Effects of Species Behavior on Global Positioning System Collar Fix Rates

ABSTRACT Use of Global Positioning System (GPS) telemetry is increasing in wildlife studies and has provided researchers and managers with new insight into animal behavior. However, performance of GPS collars varies and a major concern is the cause of unsuccessful fixes. We examined possible factors causing missed fixes in GPS collars on sympatric free-ranging Eurasian lynx (Lynx lynx) and wolverines (Gulo gulo) in northern Sweden. We tested for effects of species, activity, habitat, individual, and collar on fix rate. Species was the most important factor affecting fix rate. Fix rate of GPS collars on lynx (80%) was almost twice as high as on wolverines (46%). Fix rate decreased during periods of low activity (day beds) for both species. Fix rate also decreased for females (both lynx and wolverine) for a period after they gave birth. We found no effect of proportion of forest within individual home range on fix rate. We conclude that species behavior, characteristics, and activity pattern are important factors affecting fix rate that we recommend be taken into consideration prior to analyzing GPS location data.     

Grizzly Bear Behavior and Global Positioning System Collar Fix Rates

Abstract: Animal locations collected by Global Positioning System (GPS) collars will represent a biased sample of the sites an animal used if some position fixes fail and if those missed locations do not occur randomly. Probability of a GPS receiver obtaining a position fix is known to decline as canopy cover increases, but the impact of forest canopy cover was insufficient to account for the low fix rates we observed for GPS collars on grizzly bears (Ursus arctos). We tested the hypothesis that GPS fix rates were related to the interaction between animal activity (active vs. resting) and canopy cover by evaluating the following predictions: 1) grizzly bear activity should follow a circadian pattern similar to the circadian fix-rate pattern, 2) grizzly bear use of canopy cover should follow a circadian pattern similar to the circadian fix rates, 3) grizzly bear activity should be related to canopy cover (i.e., bears should rest in areas with relatively high canopy covers and feed and move in relatively open areas), and 4) collar orientation and canopy cover should interact to affect the fix rates of test collars. The GPS fix rates traced a bimodal circadian pattern that was directly related to the circadian pattern of grizzly bear activity. Fix rates declined when bears were more likely to be using denser cover, and fix rates of test collars demonstrated that collar orientation interacted with canopy cover, such that fix rates declined much more with increasing canopy cover when the collar was on its side than when the collar was upright. We concluded that inferences made about grizzly bear microhabitat use, based on GPS locations, will underrepresent high canopy cover sites, especially when grizzly bears are resting there. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):596–602; 2008)     

Fix Success and Accuracy of Global Positioning System Collars in Old-Growth Temperate Coniferous Forests

Abstract: Global Positioning System (GPS) telemetry is used extensively to study animal distribution and resource selection patterns but is susceptible to biases resulting from data omission and spatial inaccuracies. These data errors may cause misinterpretation of wildlife habitat selection or spatial use patterns. We used both stationary test collars and collared free-ranging American black bears (Ursus americanus) to quantify systemic data loss and location error of GPS telemetry in mountainous, old-growth temperate forests of Olympic National Park, Washington, USA. We developed predictive models of environmental factors that influence the probability of obtaining GPS locations and evaluated the ability of weighting factors derived from these models to mitigate data omission biases from collared bears. We also examined the effects of microhabitat on collar fix success rate and examined collar accuracy as related to elevation changes between successive fixes. The probability of collars successfully obtaining location fixes was positively associated with elevation and unobstructed satellite view and was negatively affected by the interaction of overstory canopy and satellite view. Test collars were 33% more successful at acquiring fixes than those on bears. Fix success rates of collared bears varied seasonally and diurnally. Application of weighting factors to individual collared bear fixes recouped only 6% of lost data and failed to reduce seasonal or diurnal variation in fix success, suggesting that variables not included in our model contributed to data loss. Test collars placed to mimic bear bedding sites received 16% fewer fixes than randomly placed collars, indicating that microhabitat selection may contribute to data loss for wildlife equipped with GPS collars. Horizontal collar errors of >800 m occurred when elevation changes between successive fixes were >400 m. We conclude that significant limitations remain in accounting for data loss and error inherent in using GPS telemetry in coniferous forest ecosystems and that, at present, resource selection patterns of large mammals derived from GPS telemetry should be interpreted cautiously.     

Testing VHF/GPS Collar Design and Safety in the Study of Free-Roaming Horses

Effective and safe monitoring techniques are needed by U.S. land managers to understand free-roaming horse behavior and habitat use and to aid in making informed management decisions. Global positioning system (GPS) and very high frequency (VHF) radio collars can be used to provide high spatial and temporal resolution information for detecting free-roaming horse movement. GPS and VHF collars are a common tool used in wildlife management, but have rarely been used for free-roaming horse research and monitoring in the United States. The purpose of this study was to evaluate the design, safety, and detachment device on GPS/VHF collars used to collect free-roaming horse location and movement data. Between 2009 and 2010, 28 domestic and feral horses were marked with commercial and custom designed VHF/GPS collars. Individual horses were evaluated for damage caused by the collar placement, and following initial observations, collar design was modified to reduce the potential for injury. After collar modifications, which included the addition of collar length adjustments to both sides of the collar allowing for better alignment of collar and neck shapes, adding foam padding to the custom collars to replicate the commercial collar foam padding, and repositioning the detachment device to reduce wear along the jowl, we observed little to no evidence of collar wear on horses. Neither custom-built nor commercial collars caused injury to study horses, however, most of the custom-built collars failed to collect data. During the evaluation of collar detachment devices, we had an 89% success rate of collar devices detaching correctly. This study showed that free-roaming horses can be safely marked with GPS and/or VHF collars with minimal risk of injury, and that these collars can be a useful tool for monitoring horses without creating a risk to horse health and wellness.     

Improving the accuracy of estimates of animal path and travel distance using GPS drift‐corrected dead reckoning

Route taken and distance travelled are important parameters for studies of animal locomotion. They are often measured using a collar equipped with GPS. Collar weight restrictions limit battery size, which leads to a compromise between collar operating life and GPS fix rate. In studies that rely on linear interpolation between intermittent GPS fixes, path tortuosity will often lead to inaccurate path and distance travelled estimates. Here, we investigate whether GPS‐corrected dead reckoning can improve the accuracy of localization and distance travelled estimates while maximizing collar operating life. Custom‐built tracking collars were deployed on nine freely exercising domestic dogs to collect high fix rate GPS data. Simulations were carried out to measure the extent to which combining accelerometer‐based speed and magnetometer heading estimates (dead reckoning) with low fix rate GPS drift correction could improve the accuracy of path and distance travelled estimates. In our study, median 2‐dimensional root‐mean‐squared (2D‐RMS) position error was between 158 and 463 m (median path length 16.43 km) and distance travelled was underestimated by between 30% and 64% when a GPS position fix was taken every 5 min. Dead reckoning with GPS drift correction (1 GPS fix every 5 min) reduced 2D‐RMS position error to between 15 and 38 m and distance travelled to between an underestimation of 2% and an overestimation of 5%. Achieving this accuracy from GPS alone would require approximately 12 fixes every minute and result in a battery life of approximately 11 days; dead reckoning reduces the number of fixes required, enabling a collar life of approximately 10 months. Our results are generally applicable to GPS‐based tracking studies of quadrupedal animals and could be applied to studies of energetics, behavioral ecology, and locomotion. This low‐cost approach overcomes the limitation of low fix rate GPS and enables the long‐term deployment of lightweight GPS collars.     

Comparative Performance of Three Brands of Lightweight Global Positioning System Collars

ABSTRACT Recent miniaturization and weight reductions of Global Positioning System (GPS) collars have opened up deployment opportunities on a new array of terrestrial animal species, but the performance of lightweight (<90 g) GPS collars has not been evaluated. I examined the success of 42 GPS collars from 3 manufacturers (Televilt/TVP Positioning, AB, Lindesburg, Sweden; Sirtrack Ltd., Havelock North, New Zealand; H.A.B.I.T [HABIT] Research Ltd., Victoria, BC, Canada) in stationary, open-sky conditions and during deployments on brushtail possums (Trichosurus vulpecula), a nocturnal arboreal marsupial. I assessed performance of these collars in terms of technical malfunctions, fix-success rates, battery longevity, and aspects of location quality. Technical malfunctions occurred in >50% of HABIT and Televilt collars, whereas all Sirtrack collars operated normally. Fix-success rates for all brands were significantly higher during stationary tests than when deployed on brushtail possums. HABIT and Televilt brands functioned poorly in field conditions, with success rates of 16.2% and 2.1%, respectively. Sirtrack collars had the highest fix rate when deployed (64.8%). I modified several HABIT collars by changing the GPS antenna location, with a resultant substantial increase in field fix success (92.6%). Most collars ceased working before they reached 50% of their manufacturer-estimated life expectancy. Suboptimal placement of GPS antenna, combined with short satellite acquisition times and long fix intervals, were a likely cause of low fix-success rates and premature battery failures. Researchers wanting to employ lightweight GPS collars must be aware of current limitations and should carefully consider prospects of low fix rates and limited battery lives before deciding whether these units are capable of meeting study objectives.     

Testing Global Positioning System Telemetry to Study Wolf Predation on Deer Fawns

ABSTRACT We conducted a pilot study to test the usefulness of Global Positioning System (GPS) collars for investigating wolf (Canis lupus) predation on white-tailed deer (Odocoileus virginianus) fawns. Using GPS collars with short location-attempt intervals on 5 wolves and 5 deer during summers 2002–2004 in northeastern Minnesota, USA, demonstrated how this approach could provide new insights into wolf hunting behavior of fawns. For example, a wolf traveled ≥1.5–3.0 km and spent 20–22 hours in the immediate vicinity of known fawn kill sites and ≥0.7 km and 8.3 hours at scavenging sites. Wolf travel paths indicated that wolves intentionally traveled into deer summer ranges, traveled ≥0.7–4.2 km in such ranges, and spent <1–22 hours per visit. Each pair of 3 GPS-collared wolf pack members were located together for ≤6% of potential locations. From GPS collar data, we estimated that each deer summer range in a pack territory containing 5 wolves ≥1 year old and hunting individually would be visited by a wolf on average every 3–5 days. This approach holds great potential for investigating summer hunting behavior of wolves in areas where direct observation is impractical or impossible.     

Performance of Spread Spectrum Global Positioning System Collars on Grizzly and Black Bears

ABSTRACT Global Positioning System (GPS) telemetry is a prevalent tool now used in the study of large mammals. Global Positioning Systems either store the data on board the collar or contain a remote-transfer system that allows for data recovery at more frequent intervals. Spread spectrum (S-S) technology is a new mode of data transfer designed to overcome interference problems associated with narrow-band very high frequency and ultra high frequency data-transfer systems. We evaluated performance of S-S GPS radiocollars deployed on grizzly (Ursus arctos) and black bears (U. americanus). We also evaluated variables that influenced GPS fix success rates, with particular focus on animal activity, time of year, and temperature. The S-S GPS collars performed to our expectations and met study objectives; we did not experience any major problems with the data-transfer system. We observed varying rates of fix success that were directly related to recorded activity counts. Using logistic regression, we verified that activity counts were a reasonable measure of resting or feeding-traveling in both bear species. Our results showed that 73% and 79% of missed fixes, respectively, occurred when we predicted black and grizzly bears to be resting. Temperatures measured in the canister of the collar were not correlated with air temperature, suggesting posture and activity influenced canister temperature. Both measures of temperature were predictive of fix success. We did not find that fix success was related to body morphology (i.e., neck circumference, mass, and chest girth), fix interval, position of the GPS antenna relative to the sky, or sex of the bear. We conclude that fix success for both species is strongly related to activity patterns and time of year. Activity counters appear to be a reasonable measure of this behavior, and we recommend researchers consider including an activity-count system when deploying GPS collars. We also recommend researchers explore building separate models of habitat selection based upon categories of activity to account for bias in fix success associated with bear behavior.     

不同坡位对GPS项圈定位性能的影响

GPS项圈已广泛应用于大中型野生动物的野外定位监测,支持野生动物生态学研究和保护管理规划.但由于地形等因素影响,GPS项圈返回的数据可能有定位误差和定位数据缺失偏歧.因此,在进行生境选择等相关生态学研究之前,应对GPS项圈的定位性能进行评估.本研究于2019年11月至2020年10月,在云南大理苍山5个测试点各静态放置...     

Studies on the in vitro formation of periostracum inHelisoma duryi: the influence of brain

Summary Excised mantle tissue produces periostracum when placed in organ culture. Mantle collars taken from animals exhibiting a fast rate of shell deposition in vivo produce more periostracum than mantle collars from slow growing animals. The addition of a brain from a fast growing animal increased periostracum production by a mantle collar from a slow growing animal. This effect was enhanced by removing the cerebral ganglia lateral lobes. This suggests that a factor(s) is present in the brain of fast growing animals which enhances periostracum formation in vitro. The lateral lobes appear to inhibit this activity. Radiolabel incorporation studies suggest that the periostracum produced by fast growing animals has a higher glycine content than that produced by slow growing animals.Abbreviations Dopa 3,4-dihydroxyphenylalanine - FB brain derived from a fast growing animal - FMC mantle collar derived from a fast growing animal - LL lateral lobes - LL lateral lobes removed - MC mantle collar - SB brain derived from a slow growing animal - SGPF shell growth promoting factor - SMC mantle collar derived from a slow growing animal - TCA trichloroacetic acid - WM whole mantle     

Are All Global Positioning System Collars Created Equal? Correcting Habitat-Induced Bias Using Three Brands in the Central Canadian Rockies

Abstract: Global positioning system (GPS) collars are changing the face of wildlife research, yet they still possess biases such as habitat-induced fix-rate bias, which is a serious concern for habitat selection studies. We studied GPS bias in the Central Canadian Rockies, a critical area for wildlife conservation, to provide a statistical approach to correct GPS habitat bias for habitat selection studies using GPS collars. To model GPS habitat bias we deployed 11 different collars from 3 brands of GPS collars (Advanced Telemetry Systems [ATS], Asanti, MN; LOTEK Engineering Ltd., Newmarket, ON, Canada; and Televilt, Lindesberg, Sweden) in a random-stratified design at 86 sites across habitat and topographic conditions. We modeled the probability of obtaining a successful location, P_FIX, as a function of habitat, topography, and collar brand using mixed-effects logistic regression in an information theoretic approach. For LOTEK collars, we also investigated the effect of 8 and 12 GPS channels on fix rate. The ATS collars had the highest overall fix rates (97.4%), followed by LOTEK 12 channel (94.5%), LOTEK 8 channel (85.6%), and Televilt (82.3%). Sufficient model selection uncertainty existed to warrant model averaging for logistic regression P_FIX models. Collar brand influenced fix rate in all P_FIX models: fix rates for ATS and LOTEK 12 channel were not statistically different, whereas LOTEK 8 channel receivers had intermediate fix rates, and Televilt had the lowest. Fix rate was reduced in aspen stands, closed coniferous stands, and sites in narrow mountainous valleys but was higher on upper mountain slopes. Slight discrepancies between fix rates from field trials and observed species fix rates (wolf [Canis lupus] and elk [Cervus elaphus]) suggest uncorrected behavioral or movement-induced bias similar to other recent studies. Regardless, the strong habitat-induced bias in GPS fix rates confirms that in our study area habitat effects are critical, especially for poorer performance brands. Based on previous studies of effects of the amount of bias on inferences, our results suggest correction for GPS bias should be mandatory for Televilt collars in the Canadian Rockies, optional for LOTEK (dependent on the no. of channels), and unnecessary for ATS. Thus, our GPS bias model will be useful to researchers using GPS collars on a variety of species throughout the Rocky Mountain cordillera.     

Accuracy,Precision, and Observation Rates of Global Positioning System Telemetry Collars

ABSTRACT We addressed concerns regarding performance of various Global Positioning System (GPS) collar configurations for describing habitat use by Rocky Mountain elk (Cervus elaphus) in rugged, forested terrain. We tested 8 GPS collars (Lotek Wireless, Newmarket, ON, Canada) in 4 different model and equipment configurations at 2 reference points (an open hilltop and a forested ravine) to determine habitat-specific differences in performance among collar configurations. We then placed individual collars at 60 additional points that were stratified randomly among 4 canopy-cover classes and 3 classes of available sky. All collars exhibited a locational bias of 4 m horizontally west and of 10 m vertically below a reference standard established by position-averaging with a handheld receiver (Garmin 12MAP) calibrated at National Geodetic Survey benchmarks. The GPS collar models that were programmed for longer satellite-acquisition times provided greater location precision than models that had been programmed for short acquisition times to preserve battery power. Canopy cover and available sky had a greater effect on collar location precision and observation rates than slope, slope position, aspect, conifer basal area, tree height, canopy depth, or elevation. Researchers should test collars at known reference points to confirm that location precision and rates of observation are adequate for their particular study objectives. Manufacturers of GPS collars should inform clients of their programming criteria for acquisition time so that customers can make informed decisions regarding trade-offs between precision of locations, data quantity, and battery life.     

GPS telemetry of forest elephants in Central Africa: results of a preliminary study

Few data exist on the ranging behaviour of forest elephants. A feasibility study on the use of GPS telemetry as a tool to study ranging, seasonal movements and distribution was implemented in the Dzanga‐Sangha and Nouabalé‐Ndoki National Parks Complex of Central African Republic and Congo. The study consisted of two parts – a thorough hand‐held testing of an elephant GPS telemetry collar under tropical forest conditions and the deployment of collars on two elephants. During the feasibility study the system performance was satisfactory; GPS fix acquisition success rate, VHF and UHF collar–researcher communications were adequate. Two elephants, a mature bull and an adult female, were immobilized and fitted with GPS collars in October 1998. After deployment, the female's GPS collar performed well initially, but in less than a month the GPS within the collar stopped acquiring fixes. She was subsequently located using VHF tracking. The male was never relocated strongly suggesting complete failure of the collar. Despite these setbacks, the small amount of data retrieved provide an important first insight into forest elephant ranging and daily activity patterns, with significant conservation implications. When technical difficulties of reliability are overcome, GPS telemetry will provide an exceptionally useful tool in forest elephant research and management.     

Restraint collars. Part I: Elizabethan collars and other types of restraint collars

Restraint collars can provide an investigator with a noninvasive means to prevent certain undesirable behaviors and provide a clinician with a nonpharmaceutical method to prevent an animal from inflicting self-injury; without proper use and monitoring, however, these collars can do more harm than good. This first part of our look at restraint collars introduces collar types and proper use. Next month's installment will review specific issues associated with the use of different types of collars for different species.     

A note on the circadian rhythm and feeding behaviour of sheep fitted with a lightweight GPS collar

The circadian rhythm and feeding behaviour (bite rate) of 16 Scottish Blackface ewes of which eight were fitted with a lightweight (863 g) GPS collar were examined. The collar consisted of a leather harness and a 0.5 l aluminium box and represented 2.2% of the average body mass of the study ewes. No differences in circadian rhythm and bite rate were found between ewes fitted with the collars and ewes that were not. The relevance of using collar weight as a proportion of body mass as a guide to gauge its impact on the feeding behaviour of small ruminant (35–75 kg) herbivores is questioned.     

Comparing Global Positioning System and Very High Frequency Telemetry Home Ranges of White-Tailed Deer

ABSTRACT Use of Global Positioning System (GPS) collars on free-ranging ungulates overcomes many limitations of conventional very high frequency (VHF) telemetry and offers a practical means of studying space use and home range estimation. To better understand winter home ranges of white-tailed deer (Odocoileus virginianus), we evaluated GPS collar performance, and we compared GPS- and VHF-derived diurnal home ranges (for the same animals) and GPS-derived home range estimates for diurnal and nocturnal locations. Overall, the mean fix success rate of our GPS collars was 85% (range = 14–99%). Kernel density estimates of home range (using the 95% probability contour) derived from GPS and VHF locations were generally similar, as were GPS-derived diurnal and nocturnal home ranges. Overlap indices between GPS and VHF utilization distributions (UDs) ranged from 0.49 to 0.78 for the volume of intersection (VI) index and from 0.67 to 0.94 for Bhattacharyya's affinity (BA); overlap indices for GPS-diurnal and nocturnal UDs ranged from 0.29 to 0.81 for VI and from 0.56 to 0.94 for BA. Despite similarities of home ranges estimated from GPS versus VHF locations and GPS-diurnal versus nocturnal locations, our data also indicate that differences may have important implications for studies focused on deer use of space, habitat, and resources at a finer scale.     

Low-Cost Global Positioning System Harness for Pampas Deer

ABSTRACT Global Positioning System (GPS) collars have proven to be an efficient tool for studying wildlife. However, this technique generally requires great investment in material, which notwithstanding its possible cost-effectiveness, is still beyond the means of most of the scientific community in developing countries. We developed and applied a low-cost GPS harness system placed on pampas deer (Ozotoceros bezoarticus) in the Central Pantanal of Brazil and compared costs of our technique to other commonly manufactured GPS collar systems. Of the 19 GPS harness attached to deer, 8 failed to obtain data series. For the remaining 11 animals, we stored 31,596 locations at 5-minute and 10-minute fix interval schedules (<120 days of continuous monitoring). Monitoring period of each animal lasted from 4.5 days to 17.4 days. Location error tested with a stationary GPS receiver was >3.7 m for 95% of locations. Rate of fixes acquired on the programmed schedule after correcting for errors was 98.5%. Compared to the 4 most used GPS radiocollar manufacturers, cost per fix of the GPS harness we developed was >50% of the cost per fix of the cheapest available product, although our modified device was heavier than all available products for medium-sized deer. Our approach was cost-effective to generate reliable information about activity patterns of pampas deer and may represent an alternative technique, especially for researchers in underdeveloped countries.     

Badgers prefer cattle pasture but avoid cattle: implications for bovine tuberculosis control

Effective management of infectious disease relies upon understanding mechanisms of pathogen transmission. In particular, while models of disease dynamics usually assume transmission through direct contact, transmission through environmental contamination can cause different dynamics. We used Global Positioning System (GPS) collars and proximity‐sensing contact‐collars to explore opportunities for transmission of Mycobacterium bovis [causal agent of bovine tuberculosis] between cattle and badgers (Meles meles). Cattle pasture was badgers’ most preferred habitat. Nevertheless, although collared cattle spent 2914 collar‐nights in the home ranges of contact‐collared badgers, and 5380 collar‐nights in the home ranges of GPS‐collared badgers, we detected no direct contacts between the two species. Simultaneous GPS‐tracking revealed that badgers preferred land > 50 m from cattle. Very infrequent direct contact indicates that badger‐to‐cattle and cattle‐to‐badger M. bovis transmission may typically occur through contamination of the two species’ shared environment. This information should help to inform tuberculosis control by guiding both modelling and farm management.     

Assessment of a livestock GPS collar based on an open‐source datalogger informs best practices for logging intensity

Ecologists have used Global Positioning Systems (GPS) to track animals for 30 years. Issues today include logging frequency and precision in estimating space use and travel distances, as well as battery life and cost. We developed a low‐cost (~US$125), open‐source GPS datalogger based on Arduino. To test the system, we collected positions at 20‐s intervals for several 1‐week durations from cattle and sheep on rangeland in North Dakota. We tested two questions of broad interest to ecologists who use GPS collars to track animal movements: (1) How closely do collared animals cluster in their herd? (2) How well do different logging patterns estimate patch occupancy and total daily distance traveled? Tested logging patterns included regular logging (one position every 5 or 10 min), and burst logging (positions recorded at 20‐s intervals for 5 or 10 min per hour followed by a sleep period). Collared sheep within the same pasture spent 75% of daytime periods within 51 m of each other (mean = 42 m); collared cattle were within 111 m (mean = 76 m). In our comparison of how well different logging patterns estimate space use versus constant logging, the proportion of positions recorded in 1‐ and 16‐ha patches differed by 2%–3% for burst logging and 1% for regular logging. Although all logging patterns underestimated total daily distance traveled, underestimations were corrected by multiplying estimations by regression coefficients estimated by maximum likelihood. Burst logging can extend battery life by a factor of 7. We conclude that a minimum of two collars programmed with burst logging robustly estimate patch use and spatial distribution of grazing livestock herds. Research questions that require accurately estimating travel of individual animals, however, are probably best addressed with regular logging intervals and will thus have greater battery demands than spatial occupancy questions across all GPS datalogger systems.     

Measuring Daily Ranging Distances of <Emphasis Type="Italic">Rhinopithecus bieti</Emphasis> via a Global Positioning System Collar at Jinsichang,China: A Methodological Consideration

There are few data on the daily ranging distances of Yunnan snub-nosed monkeys (Rhinopithecus bieti). We fitted 1 adult male from a natural group at Jinsichang in China’s Yunnan Province with a global positioning system (GPS) collar and tracked him from December 2003 to October 2004 to estimate the daily ranging distances of the group. The total acquisition rate of the GPS collar was 82.2%, which indicates that one can use GPS collars to track the species efficiently in high-altitude, temperate, coniferous forest. We obtained group locations or fixes at 5 predetermined times during the day. The sleeping sites of the subjects are the key points to estimate the day range. We compared 2 measures of day range: the 2-point straight-line displacement and the multipoint cumulative daily ranging distance. Straight-line displacement between 2 consecutive mornings or 2 consecutive evenings can substitute for that between the morning sleeping site and the evening sleeping site. In general, the group does not move at night. The 2 measures of day range yielded different results. The multipoint cumulative daily ranging distance was the method of choice to measure their daily travel costs. The minimum required number of fixes per day was 3. Per statistical evidence, the number of full-day group follows per month influences the estimate of day range of the group and ≥10 d is required to obtain a reliable estimate; 5 d per month might not be enough. We dealt mainly with the methodologic aspects of day range calculations. We did not address functional aspects on the estimate of day range, viz. the influence of vegetation, food distribution patterns, climate change, seasonality, and the monkey group itself.