1,747 research outputs found

    A multi-method approach to delineate and validate migratory corridors

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    Context: Managers are faced with numerous methods for delineating wildlife movement corridors, and often must make decisions with limited data. Delineated corridors should be robust to different data and models. Objectives: We present a multi-method approach for delineating and validating wildlife corridors using multiple data sources, which can be used conserve landscape connectivity. We used this approach to delineate and validate migration corridors for wildebeest (Connochaetes taurinus) in the Tarangire Ecosystem of northern Tanzania. Methods: We used two types of locational data (distance sampling detections and GPS collar locations), and three modeling methods (negative binomial regression, logistic regression, and Maxent), to generate resource selection functions (RSFs) and define resistance surfaces. We compared two corridor detection algorithms (cost-distance and circuit theory), to delineate corridors. We validated corridors by comparing random and wildebeest locations that fell within corridors, and cross-validated by data type. Results: Both data types produced similar RSFs. Wildebeest consistently selected migration habitat in flatter terrain farther from human settlements. Validation indicated three of the combinations of data type, modeling, and corridor detection algorithms (detection data with Maxent modeling, GPS collar data with logistic regression modeling, and GPS collar data with Maxent modeling, all using cost-distance) far outperformed the other seven. We merged the predictive corridors from these three data-method combinations to reveal habitat with highest probability of use. Conclusions: The use of multiple methods ensures that planning is able to prioritize conservation of migration corridors based on all available information

    Wolf, Canis lupus, Pup Mortality: Interspecific Predation or Non-Parental Infanticide?

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    A breeding male Gray Wolf, Canis lupus, equipped with a GPS collar was documented going to the den site of another Gray Wolf pack. This trip was coincident with an attack on the den of the other pack and the occurrence of a dead and partially consumed Gray Wolf pup at the same location. We present two possible explanations - interspecific predation and non-parental infanticide - to account for this observation. Because the Gray Wolf with the GPS collar and his mate were first-time breeders and were attempting to establish a territory space of their own, we speculate that, based on the available evidence, this observation most likely represents a case of non-parental infanticide that fits the predictions of the resource competition hypothesis

    Suitability of a GPS Collar for Grazing Studies

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    The traditional means of tracking animal location in a field is by visual observation. Not only is this method labor intensive, it is also prone to error as the observer can alter cattle movement, observation periods are often too short to obtain confidence in general daily behavior patterns, and observer fatigue becomes an issue. In the 1990s, the University of Kentucky began using GPS collars on cattle to track their position with the goal of incorporating this information into cattle management practices. One of the key unanswered questions regarding the GPS collars is the accuracy of the position data recorded by the collar. The objective of this work was to assess the capabilities and limitations of using GPS collars to track animal movement in grazed watersheds. Static tests were conducted in an open field, under trees, and near fence lines to ascertain the impacts of various field features on collar performance. Dynamic tests were carried out to examine the errors associated with the collars while operated under real-world conditions. Results from these tests indicate that the collars generally provide data with horizontal accuracies of 4 to 5 m. This information will assist researchers in the development of experiments based on collar capabilities and limitations

    DEVELOPMENT OF A SYSTEM FOR COLLECTION OF POSITIONAL-BASED DATA FOR HORSES

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    Data gathering is a crucial part in many Equitation Science related projects, and this can be a very resource-intensive and time-consuming process. This project aimed to develop a tool to aid Equitation Science researchers in gathering positional-based data of horses. A prototype data collection system was developed, designed to enable cost-effective data acquisition, storage and presentation. The prototype system includes a GPS-enabled collar for collection of positional data, as well as a platform for presenting the gathered data online. Interviews were conducted with Equitation Science researchers in order to determine the requirements of such a system and to ensure that data obtained would be of sufficient quality. The GPS collar developed incorporates a microcontroller which allows tracking of horses within one metre. Furthermore, it is possible to extend the capabilities of the device using appropriate hardware to gather different types of equine data. The data gathered by the GPS collar are uploaded to a server where data are stored in a relational database ready for access by the scientist via a graphical user interface using a dedicated website. The user interface was developed using commonly practised interaction design methods such as user studies, heuristic evaluation and cognitive walkthroughs to ensure a user-friendly experience. Equitation Science experts contributed to both the design of the systems software in addition to the design and placement of the collar. It is anticipated that the GPS collar system can be used in Equitation Science projects that require identification of movement patterns of both individual horses as well as groups of horses, and will be able to provide measures such as distance moved and speed of movement. The system is designed to be future proof and able to be easily adapted according to the requirements of specific studies. For the Equitation Scientist in practice, the system provides the possibility to collect objective data from horses’ activities by removing the effect of the potentially biased human observer, and might thereby improve the quality of the conclusions in the scientific study. Lay person message: An electronic system has been developed to simplify the collection of positional-based data for equine research. The system consists of a GPS collar which collects data from horses and associated software accessed through a website for analysing and presenting the data. The system can be used in many different types of horse-based projects and will allow more objective data to be collected that can be used to understand horses and to improve horse welfare by removing the effect of the potentially biased human observer

    Spatial and Temporal Habitat Use of an Asian Elephant in Sumatra

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    Increasingly, habitat fragmentation caused by agricultural and human development has forced Sumatran elephants into relatively small areas, but there is little information on how elephants use these areas and thus, how habitats can be managed to sustain elephants in the future. Using a Global Positioning System (GPS) collar and a land cover map developed from TM imagery, we identified the habitats used by a wild adult female elephant (Elephas maximus sumatranus) in the Seblat Elephant Conservation Center, Bengkulu Province, Sumatra during 2007–2008. The marked elephant (and presumably her 40–60 herd mates) used a home range that contained more than expected medium canopy and open canopy land cover. Further, within the home range, closed canopy forests were used more during the day than at night. When elephants were in closed canopy forests they were most often near the forest edge vs. in the forest interior. Effective elephant conservation strategies in Sumatra need to focus on forest restoration of cleared areas and providing a forest matrix that includes various canopy types

    Effects of Roads on Black Bear Distribution in Southern Vermont

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    The American black bear (Ursus americanus) is a wide-ranging, large carnivore species that makes use of multiple habitat types throughout the year. In the northeastern US, black bears require large areas of relatively undisturbed forest and avoid development, such as urban and suburban areas. Roads represent another form of development that may affect the distribution of bears. However, the effects of roads remain largely unknown and represent a potential conservation concern. We sought to determine the relationship between roads and distribution of black bears in a forested region of southern Vermont. We examined the probability of occurrence of black bears using GPS-collar data (n = 30,179 locations) collected from a marked population of bears (n = 8 females, 15 males) from 2011 to 2014. We then constructed a set of 7 candidate models to explain occupancy that included combinations of three road types: secondary, vehicular, and local. Model selection techniques were used to determine the best model in the set. Models were performed separately for male and female bears, which have been shown to exhibit different distribution patterns elsewhere. The top model for each sex was the most complex in the set, and included the additive combination of all three road types. For males, vehicular and local roads positively affected occupancy, whereas secondary roads had a negative influence on occupancy. For females, vehicular and secondary roads positively affected occupancy, whereas local roads negatively affected occupancy. Our results indicate that small, low traffic, residential and ATV roads influence bear distribution; most likely by providing easy pathways to travel through the forested landscape and food resources not found elsewhere. Secondary and local roads also affect sexes differently, which could result in demographic and genetic consequences. Models provide a measure of the effect of different roads on bear distribution that can help inform decision-making about development in the forested landscapes of Vermont

    Geo-Statistical Methods for Detecting Elk Parturition Sites from GPS Collar Data

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    There is an increasing awareness of the importance of juvenile survival in ungulate population dynamics, and the accurate prediction of parturition habitat may allow for more effective management. Detecting birth sites in a statistically rigorous way, however, often requires intensive field efforts that may not be possible for all studies. We developed a hierarchical two-stage clustering analysis for identifying elk parturition locations, which can be conducted retrospectively using only GPS location data. We validated our approach using a dataset of 59 adult female elk ( Cervus elaphus) fitted with both a Global Positioning System (GPS) collar (30-minute sampling interval) and vaginal implant transmitter (VIT) For the top parameter set, approximately 80% of estimable parturition sites were within 1 km of their respective VIT location. Roughly 10 % of our predicted birthing locations were over 2 km away from the VIT location, but many of these events could be filtered from the analyses due to their clustering attributes. Designed to minimize Type II errors this filtering also removes a subset of birthing sites that close to VIT locations, and magnitude of this effect varied across parameter sets. Sub-sampling of the GPS dataset from 30 min to 1, 2, 3, and 6 hour intervals resulted in modest reductions in the efficacy of our approach. With the use of GPS collars in ungulate studies on the rise, our approach provides managers with additional information on birth site locations at no additional cost over and above a typical GPS study

    Solar energy harvester for pet GPS collar

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    The power source of wireless technology depends on the device’s battery life and need to be plugged in for recharge purpose. This problem can be solved using energy harvesting system which directly converts solar energy radiated from the sun into electricity. In this project a solar energy harvesting pet collar is developed to harness solar energy and charge the installed battery. The GPS system used a minimum of 2.2V up to 3.6V input voltage. The result obtained shows that the solar panel can give enough power to power up the GPS system as that energy harvester circuit and is able to deliver output up to 4.3V in direct sunlight with an input voltage as low as 3.25V

    Inference of the Activity Timeline of Cattle Foraging on a Mediterranean Woodland Using GPS and Pedometry

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    The advent of the Global Positioning System (GPS) has transformed our ability to track livestock on rangelands. However, GPS data use would be greatly enhanced if we could also infer the activity timeline of an animal. We tested how well animal activity could be inferred from data provided by Lotek GPS collars, alone or in conjunction with IceRobotics IceTag pedometers. The collars provide motion and head position data, as well as location. The pedometers count steps, measure activity levels, and differentiate between standing and lying positions. We gathered synchronized data at 5-min resolution, from GPS collars, pedometers, and human observers, for free-grazing cattle (n = 9) at the Hatal Research Station in northern Israel. Equations for inferring activity during 5-min intervals (n = 1,475), classified as Graze, Rest (or Lie and Stand separately), and Travel were derived by discriminant and partition (classification tree) analysis of data from each device separately and from both together. When activity was classified as Graze, Rest and Travel, the lowest overall misclassification rate (10%) was obtained when data from both devices together were subjected to partition analysis; separate misclassification rates were 8, 12, and 3% for Graze, Rest and Travel, respectively. When Rest was subdivided into Lie and Stand, the lowest overall misclassification rate (10%) was again obtained when data from both devices together were subjected to partition analysis; misclassification rates were 6, 1, 26, and 17% for Graze, Lie, Stand, and Travel, respectively. The primary problem was confusion between Rest (or Stand) and Graze. Overall, the combination of Lotek GPS collars with IceRobotics IceTag pedometers was found superior to either device alone in inferring animal activity
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