunnison Basin GUSG population showed considerable movement throughout the entire year. In addition to these differences, we noted remarkable differences in distance between active leks, home range size, and total daily distance traveled between Crawford and western Gunnison Basin populations. Lek disturbance buffers created using the standard protocol provided varying protection depending on the distance between leks and number of leks. In small populations, the disturbance buffers overlapped each other, thus producing a smaller total lek disturbance buffer area. In addition to adding to the general body of knowledge of a little-studied species, our study had two important findings: 1) the use of empirical cumulative distribution demonstrated considerable differences in lek disturbance buffer use between the Crawford and the western Gunnison Basin populations, and 2) lek disturbance buffers did not provide equal protection for all populations on the basis of their current definition and derivation. We anticipate that land managers will find our results useful and informative when developing land management plans for the conservation of GUSG. Our analysis showed that the variability between populations and species is important for managers to consider when developing conservation strategies, especially for small populations.

Vehicle location measurement method for radio-shadow area through iBeacon message

Information communication technology related vehicle services need to support location and the transmission of communication and traffic information between vehicles, or between vehicles and infrastructure. In particular, the technology for the measurement of the accurate location of a vehicle is dependent on location-determination technology like Global Positioning System, and this technology is very important for vehicle driving and location services. If, however, a vehicle is in a Global Positioning System radio-shadow area, neither a Global Positioning System nor a Differential Global Positioning System can accurately measure the corresponding location because of a high error rate caused by the shadowing intervention. Even an Inertial Measurement Unit could provide inaccurate location data due to sensor drift faults around corners and traffic-road speed dumps. Vehicles, therefore, need an absolute location to prevent the provision of inaccurate vehicle-location data that is due to radio-shadow areas and relational Inertial Measurement Unit positions. To achieve this, we assume that vehicle-to-infrastructure communication is possible between a vehicle and roadside unit in Vehicular Ad hoc Networks. We used iBeacon at the roadside unit and revised its Universally Unique Identifier so that it generates absolute Global Positioning System location data; that is, moving vehicles can receive absolute Global Positioning System data from the roadside unit-based iBeacon. We compared the proposed method with current Global Positioning System and Inertial Measurement Unit systems for the following two cases: one with a radio-shadow area and one without. We proved that the proposed method generates location data that are more accurate than those of the other methods.

Security areas for elk during archery and rifle hunting seasons

ABSTRACTFall elk (Cervus canadensis) habitat management on public lands provides security areas for reasonable elk survival and hunter opportunity. The management focus of maintaining or improving security areas, combined with conservative harvest regulations, may explain why some elk populations have increased in the western United States. However, in areas that include lands that restrict public hunter access, elk may alter their space use patterns during the hunting season by increasing use of areas that restrict public hunter access rather than using security areas on adjacent public lands. We used global positioning system location data from 325 adult female elk in 9 southwest Montana populations to determine resource selection during the archery and rifle hunting seasons. We found that during the archery season, in order of decreasing strength of selection, elk selected for areas that restricted access to public hunters, had greater time‐integrated normalized difference vegetation index values, had higher canopy cover, were farther from motorized routes, and had lower hunter effort. During the rifle season, in order of decreasing strength of selection, elk selected for areas that restricted access to public hunters, were farther from motorized routes, had higher canopy cover, and had higher hunter effort. Interactions among several covariates revealed dependencies in elk resource selection patterns. Further, cross‐population analyses revealed increased elk avoidance of motorized routes with increasing hunter effort during both the archery and rifle hunting seasons. We recommend managing for areas with ≥13% canopy cover that are ≥2,760 m from motorized routes, and identifying and managing for areas of high nutritional resources within these areas to create security areas on public lands during archery season. During the rifle season, we recommend managing for areas with ≥9% canopy cover that are ≥1,535 m from motorized routes, and are ≥20.23 km2. Lastly, given increased elk avoidance of motorized routes with higher hunter effort, we recommend that to maintain elk on public lands, managers consider increasing the amount of security in areas that receive high hunter effort, or hunting seasons that limit hunter effort in areas of high motorized route densities. © 2017 The Authors. Journal of Wildlife Management Published by Wiley Periodicals, Inc.

Use of GPS tags to describe the home ranges, migration routes, stop-over locations and breeding area of Taiga Bean Geese Anser fabalis fabalis wintering in central Scotland

ABSTRACTCapsule: Taiga Bean Geese Anser fabalis fabalis wintering near Falkirk, Scotland staged in Denmark, Norway and Sweden and summered in central Sweden.Aims: To determine the migration routes, timing of movements, breeding area and home ranges of Taiga Bean Geese wintering near Falkirk, Scotland.Methods: Ten Taiga Bean Geese, caught on the wintering grounds in Scotland, were marked with neck collars carrying global positioning system (GPS) tags. A further 21 geese were fitted with individually marked plastic neck collars. GPS location data were collected and field counts and searches for individually marked geese were undertaken to provide detailed information on their location throughout the year.Results: Seven GPS tags provided information away from Scotland, indicating that two migration routes were used en route to the breeding grounds in Dalarna, Sweden. During the non-breeding season, the total home range of the geese was approximately 466 km2, although the total area within agricultural fields used by the geese may have been as small as 13 km2.Conclusions: The timing of movements, migration routes, breeding area and identification of important stop-over sites for this wintering population are described for the first time.

Reduction of GPS Latency Using RTK GPS/GNSS Correction and Map Matching in a Car NavigationSystem

The difference between definition time of GPS (Global Positioning System) position data and actual display time of car positions on a map could reduce the accuracy of car positions displayed in PND (Portable Navigation Device)-type CNS (Car Navigation System). Due to the time difference, the position of the car displayed on the map is not its current position, so an improved method to fix these problems is required. It is expected that a method that uses predicted future positionsto compensate for the delay caused by processing and display of the received GPS signals could mitigate these problems. Therefore, in this study an analysis was conducted tocorrect late processing problems of map positions by mapmatching using a Kalman filter with only GPS position data anda RRF (Road Reduction Filter) technique in a light-weight CNS. The effects on routing services are examined by analyzing differences that are decomposed into along and across the road elements relative to the direction of advancing car. The results indicate that it is possible to improve the positional accuracy in the along-the-road direction of a light-weight CNS device that uses only GPS position data, by applying a Kalman filter and RRF.

Evaluating distributional shifts in home range estimates.

A variety of methods are commonly used to quantify animal home ranges using location data acquired with telemetry. High-volume location data from global positioning system (GPS) technology provide researchers the opportunity to identify various intensities of use within home ranges, typically quantified through utilization distributions (UDs). However, the wide range of variability evident within UDs constructed with modern home range estimators is often overlooked or ignored during home range comparisons, and challenges may arise when summarizing distributional shifts among multiple UDs. We describe an approach to gain additional insight into home range changes by comparing UDs across isopleths and summarizing comparisons into meaningful results. To demonstrate the efficacy of this approach, we used GPS location data from 16 bighorn sheep (Ovis canadensis) to identify distributional changes before and after habitat alterations, and we discuss advantages in its application when comparing home range size, overlap, and joint-space use. We found a consistent increase in bighorn sheep home range size when measured across home range levels, but that home range overlap and similarity values decreased when examined at increasing core levels. Our results highlight the benefit of conducting multiscale assessments when comparing distributions, and we encourage researchers to expand comparative home range analyses to gain a more comprehensive evaluation of distributional changes and to evaluate comparisons across home range levels.

Experimental Flights Using a Small Unmanned Aircraft System for Mapping Emergent Sandbars

The US Geological Survey and Parallel Inc. conducted experimental flights with the Tarantula Hawk (T-Hawk) unmanned aircraft system ( uas ) at the Dyer and Cottonwood Ranch properties located along reaches of the Platte River near Overton, Nebraska, in July 2013. We equipped the T-Hawk uas platform with a consumer-grade digital camera to collect imagery of emergent sandbars in the reaches and used photogrammetric software and surveyed control points to generate orthophotographs and digital elevation models ( dems ) of the reaches. To optimize the image alignment process, we retained and/or eliminated tie points based on their relative errors and spatial resolution, whereby minimizing the total error in the project. Additionally, we collected seven transects that traversed emergent sandbars concurrently with global positioning system location data to evaluate the accuracy of the uas survey methodology. The root mean square errors for the elevation of emergent points along each transect across the dems ranged from 0.04 to 0.12 m. If adequate survey control is established, a uas combined with photogrammetry software shows promise for accurate monitoring of emergent sandbar morphology and river management activities in short (1–2 km) river reaches.

Grizzly bear and human interaction in Yellowstone National Park: An evaluation of bear management areas

ABSTRACTWildlife managers often rely on permanent or temporary area closures to reduce the impact of human presence on sensitive species. In 1982, Yellowstone National Park created a program to protect threatened grizzly bears (Ursus arctos) from human disturbance. The bear management area (BMA) program created areas of the park where human access was restricted. The program was designed to allow unhindered foraging opportunities for bears, decrease the risk of habituation, and provide safety for backcountry users. The objective of our study was to evaluate human‐bear interaction in BMAs and determine if they were effective. We used human and grizzly bear global positioning system location data to study 6 of 16 BMAs from 2007 to 2009. We contrasted data when BMAs were unrestricted (open human access) and restricted (limited human access). We used location data collected when BMAs were unrestricted to delineate a human recreation area (HRA) and determined a daily human active and inactive period. We applied the HRA and daily activity times to bear location data and evaluated how bear movement behavior changed when people were present and absent. We found that grizzly bears were twice as likely to be within the HRA when BMAs were restricted. We also found that grizzly bears were more than twice as likely to be within the HRA when BMAs were unrestricted, but people were inactive. Our results suggest that human presence can displace grizzly bears if people are allowed unrestricted access to the 6 BMAs in our study. Our study provides evidence for the utility of management closures designed to protect a threatened species in a well‐visited park. Our approach can be reapplied by managers interested in balancing wildlife conservation and human recreation. © 2013 The Wildlife Society.

A Global Positioning System guided automated rice transplanter

We have developed a new Global Positioning System (GPS) guided rice transplanter. We developed GPS and IMU guided rice transplanter in previous researches. Those were guided with GPS position data and inertia measurement unit (IMU) direction data. New one is guided with GPS position data with tilt correction during straight driving and guided with IMU direction data during turning at the headland. The GPS antenna is set to 1.5m height and 0.4m front offset from vehicle front axle. The actuator control command and data communication protocols comply with through the controller area network (CAN) bus. Steering and transmission are controlled by electrical actuators according to the location in a field. We report results of experiment.