Global Positioning System Tags Research Articles

A case report assessing the utility of a low-cost tracking GPS device for monitoring terrestrial mammal movements

BackgroundAccurate data on animal movements can highlight behavioural and ecological issues, such as territorial interactions, barriers to migration patterns, including compromised movement corridors, or avoidance of deteriorating habitats, and disease transmission, thus helping in conservation decision making. This study examines the utility of mOOvement global positioning system (GPS) tags, a low-cost cattle ear tag tracking device to monitor movements of terrestrial mammal populations in South Australia.ResultsStationary tags (n = 40) were used to test horizontal accuracy with a median location error of 33.26 m (IQR = 16.9–59.4), and maximum recorded error of 410 m. The locational accuracy was weakly influenced by the horizontal dilution of precision (HDOP), a measure of satellite availability and geometry, and overhead canopy cover. Numerous tags produced infrequent and inconsistent readings, median of 12 records per day (IQR = 6–12), correlating negatively with the tag’s distance from the centrally located LoRa antenna; however, some tags recorded fewer than one position per day.ConclusionsWe propose that the primary cause of mOOvement tag inadequacy is the use of only the GPS satellite constellation (USA, 1978), which does not provide adequate coverage in either satellite number or geometry in the sky at the − 35° latitude to calculate accurate positions regularly over 24 h, unlike the multiple constellations available in the global navigation satellite system (GNSS). We conclude that GPS tags are unsuitable for studies requiring high locational accuracy or identification of an individual’s social interactions, where the GPS constellation has a limited number of satellites available during prolonged periods. They can, however, be used to provide estimates of home range size or track large scale daily movements of animals in more equatorially located regions.

Global positioning system (GPS) and platform transmitter terminal (PTT) tags reveal fine-scale migratory movements of small birds: A review highlights further opportunities for hypothesis-driven research

Abstract Studying migration is critically important for understanding the full-annual cycle of migrating birds and aids in management and conservation. In recent years, global positioning system (GPS) and platform transmitting terminal (PTT) tags have become miniaturized, revolutionizing migration research by allowing for higher location accuracy and global coverage for smaller species. We reviewed 116 primary research papers from 2006 to 2021 that reported on GPS- or PTT-tagged small birds (<500 g) during migration and assessed research aims, tag efficacy, ecological findings, and future opportunities. Reviewed papers covered 58 unique species (nearly half of which were shorebirds) and 65% of studies tagged birds at breeding grounds. Tags that did not require retrieval had higher success obtaining data, with PTT tags having the greatest success (85% of deployed tags had data). Of studies that reported tag load information, most (70%) reported tag loads ≥3% body mass, which is a potential concern given that 3% is considered the preferable upper limit. Most papers (69%) focused on presenting spatial information such as migratory routes, stopover sites, and habitat use, and only 33% of papers tested explicit hypotheses, demonstrating that we are in the early stages of understanding small bird migration at fine scales. Almost all tag deployments (93%) occurred in the northern hemisphere, most often in the United States (24%), indicating a deficiency in GPS and PTT research on small bird migration from the southern hemisphere. GPS and PTT tags have revealed new biological insights not possible with other technologies by providing fine-scale movement data and global coverage. There are exciting opportunities for researchers to move beyond descriptive spatial studies and explore hypothesis-driven migratory research, into topics such as intraspecific variation, carry-over effects, and climate-driven movements for irruptive species.

Temperature and barometric pressure affect the activity intensity and movement of an endangered thermoconforming lizard

AbstractGlobal warming is expected to affect movement‐related thermoregulation in ectotherms, but the likely effects on thermoconforming lizards, which spend little energy in thermoregulation behavior, are unclear. We used the Guatemalan beaded lizard (Heloderma charlesbogerti) as a model thermoconforming species to investigate the effects of ambient temperature and barometric pressure (a cue for rain in the study area) on activity intensity and the structure of movement paths. We tracked 12 individuals over a total of 148 animal days during the wet season of 2019 using Global Positioning System tags and triaxial accelerometry. We found a clear positive effect of ambient temperature on activity (using vectorial dynamic body acceleration [VeDBA]) and step length of lizard movements. The movement also became more directional (longer step lengths and smaller turning angles) with increasing ambient temperatures. There was a small negative effect of barometric pressure on VeDBA. We propose that our patterns are indicative of internal state changes in the animals, as they move from a state of hunger, eliciting foraging, which is enhanced by lower temperatures and rainfall to a thermally stressed state, which initiates shelter‐seeking. Our findings highlight the sensitivity of this species to temperature change, show that not all thermoconforming lizards are thermal generalists, and indicate that predicted regional increases in temperature and reduction in rainfall are likely to negatively impact this species by reducing the width of their operational thermal window.

Maintaining and Evaluating the Integrity of Digital Evidence in Chain of Custody

The Chain of Custody is an intrinsic part of any inspection. Maintaining and evaluating the integrity of evidence procured from a crime scene is an important part that needs to be done properly by following a certain set of protocols to make the evidence admissible in the court. Keeping track of the evidence right from the moment it was collected from the crime scene till the time it reaches court is also a major task. It is important for the investigator to know how, where and who handles the evidence during analysis at each phase in order to safeguard the integrity of the evidence. Over a period of time, various tools and technologies have been created to handle evidence. Researchers from across the globe have presented various techniques on how evidence should be handled. Many researchers have even incorporated blockchain technology with the chain of custody or life cycle of evidence to make the process stronger. The growth in this domain has been at a rapid pace. This paper presents a method on “Maintaining and Evaluating the Integrity of a Digital Evidence in Chain of Custody” using a global positioning system. The methodology focuses on the use of global positioning system tags or chips which when embedded with the collected evidence enables an investigator to track the evidence throughout its life cycle. The proposed methodology aims to help the investigators to keep track of the evidence throughout its life cycle using very basic tools like FTK Imager and technology like a global positioning system.

Migration ecology of western gray catbirds

BackgroundFor many songbirds in North America, we lack movement details about the full annual cycle, notably outside the breeding season. Understanding how populations are linked spatially between breeding and overwintering periods (migratory connectivity) is crucial to songbird conservation and management. We assessed migratory connectivity for 2 breeding populations of Gray Catbirds (Dumetella carolinensis) west of and within the Rocky Mountains by determining migration routes, stopover sites, and overwintering locations. Additionally, we compared apparent annual survivorship for both populations.MethodsWe deployed 39 archival light-level geolocators and 21 Global Positioning System (GPS) tags on catbirds in the South Okanagan Valley, British Columbia, Canada, and 32 geolocators and 52 GPS tags in the Bitterroot River Valley, Montana, USA. These devices allowed us to determine migration routes, stopover sites, overwintering locations, and migratory connectivity. Migratory connectivity was quantified using Mantel’s correlation. We used mark-recapture of colour banded catbirds in both sites to estimate apparent annual survivorship.ResultsWe retrieved 6 geolocators and 19 GPS tags with usable data. Gray Catbirds from both populations passed through the Rocky Mountains eastward before heading south towards their overwintering locations in northeastern Mexico and Texas. Stopover sites during fall migration occurred primarily in Montana, Kansas, Oklahoma, and Arkansas. Overwintering locations spanned Texas and 5 states in northeastern Mexico. Individual catbirds used up to 4 distinct sites during the overwintering period. Catbirds separated by almost 500 km during the breeding season overlapped during the non-breeding season, suggesting weak migratory connectivity among western populations (Mantel’s correlation = 0.013, P-value = 0.41). Catbird apparent annual survivorship estimates were higher in British Columbia (0.61 ± 0.06 females; 0.64 ± 0.05 males) than in Montana (0.34 ± 0.05 females; 0.43 ± 0.04 males), though the main driver of these differences remain unclear.ConclusionsOur results provide high precision geographic details during the breeding, migration, and overwintering phases of the annual cycle for western Gray Catbirds. Notably, we found that western catbirds followed the Central Flyway as opposed to the Pacific Flyway. We document that catbirds used multiple sites over winter, contrary to the popular belief that this phase of the annual cycle is stationary for most songbirds.

Application of low-power wide-area network GPS to koala monitoring

We evaluated long range antennae and associated solar-powered global positioning system (GPS) ear tags designed for use with domestic cattle, as a novel system for monitoring ranging behaviour of the koala (Phascolarctos cinereus). The mean location error of our GPS tags was 33.9 m (s.e. = 0.46). The tags were relatively light (30 g), reported eight locations per day when attached to koala radio-collars and had an operating life that exceeded our study period (8 months). Deployed as a stand-alone, solar powered, remote system, this technology can provide a viable option for wildlife tracking projects.

Daily Movements, Space Use, and Habitat Selection of GPS‐tagged Northern Bobwhite in Texas

ABSTRACTDetailed information on movements, space use, and habitat selection patterns by northern bobwhite (Colinus virginianus; hereafter, bobwhite) is important for understanding population dynamics, gene flow, disease spread, and development of habitat management activities. Advances in Global Positioning System (GPS) technology has allowed researchers to collect spatial and temporal location data with increasing accuracy, which in turn has shifted the resolution at which habitat evaluations and management focus can occur. Only recently have GPS tags been deployable for small ground‐nesting birds. We conducted a preliminary examination of the spatial ecology of 74 bobwhites equipped with GPS tags during breeding and covey season on 3 private properties in north‐central Texas, USA, during 2015–2017. Specifically, we derived daily estimates of core area and range size using dynamic Brownian bridge movement models, daily distance traveled, and distance between consecutive roost sites. Bobwhites tended to move more during breeding than covey season. Consecutive roost sites were, on average, approximately 130 m apart. Daily core area and home range size of bobwhites across the calendar year were 1.99 ± 0.13 and 6.29 ± 0.85 ha, respectively. During the breeding season, bobwhites avoided hardwood communities and showed no selection or avoidance of shrub, grass, and herbaceous communities. During covey season, bobwhites selected for herbaceous, grass, and hardwood communities, and neither selected nor avoided shrub communities. Global Positioning System data on a variety of species has become the primary information used for habitat and conservation management decisions, therefore, future research on bobwhite will include the application of GPS, which our results show can increase the temporal resolution of information and be used for habitat conservation and restoration actions. © 2020 The Wildlife Society.

Short-term tracking tag attachment disrupts chick provisioning by Atlantic Puffins Fratercula arctica and Razorbills Alca torda

ABSTRACTCapsuleAtlantic Puffins Fratercula arctica and Razorbills Alca torda alter their chick provisioning behaviour when equipped with tracking loggers.AimsTo test whether feeding data from global positioning system (GPS) tags in a companion project represented normal behaviour, we examined the effect of externally mounted GPS loggers on parental effort of Atlantic Puffins and Razorbills through chick measurements and video recordings to determine individual responses to tagging.MethodsWe compared chick growth, nest attendance and provisioning between breeding pairs with and without tagged birds (nest-level), as well as between tagged and untagged mates (mate-level) with the aim of revealing responses of untagged partners to the tagging of their mate.ResultsWe found all measures of parental effort compared at the nest-level to be similar between nests with one tagged adult and nests without tagged birds. However, video recordings revealed differences in individual behaviour in both species, in which untagged partners spent more time provisioning the chick and also delivered significantly more food to chicks than their tagged partners, though partners shared nest attendance.ConclusionBehaviours revealed through video recordings showed that the GPS tags introduced bias against detecting where adults forage for their chicks. Future tracking studies should consider measures of tag effect at both the mate- and nest-level as well as the potential bias in the movement data when making biological inferences.

Seasonal and circadian biases in bird tracking with solar GPS-tags.

Global Positioning System (GPS) tags are nowadays widely used in wildlife tracking. This geolocation technique can suffer from fix loss biases due to poor satellite GPS geometry, that result in tracking data gaps leading to wrong research conclusions. In addition, new solar-powered GPS tags deployed on birds can suffer from a new “battery drain bias” currently ignored in movement ecology analyses. We use a GPS tracking dataset of bearded vultures (Gypaetus barbatus), tracked for several years with solar GPS tags, to evaluate the causes and triggers of fix and data retrieval loss biases. We compare two models of solar GPS tags using different data retrieval systems (Argos vs GSM-GPRS), and programmed with different duty cycles. Neither of the models was able to accomplish the duty cycle programed initially. Fix and data retrieval loss rates were always greater than expected, and showed non-random gaps in GPS locations. Number of fixes per month of tracking was a bad criterion to identify tags with smaller biases. Fix-loss rates were four times higher due to battery drain than due to poor GPS satellite geometry. Both tag models were biased due to the uneven solar energy available for the recharge of the tag throughout the annual cycle, resulting in greater fix-loss rates in winter compared to summer. In addition, we suggest that the bias found along the diurnal cycle is linked to a complex three-factor interaction of bird flight behavior, topography and fix interval. More fixes were lost when vultures were perching compared to flying, in rugged versus flat topography. But long fix-intervals caused greater loss of fixes in dynamic (flying) versus static situations (perching). To conclude, we emphasize the importance of evaluating fix-loss bias in current tracking projects, and deploying GPS tags that allow remote duty cycle updates so that the most appropriate fix and data retrieval intervals can be selected.

First Direct Evidence of Long-distance Seasonal Movements and Hibernation in a Migratory Bat.

Understanding of migration in small bats has been constrained by limitations of techniques that were labor-intensive, provided coarse levels of resolution, or were limited to population-level inferences. Knowledge of movements and behaviors of individual bats have been unknowable because of limitations in size of tracking devices and methods to attach them for long periods. We used sutures to attach miniature global positioning system (GPS) tags and data loggers that recorded light levels, activity, and temperature to male hoary bats (Lasiurus cinereus). Results from recovered GPS tags illustrated profound differences among movement patterns by individuals, including one that completed a >1000 km round-trip journey during October 2014. Data loggers allowed us to record sub-hourly patterns of activity and torpor use, in one case over a period of 224 days that spanned an entire winter. In this latter bat, we documented 5 torpor bouts that lasted ≥16 days and a flightless period that lasted 40 nights. These first uses of miniature tags on small bats allowed us to discover that male hoary bats can make multi-directional movements during the migratory season and sometimes hibernate for an entire winter.

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.

Research challenges and opportunities in mapping social media and Big Data

Social media and Big Data have transformed our world into interconnected cyberspace and realspace. Cartographers can now trace, monitor, and map the spread of social movements, disease outbreaks, nature hazards, and popular events by digitally collecting social media and Big Data with locational contents, such as global positioning system tags and user location profiles. The dynamic characteristics of social media and Big Data provide a great research opportunity for cartographers to map and analyze human behaviors, communications, and movements. However, there are many challenges and pitfalls in cartographic research associated with spatiotemporal analysis of social media contents and Big Data. This short paper will address important research challenges and major opportunities for cartographers to process and visualize Big Data and social media.

Using sutures to attach miniature tracking tags to small bats for multimonth movement and behavioral studies.

Determining the detailed movements of individual animals often requires them to carry tracking devices, but tracking broad-scale movement of small bats (<30 g) has been limited by transmitter technology and long-term attachment methods. This limitation inhibits our understanding of bat dispersal and migration, particularly in the context of emerging conservation issues such as fatalities at wind turbines and diseases. We tested a novel method of attaching lightweight global positioning system (GPS) tags and geolocating data loggers to small bats. We used monofilament, synthetic, absorbable sutures to secure GPS tags and data loggers to the skin of anesthetized big brown bats (Eptesicus fuscus) in Colorado and hoary bats (Lasiurus cinereus) in California. GPS tags and data loggers were sutured to 17 bats in this study. Three tagged bats were recaptured 7 months after initial deployment, with tags still attached; none of these bats showed ill effects from the tag. No severe injuries were apparent upon recapture of 6 additional bats that carried tags up to 26 days after attachment; however, one of the bats exhibited skin chafing. Use of absorbable sutures to affix small tracking devices seems to be a safe, effective method for studying movements of bats over multiple months, although additional testing is warranted. This new attachment method has the potential to quickly advance our understanding of small bats, particularly as more sophisticated miniature tracking devices (e.g., satellite tags) become available.

Miniaturized GPS Tags Identify Non-breeding Territories of a Small Breeding Migratory Songbird.

For the first time, we use a small archival global positioning system (GPS) tag to identify and characterize non-breeding territories, quantify migratory connectivity, and identify population boundaries of Ovenbirds (Seiurus aurocapilla), a small migratory songbird, captured at two widely separated breeding locations. We recovered 15 (31%) GPS tags with data and located the non-breeding territories of breeding Ovenbirds from Maryland and New Hampshire, USA (0.50 ± 0.15 ha, mean ± SE). All non-breeding territories had similar environmental attributes despite being distributed across parts of Florida, Cuba and Hispaniola. New Hampshire and Maryland breeding populations had non-overlapping non-breeding population boundaries that encompassed 114,803 and 169,233 km2, respectively. Archival GPS tags provided unprecedented pinpoint locations and associated environmental information of tropical non-breeding territories. This technology is an important step forward in understanding seasonal interactions and ultimately population dynamics of populations throughout the annual cycle.

Daytime Habitat Selection by Resident Golden Eagles (Aquila chrysaetos) in Southern Idaho, U.S.A

Energy and other anthropogenic development are increasing throughout the range of Golden Eagles (Aquila chrysaetos) in western North America, and both private and government agencies have expressed concern about indirect and direct effects on Golden Eagles. To facilitate sustainable development and reduce risk to Golden Eagles, the U.S. Fish and Wildlife Service has established guidelines to assist developers in project planning and siting. A major component of environmental impact assessment is documenting Golden Eagle spatial use near a project site before development. Unbiased estimates of habitat selection (spatial use) in and near a proposed project area are possible with location data collected by Global Positioning System (GPS) transmitters attached to a sample of Golden Eagles in the area. During spring 2011, we identified occupied Golden Eagle territories within a study area in southern Idaho, and deployed four GPS and Argos tags on resident adult Golden Eagles. We developed seasonal resource selection functions (RSFs) for each monitored Golden Eagle, and estimated seasonal daytime habitat selection by the average Golden Eagle by averaging predictions from four RSFs. The final RSFs estimated that relative probability of selection by Golden Eagles was highest closer to nests and over moderately rugged terrain. Other predictor variables such as brightness (a measure of non-vegetated habitats) and slope were also seasonally important. Model validation indicated the models reliably predicted Golden Eagle use within the study area. This is the first study estimating Golden Eagle habitat selection based on a combination of GPS and nest locations. The process we developed may be used to improve our understanding of Golden Eagle habitat selection and to provide valuable information to help minimize risk to Golden Eagles from different land management practices.La obtención de energía y otras actividades de desarrollo antrópico se están extendiendo a lo largo de la distribución de Aquila chrysaetos en el oeste de América del Norte, y tanto las agencias privadas como las gubernamentales han expresado su preocupación acerca de los efectos directos e indirectos sobre esta especie. Para facilitar el desarrollo sostenible y reducir el riesgo para A. chrysaetos, el Servicio de Pesca y Vida Silvestre de Estados Unidos ha establecido lineamientos para ayudar a los promotores en la planificación y emplazamiento de proyectos. Un componente principal de la evaluación del impacto ambiental es documentar el uso del espacio que realiza A. chrysaetos en las inmediaciones de un lugar donde se emplazará un proyecto, antes de su desarrollo. Para ello, es posible obtener estimaciones no sesgadas de selección de hábitat (uso espacial) dentro o cerca de un área propuesta para un proyecto, con datos de posicionamiento obtenidos mediante transmisores GPS (Sistema de Posicionamiento Global) colocados a una muestra de A. chrysaetos en el área. Durante la primavera de 2011 identificamos territorios ocupados por individuos de A. chrysaetos dentro de un área de estudio en el sur de Idaho y colocamos cuatro transmisores de tipo GPS y Argos en individuos adultos residentes. Desarrollamos funciones de selección de recursos (FSRs) estacionales para cada individuo monitorizado y estimamos la selección de hábitat diurno estacional de un individuo tipo de A. chrysaetos promediando las predicciones de las cuatro FSRs. Las FSRs finales estimaron que la probabilidad relativa de selección de hábitat por parte de A. chrysaetos fue mayor cerca de los nidos y en terrenos moderadamente irregulares. Otras variables predictivas tales como el brillo (una medida de hábitats sin vegetación) y la pendiente también fueron importantes estacionalmente. La validación del modelo indicó que los modelos predijeron de manera confiable el uso del espacio por parte de A. chrysaetos en el área de estudio. Este es el primer estudio que estima el uso de hábitat de A. chrysaetos basado en

Implementation of VANET-based Warning Generation System using Cellular Networks, GPS, and Passive RFID Tags

Vehicular communication systems are a key part of an intelligent transportation system, while vehicle safety communication is a major target of vehicular communication. Other features that augment vehicular ad hoc networks are enhanced driving experience, including but not limited to, active navigation and weather information, real-time traffic information and a plethora of other autonomous and automated systems. However, our focus will be warning generation systems, which can help reduce fatalities if deployed in an efficient and fail-safe manner on motorways and highways. This paper describes a collective information system for collection and delivery of traffic information aimed at supporting fast, efficient and secure travel of people and transport of goods. Based on that information, authorities are able to assess vehicles’ sudden motion and movement changes and can generate warning/alert messages (for emergency/police vehicles) for post-accident scenarios. In this paper, the use of a radio frequency identification (RFID) system for vehicular communication has been proposed and an extended RFID system and infrastructure for vehicle safety communication through emergency phone towers (EPTs) and cell phones is suggested. In order to communicate, vehicles may be equipped with a cellular phone, RFID, and/or a global positioning system (GPS), whereas RFID readers may be mounted on EPTs, which are already installed on motorways. It also provides a demonstration on flow of information within the system; the simulation results are also included.

Accelerometer‐informed GPS telemetry: Reducing the trade‐off between resolution and longevity

AbstractTracking animal movement using Global Positioning System (GPS) technology is an increasingly popular method for studying animal ecology, behavior, and conservation. To date, most GPS location schedules have been set at regular intervals. If intervals are too long, they undersample the details of movement paths, and if too short, they oversample resting sites and deplete the unit's battery without providing new information. We address this problem by creating a dynamic GPS schedule that is linked to the activity level of the animal via an accelerometer onboard the tracking tag. We deployed traditional and accelerometer‐informed GPS tags on northern tamanduas anteater (Tamandua mexicana) in tropical forest in the Republic of Panama (2009–2010), and on fisher (Martes pennanti) in temperate forest in New York, USA (2009–2011). These species are medium‐sized forest‐dwellers that frequently use tree cavities, ground burrows, and thick vegetation for resting and foraging, all traits that make them particularly challenging for GPS tracking. The accelerometer‐informed tags performed better than the traditional GPS tags: they attempted 73.6% more locations per day, achieved 61.7% higher location success rates, spent 28.2% less time searching for satellites, made 67.4% fewer redundant location attempts in places where animals were inactive, and ultimately provided more data for a given battery size. The resulting tracks of animal movement had high temporal resolution, revealing aspects of their behavior and ecology that would have been missed by traditional tags, especially for the fast‐moving fisher. By dynamically linking the location schedule to animal movement rate, accelerometer‐informed GPS tags reduce the trade‐off between collecting detailed movement data and recording movement data for a longer period of time. © 2012 The Wildlife Society.