scholarly journals Population characteristics, space use and habitat selection of two non-migratory caribou herds in central Alaska, 1994 - 2009

Rangifer ◽  
2014 ◽  
Vol 34 (1) ◽  
pp. 1 ◽  
Author(s):  
Jon S. Horne ◽  
Tim Craig ◽  
Kyle Joly ◽  
Glenn W. Stout ◽  
Merben R. Cebrian ◽  
...  

Conservation and management of Alaska’s caribou (Rangifer tarandus granti) herds are important for ecological, cultural, social, and economic reasons.  While most research is directed towards the large migratory herds, smaller herds that may or may not be migratory can be an equally valuable component of the state’s faunal resources; but for many of these smaller herds, basic information on herd size, demographics, space use and movements is lacking.  We compiled Very High Frequency (VHF) telemetry data collected from 1994 - 2009 on 2 such herds in central Alaska, the Hodzana Hills Herd (HHH) and the Ray Mountain Herd (RMH) and estimated abundance, survival, resource selection and seasonal home ranges to inform future management of these herds.  We found that both herds were relatively small and stable with approximately 1000 – 1500 individuals; annual survivorship of adult females was high (93% and 94% for RMH and HHH, respectively) and comparable to other stable or increasing herds in Alaska.  Both herds were non-migratory maintaining seasonal ranges with substantial overlap.  Additionally, despite their close proximity, we did not document any exchange of individuals between the 2 herds.  Their spatial separation may be partly due to a strip of non-preferred habitat that somewhat parallels the Dalton Highway.  While the telemetry data we used were not originally collected for the purpose of this study, careful compilation and application of appropriate analytical techniques allowed us to glean important characteristics of these herds that will be of value to regulatory and management agencies in the future.

2020 ◽  
Vol 98 (11) ◽  
pp. 751-760
Author(s):  
J.A. Silva ◽  
S.E. Nielsen ◽  
P.D. McLoughlin ◽  
A.R. Rodgers ◽  
C. Hague ◽  
...  

By regulating successional dynamics in Canada’s boreal forest, fires can affect the distribution of the Threatened woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)). Caribou tend to avoid areas burned within the last 40 years; however, few studies have compared pre-fire and post-fire caribou observations. In this study, we used caribou GPS locations from the Boreal Shield of Saskatchewan, Canada, to assess the short-term response of caribou to areas that burned while they were collared (hereafter recent burns). We used a “before–after, control–impact” design to compare the overlap of pre-fire and post-fire seasonal home ranges to the overlap of year-to-year seasonal home ranges. Caribou rarely encountered recent burns and when they did, they adjusted their space use in variable and complex ways that were largely indistinguishable from regular, interannual variation. Caribou tended to reduce use of recent burns in summer–autumn and winter, but not during the calving season, in some cases shifting their home range to incorporate more burned habitat. We conclude that recently burned areas (<5 years) may provide habitat value to woodland caribou, particularly during the calving season, requiring a more flexible approach to interpret fire in habitat management strategies.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2334
Author(s):  
James T. Johnson ◽  
Richard B. Chandler ◽  
L. Mike Conner ◽  
Michael J. Cherry ◽  
Charlie H. Killmaster ◽  
...  

Bait is often used to increase wildlife harvest susceptibility, enhance viewing opportunities, and survey wildlife populations. The effects of baiting depend on how bait influences space use and resource selection at multiple spatial scales. Although telemetry studies allow for inferences about resource selection within home ranges (third-order selection), they provide limited information about spatial variation in density, which is the result of second-order selection. Recent advances in spatial capture-recapture (SCR) techniques allow exploration of second- and third-order selection simultaneously using non-invasive methods such as camera traps. Our objectives were to describe how short-term baiting affects white-tailed deer (Odocoileus virginianus) behavior and distribution. We fit SCR models to camera data from baited and unbaited locations in southwestern Georgia to assess the effects of short-term baiting on second- and third-order selection of deer during summer and winter surveys. We found little evidence of second-order selection during late summer or early winter surveys when camera surveys using bait are typically conducted. However, we found evidence for third-order selection, indicating that resource selection within home ranges is affected. Concentrations in space use resulting from baiting may enhance disease transmission, change harvest susceptibility, and potentially bias the outcome of camera surveys using bait.


1985 ◽  
Vol 63 (3) ◽  
pp. 516-523 ◽  
Author(s):  
D. A. Gauthier ◽  
J. B. Theberge

Seasonal censuses (calving, rut, and winter periods) and other surveys were undertaken to apportion changes in mountain caribou (Rangifer tarandus caribou) numbers to changes in mortality, recruitment or ingress–egress, and to assess seasonal distribution. Data were collected from September 1978 to June 1982 in the St. Elias Mountains of the southwestern Yukon. Thirty-nine caribou were radiocollared and used in capture–recapture analysis. Estimates varied from a minimum herd size of 330 to a maximum of 560. Bulls comprised 33% of animals older than calves. Calving occurred between 15 May and 13 June from 1979 to 1982. Pregnancy rates varied from 78 to 82% during 1980 to 1982 while calves comprised 20% of the herd in calving periods, 19% during ruts, and 18% during midwinters. Recruitment (% yearlings) varied from 9% in 1980 to 13% in 1981 and 14% in 1982. Neonate mortality (birth to 3.5 weeks) varied from 13 to 49% between 1980 and 1982. An average of 56% of calves died within 5 months of birth. Natural mortality rates of adult–subadults varied between 6 and 9%. All evidence indicated stable or slowly increasing numbers until winter 1982 when movement from the study area was documented. The total range size was 1978 km2 with the herd occupying two distinct seasonal ranges in upland tundra plateaux separated by lowland boreal forest. Herd densities (based on seasonal range size) averaged 1.66 caribou/km2. The proportion of the herd in each upland area varied consistently between seasons and years such that variations in numbers could be accounted for by mortality, recruitment, and movement from the study area in the winter of 1982.


2017 ◽  
Author(s):  
Daniel W. Linden ◽  
Alexej P. K. Sirén ◽  
Peter J. Pekins

AbstractEstimating population size and resource selection functions (RSFs) are common approaches in applied ecology for addressing wildlife conservation and management objectives. Traditionally such approaches have been undertaken separately with different sources of data. Spatial capture-recapture (SCR) provides a framework for jointly estimating density and multi-scale resource selection, and data integration techniques provide opportunities for improving inferences from SCR models. Here we illustrate an application of integrated SCR-RSF modeling to a population of American marten (Martes americana) in alpine forests of northern New England. Spatial encounter data from camera traps were combined with telemetry locations from radio-collared individuals to examine how density and space use varied with spatial environmental features. We compared multi-model inferences between the integrated SCR-RSF model with telemetry and a standard SCR model with no telemetry. The integrated SCR-RSF model supported more complex relationships with spatial variation in third-order resource selection (i.e., individual space use), including selection for areas with shorter distances to mixed coniferous forest and rugged terrain. Both models indicated increased second-order selection (i.e., density) for areas close to mixed coniferous forest, while the integrated SCR-RSF model had a lower effect size due to modulation from spatial variability in space use. Our application of the integrated SCR-RSF model illustrates the improved inferences from spatial encounter data that can be achieved from integrating auxiliary telemetry data. Integrated modeling allows ecologists to join empirical data to ecological theory using a robust quantitative framework to better address conservation and management objectives.


2019 ◽  
Author(s):  
David C. McNitt ◽  
Robert S. Alonso ◽  
Michael J. Cherry ◽  
Michael L. Fies ◽  
Marcella J. Kelly

ABSTRACTBobcats are an apex predator and a species of socio-cultural importance in the central Appalachian Mountains. Despite their importance, knowledge of bobcat spatial ecology in the region is sparse. We examined space use and resource selection of bobcats in the Appalachian Mountains of western Virginia during 3 biological seasons: breeding (January-March), kitten-rearing (April-September), and dispersal (October-December). We observed sex effects on all space use metrics, with male seasonal areas of use (SAU) approximately 3 times larger than female SAUs and male movement rates 1.5 times higher than females during all seasons. We found no seasonal effect on SAU size for either sex. Female movement rates increased during the kitten-rearing season, and male movement rates increased during the dispersal season. We examined seasonal bobcat resource selection at 2 hierarchical scales, selection of home ranges within the landscape (2nd order) and selection of locations within home ranges (3rd order). Female bobcats exhibited 2nd order selection for higher elevations and deciduous forest and avoidance of fields. Males exhibited 2nd order selection for higher elevations and fields. Male 2nd order selection appears to be driven largely by the spatial distribution of females, which is mediated through the valley and ridge topography of the study area. Sample size precluded 3rd order analysis for females, however males exhibited 3rd order selection for higher elevations, fields, and deciduous forest. Resource selection patterns varied seasonally for both sexes, possibly driven by seasonal shifts in prey availability. Our findings highlight the importance of forested ridges to bobcats in the region. Our findings also illustrate the differences in space use between sexes, which future research efforts should consider. Further research should investigate seasonal shifts in bobcat prey selection, which may further explain the seasonal resource selection shifts we observed, and highlight potential implications for prey species.


2020 ◽  
Author(s):  
Joseph M. Eisaguirre ◽  
Travis L. Booms ◽  
Christopher P. Barger ◽  
Stephen B. Lewis ◽  
Greg A. Breed

AbstractIn populations of many taxa, a large fraction of sexually mature individuals do not breed but are attempting to enter the breeding population. Such individuals, often referred to as “floaters” play critical roles in determining dynamics and stability of these populations. Floaters are difficult to study, however, so we lack data on the roles they play in population ecology and conservation status of many species. Here, we paired satellite telemetry and a new mechanistic space use model based on an Ornstein-Uhlenbeck process to study the differential habitat selection and space use of floater and territorial golden eagles Aquila chrysaetos. Our sample consisted of 49 individuals tracked over complete breeding seasons across four years, totalling 104 eagle breeding seasons. Modeling these data with the new mechanistic approach was required to parse key differences in movement and separate aspects of resource selection from central place behavior. We found that floaters generally had more expansive space use patterns and larger home ranges, partitioning space with territorial individuals seemingly on fine scales through differential habitat and resource selection. Floater and territorial eagle home ranges overlapped markedly, suggesting floaters use the interstices between territories. Further, floater and territorial eagles differed in how they selected for uplift variables, key components of soaring birds’ energy landscape, with territorial eagles apparently better able to find and use thermal uplift. We also found relatively low individual heterogeneity in resource selection, especially among territorial individuals, suggesting a narrow realized niche for breeding individuals. This work furthers our understanding of floaters’ potential roles in population ecology of territorial species, as well as suggests that conserving landscapes occupied by territorial eagles also protects floaters.


Diversity ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 678
Author(s):  
Kate Twynham ◽  
Andrés Ordiz ◽  
Ole-Gunnar Støen ◽  
Geir-Rune Rauset ◽  
Jonas Kindberg ◽  
...  

In northern Eurasia, large carnivores overlap with semi-domestic reindeer (Rangifer tarandus) and moose (Alces alces). In Scandinavia, previous studies have quantified brown bear (Ursus arctos) spring predation on neonates of reindeer (mostly in May) and moose (mostly in June). We explored if habitat selection by brown bears changed following resource pulses and whether these changes are more pronounced on those individuals characterised by higher predatory behaviour. Fifteen brown bears in northern Sweden (2010–2012) were fitted with GPS proximity collars, and 2585 female reindeers were collared with UHF transmitters. Clusters of bear positions were visited to investigate moose and reindeer predation. Bear kill rates and home ranges were calculated to examine bear movements and predatory behaviour. Bear habitat selection was modelled using resource selection functions over four periods (pre-calving, reindeer calving, moose calving, and post-calving). Coefficients of selection for areas closer to different land cover classes across periods were compared, examining the interactions between different degrees of predatory behaviour (i.e., high and low). Bear habitat selection differed throughout the periods and between low and high predatory bears. Differences among individuals’ predatory behaviour are reflected in the selection of habitat types, providing empirical evidence that different levels of specialization in foraging behaviour helps to explain individual variation in bear habitat selection.


2018 ◽  
Vol 100 (1) ◽  
pp. 239-248
Author(s):  
Christopher R Anthony ◽  
Dana M Sanchez

2010 ◽  
Vol 365 (1550) ◽  
pp. 2221-2231 ◽  
Author(s):  
John G. Kie ◽  
Jason Matthiopoulos ◽  
John Fieberg ◽  
Roger A. Powell ◽  
Francesca Cagnacci ◽  
...  

Recent advances in animal tracking and telemetry technology have allowed the collection of location data at an ever-increasing rate and accuracy, and these advances have been accompanied by the development of new methods of data analysis for portraying space use, home ranges and utilization distributions. New statistical approaches include data-intensive techniques such as kriging and nonlinear generalized regression models for habitat use. In addition, mechanistic home-range models, derived from models of animal movement behaviour, promise to offer new insights into how home ranges emerge as the result of specific patterns of movements by individuals in response to their environment. Traditional methods such as kernel density estimators are likely to remain popular because of their ease of use. Large datasets make it possible to apply these methods over relatively short periods of time such as weeks or months, and these estimates may be analysed using mixed effects models, offering another approach to studying temporal variation in space-use patterns. Although new technologies open new avenues in ecological research, our knowledge of why animals use space in the ways we observe will only advance by researchers using these new technologies and asking new and innovative questions about the empirical patterns they observe.


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