GPS Telemetry Research Articles

Examining Internal and External Physical Workloads Between Training and Competitive Matches Within Collegiate Division I Men's Soccer.

Anderson, T, Adams, WM, Martin, KJ, and Wideman, L. Examining internal and external physical workloads between training and competitive matches within collegiate Division I men's soccer. J Strength Cond Res 35(12): 3440-3447, 2021-A direct analysis comparing differences in the demands of competition relative to in-season training in Division I collegiate soccer players has yet to be reported. Thus, the primary purpose of this study was to compare the absolute and relative internal and external workloads measured during training with competitive matches. Twenty-six male college soccer players were monitored over 2 consecutive seasons using a GPS and heart rate (HR) telemetry system. Differences between outdoor training sessions and competitive matches were analyzed for internal and external absolute and relative training workloads. Differences in training workloads between the 3 days before a match were also analyzed. Absolute time in HR zone 4 (80-89% of HRmax) and 5 (90-100% of HRmax); accelerations in zone 1 (0.50-0.99 m·s-2), zone 2 (1.00-1.99 m·s-2), and zone 3 (2.00-2.99 m·s-2); all negative acceleration zones; training load; and estimated energy expenditure were greater in competition than training (p < 0.05). By contrast, when comparing training and competition values using metrics relative to session duration, relative workload in trainings were greater than competition for HR zone 1 (50-59% of HRmax), zone 2 (60-69% of HRmax), zone 3 (70-79% of HRmax), and zone 4 (80-89% of HRmax) and all acceleration and negative acceleration zones. In addition, absolute training workloads were generally greatest 3 days prior (p < 0.01), but not different 2 days before the competitive match. Absolute physical workloads of competition are significantly greater than those achieved during training; however, these differences and impact on the physical condition of players are mitigated by the greater relative workloads achieved during training. These results provide meaningful metrics that may lead to insights into proper conditioning and in-season workload management for Division I collegiate soccer programs.

Drivers of Flight Performance of California Condors (Gymnogyps californianus)

ABSTRACT Flight behavior of soaring birds depends on a complex array of physiological, social, demographic, and environmental factors. California Condors (Gymnogyps californianus) rely on thermal and orographic updrafts to subsidize extended bouts of soaring flight, and their soaring flight performance is expected to vary in response to environmental variation and, potentially, with experience. We collected 6298 flight tracks described by high-frequency GPS telemetry data from five birds ranging in age from 1 to 19 yr old and followed over 32 d in summer 2016. Using these data, we tested the hypothesis that climb rate, an indicator of flight performance, would be related to the topographic and meteorological variables the bird experienced, and also to its age. Climb rate was greater when condors were flying in faster winds and during environmental conditions that were conducive to updraft development. However, we found no effect of age on climb rate. Although many of these relationships were expected based on flight theory, the lack of an effect of age was unexpected. Our work expands understanding of the relationship condors have with the environment, and it also suggests the potential for as-yet unexplored complexity to this relationship. As such, this study provides insight into avian flight behavior and, because flight performance influences bird behavior and exposure to anthropogenic risk, it has potential consequences for development of conservation management plans.

Seasonal and Age-Related Variation in Daily Travel Distances of California Condors

Despite a dramatic recovery from the brink of extinction, California Condors (Gymnogyps californianus) still face significant anthropogenic threats. Although condor movement patterns across large temporal scales are understood, less is known about their movements on a fine temporal scale. We used a trajectory-based analysis of GPS telemetry data gathered from condors during 2013 to 2018 to investigate the relationship between the distances condors travel in a day, demographic characteristics (e.g., age and sex), and time of year. Most (>71.4%) daily travel distances by condors were <100 km, and, on average, condors traveled 70.1 ± 60.9 km/d (x̄ ± SD). On two occasions one condor traveled >400 km in a single day (477 km one day and 415 km the following day). The tendency for condors to travel long distances increased with age, and condors traveled longer distances during the summer and when nesting. Traveling such long distances likely exposes birds to threats across a greater variety of landscapes than would be expected for birds that moved shorter distances. Given anticipated condor range expansion and population increase, this work highlights the importance of coordinating condor conservation across the broad spatial scales at which they move.

Forecasting habitat and connectivity for pronghorn across the Great Basin ecoregion

AbstractAimsIn the sagebrush ecosystems of the western United States, identifying and enhancing habitat for large ungulates has become an increased priority for many management agencies, as indicated by Department of Interior Secretarial Order 3362. Estimating and understanding current and future habitat suitability and connectivity is important for successful long‐term management of these species.LocationGreat Basin ecoregion, western USA.MethodsWe focussed on pronghorn (Antilocapra americana) in the Great Basin ecoregion and used a variety of data sources (GPS telemetry, aerial surveys, observation locations) to develop multi‐scale ensemble habitat suitability models for the current and two future time steps (years 2050 and 2070). We also developed dynamic resistant kernels to model pronghorn connectivity. We combined the habitat suitability and connectivity outputs to derive and quantify changes in pronghorn habitat networks through time as well as identify areas that are resilient to climate and land use change.ResultsWe observed a 33.4% decline in highly suitable pronghorn habitat by 2070, assuming a high carbon emission scenario. Patches of suitable habitat reduced in number and size, whilst the distance amongst patches increased, indicating elevated importance of connectivity for pronghorn in the future. Future connectivity decreased to a greater degree than habitat suitability (47.2%–80.0%, depending on the pronghorn movement threshold used). We also found highly suitable habitat (70%) to be more resilient to climate change than areas of connectivity (10%–15%).Main conclusionsOur results show a loss of high‐quality pronghorn habitat and areas of connectivity with projected climate change. Connectivity was more sensitive than habitat, indicating connectivity may become a limiting factor for pronghorn populations in the Great Basin. These results can help managers prioritize resource investments and conservation efforts in areas most likely to be successful towards long‐term pronghorn conservation.

Female and male Eurasian lynx have distinct spatial tactics at different life-history stages in a high-density population.

Knowledge regarding the spatial behavior of the Eurasian lynx is mainly inferred from populations in Europe. We used GPS telemetry to record the spatial behavior of nine individuals in northwestern Anatolia obtaining eleven home ranges (HRs). Analyses revealed the smallest mean HR sizes (nHR ♀ = 4) at 57 km2 (95% kernel utilization distribution, KUD) and 56 km2 (95% minimum convex polygon, MCP), ever reported for adult female Eurasian lynx. Adult males either occupied small permanent territories (nHR♂.T = 2), with a mean of 176 km2 (95% KUD) and 150 km2 (95% MCP), or were residents without territories (floaters, nHR♂. F = 2) roaming across large, stable HRs with a mean size of 2,419 km2 (95% KUD) and 1,888 km2 (95% MCP), comparable to HR sizes of Scandinavian lynx populations. Three disperser subadult males did not hold stable HRs (mean 95% KUD = 203 km2, mean 95% MCP = 272 km2). At 4.9 individuals per 100 km2, population density was one of the highest recorded, suggesting that the presence of adult male floaters was a consequence of a landscape fully occupied by territorials and revealing a flexibility of spatial behavior of Eurasian lynx not previously recognized. Such a high population density, small HRs, and behavioral flexibility may have been aided by the legal protection from and apparent low levels of poaching of this population. The observed spatial tactics are unlikely to be seen in most of the previously studied Eurasian lynx populations, as they either suffer medium to high levels of human‐caused mortality or were unlikely to be at carrying capacity. For effective and appropriate conservation planning, data from felid populations in a reasonably natural state such as ours, where space, density, prey, and pathogens are likely to be the key drivers of spatial dynamics, are therefore essential.

Spatial and temporal responses of swamp wallabies to roads in a human-modified landscape

Roads can have significant impacts on wildlife populations by impeding movement, restricting access to resources and causing wildlife–vehicle collisions. In particular, wildlife–vehicle collisions represent a substantial conservation and social problem, and although mitigation measures are available, an increased understanding of the temporal and spatial patterns of animal movement around roads will enhance their effectiveness. We analysed GPS telemetry data from 47 swamp wallabies Wallabia bicolor on Phillip Island, south-east Australia, within patches of native vegetation dissected by roads. Our aims were to determine if (a) road crossing frequency was influenced by time period (day, night) or sex, (b) wallabies avoided roads, and if avoidance was influenced by time period or sex and (c) road crossing locations were associated with dense vegetation, and other habitat characteristics. We found that males crossed roads more often at night than during the day while females showed the opposite pattern. Further, wallabies avoided roads, with some evidence that avoidance increased at night (p = 0.07). The chance of a wallaby crossing roads with high speed limits (80–100 km h-1) increased with vegetation density during the day but not at night. In contrast, vegetation density had no influence on crossing locations along roads with lower (50–70 km h-1) speed limits during the day or night. Both vegetation density and vehicle speed may influence wallaby–vehicle collisions and suggest management strategies targeting these factors. Partial fencing guiding wallabies towards safer crossing locations, combined with other measures such as reduced speed limits and signage, could reduce collisions between vehicles and swamp wallabies on Phillip Island.

Drone Design for Monitoring Andes Mountains

Introduction Volcanic eruptions are a serious threat to the environment. The volcanic ash can contaminate water, vegetation, livestock and people. The Andes or Andean Mountains are the longest continental mountain range in the world, with a length of 8500 km. and presents different volcanoes [1]. In our work group the gas emissions of the Peteroa volcano are analyzed. In order to assess more accurately the state of a volcanic zone, spatially distributed measurements are required. Consequently, it is necessary to have an unmanned aerial vehicle to obtain several measurement points. An Electronic Nose (eNose) and a quadcopter drone equipped with gas sensors for CO2, temperature and humidity were developed [2][3]. The Dron eNose system provides a versatile technology for autonomous monitoring of diverse environments. The use of this device minimizes the risks of exposure to dangerous compounds for people and allows exploring inaccessible areas. The advantage of this system, over drones sold in the market (provided with proprietary software), lies in the possibility of adding accessories, which gives to it more adaptability. In this work, the complete structure of the quadcopter was manufactured using a 3D printer. To obtain a robust frame, parts were printed with filaments composed of different materials. Motors and propellers were selected according to the drone load capacity, the sensors, the stability control and the teletransmission system. The system is very versatile and different gas sensors can be added such as for detect SO2 and H2S. The flight can be controlled manually by remote control, or autonomously by a programmed flight plan. Method The implemented methodology was aimed at: 1) developing a drone (mobile robot) with an eNose system carrying capacity; 2) the testing of analytical capabilities of the assembled system by conducting studies in semi-field conditions (small spaces under controlled conditions). Once these objectives have been met, an area or region of interest may be explored to sample pollutants and to obtain their distribution map. Results in different project stages contribute to the development of new technologies relevant to environmental chemistryDrone structure parts were manufactured using a 3D printer. Drone arms rigidity tests were performed. The weights of each arm must be constant, the tubular arms oscillate less than the rectangular ones, so the former was chosen. This improved the structural rigidity of the drone. The electronic controller had to compensate for vibrations, therefore, it was essential to have more rigidity. The selected design allows to be printed without support material, and can accommodate a 3 cells 6000 mAh or 4 cells 4200 mAh LiPo battery. In addition, it is possible to put a camera and / or sensors in their compartments. Four Readytosky model 2212 of 920kv motors and suitable propellers were selected. A Pixhawk PX4 Autopilot PIX 2.4.8 32-bit flight controller was chosen because of its benefits: it has a real-time operating system (RTOS), multiple communication interfaces, a backup power system, manual and automatic flight modes and the ability to record flight data on an SD card. The chosen kit also includes a GPS module and telemetry. The connection with the drone is done through a Radiolink AT9S 2.4G 9CH transmitter.The gas detection system (eNose) to be mounted on the drone consist of a plate containing the gas sensors, the electronics for sensors measurements and an Arduino Nano 3.0 microcontroller. It processes the obtained signals. Data is analyzed on a PC with user friendly pattern recognition software which has a GUI that allows to pick between the following algorithms: PCA, Fisher and linear classifiers [4][5].The sensor array consists of 6 Microsens MOS type gas sensors. Part of this arrangement consisted of three MSGS-3000i sensors. The MSGS-3000i Gas Sensor detects carbon monoxide, hydrocarbons, ethanol and volatile organic compounds emissions. The remaining part of the arrangement consisted of three MSGS-3007i sensors. The MSGS-3007i detects NO2 in 0.05 to 5 ppm range. Due to the integrated sockets that the eNose possess, sensors could be easily changed to detect different compounds. The assembled drone is shown in Fig. 1. Results and Conclusions The implementation of a drone eNose system would be one of the first in Argentina. It has the advantage of being a flexible system. This project was carried out with the objective of studying the negative environmental impacts arisen from volcanic eruptions. The technological innovations of this project could be applied to other fields of monitoring. For example, control of high risk of toxicity areas due to the emission of gaseous pollutants, inaccessible for humans.

Stability of space use in Svalbard coastal female polar bears: intra-individual variability and influence of kinship

Philopatry influences animal distribution and can lead to a kinship-based spatial structure, where proximity and relatedness are tightly linked. In the Barents Sea region, polar bears (Ursus maritimus) of the coastal ecotype remain year-round within the Svalbard archipelago. This coastal strategy is thought to be stable across years; however, little is known about the intra-individual variability in site fidelity or the influence of kinship on space use. Using high-resolution GPS telemetry, we looked at multi-year philopatry among 17 coastal female polar bears over eight years (2011–19) and investigated whether it is linked to the females’ degree of kinship. Individuals showed a stable space use in both consecutive and non-consecutive years. Yearly individual home ranges (HRs) overlapped, on average, by 44% (range: 9–96%), and their centroids were, on average, 15 km (range: 2–63 km) apart. The space use of related females revealed a year-round strong female kin structure. Annual HRs of related females overlapped, on average, by 24% (range: 0–66%), and their centroids were, on average, 18 km (range: 2–52 km) apart. In contrast, non-related females had much larger distances between centroids (average: 160 km, range: 59–283 km). Additionally, females showed a great site fidelity in all seasons: individual seasonal HR centroids were, on average, less than 30 km (range: 1.8–172 km) apart. Bears in this region seem to exhibit a stronger site fidelity than those reported from other parts of the species range. These findings also highlight the importance of maternal learning in space use.

Large area used by squirrel gliders in an urban area, uncovered using GPS telemetry.

The squirrel glider (Petaurus norfolcensis) is a threatened, gliding marsupial that persists in fragmented landscapes despite its restricted capacity to cross large gaps. As measures to maintain and/or restore suitable habitat depend on knowledge about the species' ecological requirements, we investigated the area used by squirrel gliders in an urban area near Newcastle, Australia. Using GPS telemetry data and the autocorrelated kernel density estimator, we estimated area used to average 10.8 ha and varied from 4.6 to 15 ha, which is equal to or greater than found in previous studies that spanned longer time periods. This has implications when identifying the minimum patch size necessary for ensuring the long‐term conservation of a squirrel glider population.

Testing the precision and sensitivity of density estimates obtained with a camera-trap method revealed limitations and opportunities.

The use of camera traps in ecology helps affordably address questions about the distribution and density of cryptic and mobile species. The random encounter model (REM) is a camera‐trap method that has been developed to estimate population densities using unmarked individuals. However, few studies have evaluated its reliability in the field, especially considering that this method relies on parameters obtained from collared animals (i.e., average speed, in km/h), which can be difficult to acquire at low cost and effort. Our objectives were to (1) assess the reliability of this camera‐trap method and (2) evaluate the influence of parameters coming from different populations on density estimates. We estimated a reference density of black bears (Ursus americanus) in Forillon National Park (Québec, Canada) using a spatial capture–recapture estimator based on hair‐snag stations. We calculated average speed using telemetry data acquired from four different bear populations located outside our study area and estimated densities using the REM. The reference density, determined with a Bayesian spatial capture–recapture model, was 2.87 individuals/10km2 [95% CI: 2.41–3.45], which was slightly lower (although not significatively different) than the different densities estimated using REM (ranging from 4.06–5.38 bears/10km2 depending on the average speed value used). Average speed values obtained from different populations had minor impacts on REM estimates when the difference in average speed between populations was low. Bias in speed values for slow‐moving species had more influence on REM density estimates than for fast‐moving species. We pointed out that a potential overestimation of density occurs when average speed is underestimated, that is, using GPS telemetry locations with large fix‐rate intervals. Our study suggests that REM could be an affordable alternative to conventional spatial capture–recapture, but highlights the need for further research to control for potential bias associated with speed values determined using GPS telemetry data.

Effects of human-altered landscapes on a reintroduced ungulate: Patterns of habitat selection at the rangeland-wildland interface

Successful species reintroductions require land managers to balance the goal of viable wildlife populations with potential risks to human enterprise. Such risks are particularly acute at the wildland-agriculture interface, where native and domestic species are likely to come into contact. In a national park in northern California, we combined insights from three lines of evidence – long-term visual surveys, short-term GPS telemetry, and satellite remote sensing-based animal detections – to characterize spatial overlap between reintroduced tule elk (Cervus canadensis nannodes) and domestic cattle and to estimate the importance of multiple environmental features as predictors of habitat selection by elk. Our results indicate that, at large spatial scales (i.e., home-range level), cattle were the primary driver of habitat selection, with the occurrence of elk being negatively associated with cattle across all seasons. In addition, elk consistently selected for grasslands on gentle, south-facing slopes that occurred at high elevation and close to ponds. NDVI was a seasonally important, positive predictor of habitat selection, with a marked reversal when this resource was concentrated inside of fenced cow pastures during the dry summer months. By contrast, a novel analysis of satellite-derived animal locations yielded no evidence of avoidance of cattle by elk (within pasture areas commonly used by elk), indicating that this population has acclimated to the presence of cattle through spatial partitioning of resources. Thus, this once-imperiled native ungulate exhibits patterns of habitat selection that reduce the potential for grazing conflicts with cattle, even in cases where access to forage is limited.

Source-sink dynamics promote wolf persistence in human-modified landscapes: Insights from long-term monitoring

Long-term monitoring studies assessing wolf population dynamics are scarce, particularly in human-dominated landscapes of southern Europe. In this work, we estimate wolf demographic parameters in northwest Portugal based on a multi-methodological approach over 20 years split into two periods (period A: 1996–2005; period B: 2007–2016). Period B takes advantage of methodological upgrades in wolf surveys, as GPS telemetry and the use of genetic noninvasive samples, to report dispersal events and identify core and sink packs. The average annual population size was 27.0 ± 2.1 (SE; range 13–43) individuals, with 2 to 6 annual packs and an average density of 1.7 ± 0.1 wolves/100km2. The population showed a growth rate of 4.2 ± 7.6%, with a decreasing trend (period A, −8 ± 9%) followed by a recovery (period B, 16 ± 11%), mainly due to local extinction and reestablishment of sink packs. The average pack size was 6.2 ± 0.3 individuals, with a maximum of 16 individuals, the highest reported value for Iberian wolves. During period B, the percentage of dispersers detected in this population was 11% and the average dispersal distance was 24.8 ± 1.2 km. Core packs showed higher group persistence, breeding success, and average pack sizes compared with sink packs. Results suggest a source-sink dynamics in this population, with few core packs promoting the maintenance and recovery of sink packs through a stepping-stone process. Our findings provide a comprehensive overview of wolf population dynamics in human-dominated landscapes and reinforce that wolf management and conservation planning should take into consideration population trends based on long-term studies, and spatial dynamics of demographic traits across packs.

Factors affecting the home range of Dinaric-Pindos brown bears

Abstract Studying how animals interact with their environment is fundamental to informing conservation and management efforts, especially when examining large, wide-ranging carnivores in human-dominated landscapes. We hypothesized that the home ranges of bears are configured to exploit supplemental food (corn) and avoid people. In 2004–2016, we tracked 10 brown bears from the Dinaric-Pindos population using GPS telemetry, then used Brownian bridge movement models to estimate their home ranges. We related seasonal home range size to circadian period and density of supplemental feeding sites using generalized linear mixed-effect models. We also used ecological-niche factor analysis to study habitat composition within home range core areas in study areas characterized by different levels of human encroachment. We found that home range size was inversely related to density of supplemental feeding sites, and bears had larger home ranges at night (x̅ = 103.3 ± 72.8 km2) than during the day (x̅ = 62.3 ± 16.6 km2). Our results also revealed that bears living in more human-influenced areas concentrated their use far from human settlements and agricultural lands but stayed close to supplemental feeding sites. Our data suggest that bears alter their space-use patterns at the home range level in response to anthropogenic land use and food availability.

Extreme home range sizes among Eurasian lynx at the northern edge of their biogeographic range.

Eurasian lynx (Lynx lynx) have a wide distribution across Eurasia. The northern edge of this distribution is in Norway, where they reach up to 72 degrees north. We conducted a study of lynx space use in this region from 2007 to 2013 using GPS telemetry. The home range sizes averaged 2,606 (± 438 SE) km2 for males (n = 9 ranges) and 1,456 (± 179 SE) km2 for females (n = 24 ranges). These are the largest home ranges reported for any large felid, and indeed are only matched by polar bears, arctic living wolves, and grizzly bears among all the Carnivora. The habitat occupied was almost entirely treeless alpine tundra, with home ranges only containing from 20% to 25% of forest. These data have clear implications for the spatial planning of lynx management in the far north as the current management zones are located in unsuitable habitats and are not large enough to encompass individual lynx movements.

Spatial patterns of weed dispersal by wintering gulls within and beyond an agricultural landscape

Abstract Non‐frugivorous waterbirds disperse a wide variety of plants by endozoochory, providing longer‐dispersal distances than other mechanisms. Many waterbirds visit both agricultural and natural landscapes during their daily movements, but potential bird‐mediated dispersal of weed plants within and from agricultural landscapes to other habitats is commonly overlooked. Gulls (Laridae) are expanding in numbers and increasingly exploiting anthropogenic habitats worldwide, with possible growing implications for the spread of weeds. Yet, to date, there are no studies on the spatial distribution of weed dispersal by waterbirds. We developed a plant dispersal model based on movements of 19 Larus fuscus using ricefields, via GPS telemetry. We combined daily movements with two curves estimating the retention times of plant seeds in their guts: (a) an experimental curve based on retention time in captivity for four weeds with dry fruits known to be dispersed by gulls: Juncus bufonius, Cyperus difformis, Polypogon monspeliensis and the alien Amaranthus retroflexus; (b) a theoretical curve based on the interspecific scaling relationship between body mass and mean retention time. Median dispersal distances of weed plant seeds by gulls ranged between 690 and 940 m, but maximum distances exceeded 150 km. The theoretical retention time model showed higher median dispersal distances than the experimental retention time model. Spatial patterns of weed deposition were very similar between retention time methods, and most strongly depended on gull movements. Variation between individual gulls had little influence on seed shadows. About 92% of all seeds (&gt;10,000 intact seeds per day) were dispersed within the ricefield area of 370 km2. The remaining 8% of seeds were deposited beyond ricefields into other habitats, 42% of which reached moist environments (other irrigated agriculture, rivers and natural wetlands) presumably suitable for weed establishment. Synthesis. Gulls can disperse weed plants over long distances across a mosaic of habitats. This implies exchange of weed plant species between human‐dominated and natural areas by waterbirds as dispersal vectors. This spatial study highlights the importance of non‐frugivorous birds for long‐distance plant dispersal, which is generally an overlooked mechanism in studies aiming to predict and manage expansion of weed plants.

There will be conflict – agricultural landscapes are prime, rather than marginal, habitats for Asian elephants

AbstractMisconceptions about species’ ecological preferences compromise conservation efforts. Whenever people and elephants share landscapes, human–elephant conflicts (HEC) occur in the form of crop raiding, elephant attacks on people and retaliatory actions from people on elephants. HEC is considered the main threat to the endangered Asian elephant Elephas maximus. Much of HEC mitigation in Asia is based on rescuing elephants from conflict areas and returning them to nature, for example, by means of ‘problem elephant’ translocation. Here, we used two independent and extensive datasets comprising elephant GPS telemetry and HEC incident reports to assess the relationship between elephant habitat preferences and the occurrence of HEC at a broad spatial scale in Peninsular Malaysia. Specifically, we assessed (a) the habitat suitability of agricultural landscapes where HEC incidents occur and (b) sexual differences in habitat preferences with implications for HEC mitigation and elephant conservation. We found strong differences in habitat use between females and males and that the locations of HEC incidents were areas of very high habitat suitability for elephants, especially for females. HEC reports suggest that in Peninsular Malaysia females are involved in more crop damage conflicts than males, whereas males are more prone to direct encounters with people. Our results show that human‐dominated landscapes are prime elephant habitat, and not merely marginal areas that elephants use in the absence of other options. The high ecological overlap between elephants and people means that conflict will continue to happen when both species share landscapes. HEC mitigation strategies, therefore, cannot be based on elephant removal (e.g. translocation) and need to be holistic approaches that integrate both ecological and human social dimensions to promote tolerated human–elephant coexistence.

Seasonal and daily activity patterns by Eleonora’s FalconFalco eleonoraebased on GPS telemetry: a contribution to the species’ movement ecology at its breeding grounds

SummaryEleonora’s FalconFalco eleonoraeis a migratory raptor, well-known for its delayed breeding period. Owing to its great mobility, current information on its distribution pattern during the pre-breeding period is rather sporadic, mainly based on field observations and only one telemetry study. Likewise, the species’ ranging activity during the breeding period has not been thoroughly investigated due to methodological limitations of the approaches implemented in previous studies, again amounting to only two telemetry studies in recent years. In this study we aimed to provide a comprehensive overview of the species’ ranging activity at its breeding grounds based on telemetry. Utilizing GPS data from six adult females originating from the core of the species’ breeding range we explored broad- and fine-scale activity patterns while at their breeding grounds. Our results indicated that during the pre-breeding period the falcons visited high biodiversity areas lying hundreds of kilometres away from their colonies, exhibiting site-fidelity, as shown for falcons from other breeding colonies in the past. During the breeding period the falcons roamed at an average distance of 17 km from their nesting sites, but their ranging activity could be observed up to 130 km. In accordance with the species’ breeding biology, the falcons tended to perform longer trips as the nestlings became more independent. The temporal pattern of ranging activity fitted well with the diurnal variability of the autumn migration flux. Furthermore, nest attendance tended to decrease in windy conditions and as the season progressed, and to increase when southerly winds blew. Despite the low number of tracked falcons, our study set a reference basis for future studies highlighting the importance of specific (protected) areas during the pre-breeding period and providing the first assessment of the movement ecology of the species during the pre-breeding and breeding period in Greece.

Space use by a male Andean bear (Tremarctos ornatus) tracked with GPS telemetry in the Macizo Chingaza, Cordillera Oriental of the Colombian Andes

Notas sobre Mamíferos Sudamericanos es una revista de la Sociedad Argentina para el Estudio de los Mamíferos (SAREM). Publica información acotada donde se describen nuevas localidades de registro, datos sobre comportamiento y aspectos ecológicos de mamíferos neotropicales.

Felid bedrooms with a panoramic view: selection of resting sites by Eurasian lynx (Lynx lynx) in a karstic landscape

Eurasian lynx (Lynx lynx) is a crepuscular-nocturnal carnivore and mostly spends daytime resting. Although resting sites represent an important part of the lynx habitat and can be negatively affected by human activities, it is still poorly known how lynx select these sites, especially in regions with rugged topography characteristic for much of the species’ range. We analysed microscale habitat selection of lynx resting sites at the home-range level in a karstic landscape of the Dinaric Mountains, Slovenia, using a use-availability study design. We also searched for differences in the selection of resting sites in respect to the presence of ungulate kills, which often limit the available resting sites during the prey-consumption period. Using generalised linear mixed models (GLMM), we tested which environmental features and human infrastructure are important for lynx when choosing resting sites. Lynx selected mountain ridges and hilltops, as well as locations with steeper slopes and lower local visibility. Such locations likely provide concealment from potential danger or prey and, at the same time, offer good overview of the surroundings. There was also a tendency to avoid forest cabins and to select rocky terrain and southern exposures, but support in the data for this was lower. When lynx were not limited by the presence of fresh kill, the selection tended to be stronger, but the differences were not significant, except for visibility, which was lower at resting sites near prey remains. Results likely reflect high availability of suitable resting sites in a rugged terrain of karstic landscape. Animals are often most vulnerable during sleep, thus the resting site should ideally provide them with cover to reduce exposure and at the same time give them good overview of the surroundings to detect any approaching danger. We used snow tracking and GPS telemetry, for the first time in combination with data from activity sensors, to reliably determine resting sites of Eurasian lynx in a rugged karstic landscape. We showed how lynx face the trade-off of the need to be concealed, yet at the same time attain good view, by selecting structured microhabitats on top of the ridges and on steep slopes. Our results also suggest that in the regions with rugged terrain the influence of human infrastructure might be lower compared to the study areas of previous research.

Satellite-based habitat monitoring reveals long-term dynamics of deer habitat in response to forest disturbances.

Disturbances play a key role in driving forest ecosystem dynamics, but how disturbances shape wildlife habitat across space and time often remains unclear. A major reason for this is a lack of information about changes in habitat suitability across large areas and longer time periods. Here, we use a novel approach based on Landsat satellite image time series to map seasonal habitat suitability annually from 1986 to 2017. Our approach involves characterizing forest disturbance dynamics using Landsat-based metrics, harmonizing these metrics through a temporal segmentation algorithm, and then using them together with GPS telemetry data in habitat models. We apply this framework to assess how natural forest disturbances and post-disturbance salvage logging affect habitat suitability for two ungulates, roe deer (Capreolus capreolus) and red deer (Cervus elaphus), over 32yr in a Central European forest landscape. We found that red and roe deer differed in their response to forest disturbances. Habitat suitability for red deer consistently improved after disturbances, whereas the suitability of disturbed sites was more variable for roe deer depending on season (lower during winter than summer) and disturbance agent (lower in windthrow vs. bark-beetle-affected stands). Salvage logging altered the suitability of bark beetle-affected stands for deer, having negative effects on red deer and mixed effects on roe deer, but generally did not have clear effects on habitat suitability in windthrows. Our results highlight long-lasting legacy effects of forest disturbances on deer habitat. For example, bark beetle disturbances improved red deer habitat suitability for at least 25yr. The duration of disturbance impacts generally increased with elevation. Methodologically, our approach proved effective for improving the robustness of habitat reconstructions from Landsat time series: integrating multiyear telemetry data into single, multi-temporal habitat models improved model transferability in time. Likewise, temporally segmenting the Landsat-based metrics increased the temporal consistency of our habitat suitability maps. As the frequency of natural forest disturbances is increasing across the globe, their impacts on wildlife habitat should be considered in wildlife and forest management. Our approach offers a widely applicable method for monitoring habitat suitability changes caused by landscape dynamics such as forest disturbance.