scholarly journals Seasonal resource selection of woodland caribou (Rangifer tarandus caribou) across a gradient of anthropogenic disturbance

2016 ◽  
Vol 94 (2) ◽  
pp. 79-93 ◽  
Author(s):  
Megan L. Hornseth ◽  
Robert S. Rempel

Resource selection functions are useful tools for land-use planning, especially for wide-ranging species with sensitivity to anthropogenic disturbance. We evaluated five a priori hypotheses describing seasonal habitat selection of woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) across three regions in northern Ontario. Two regions were Boreal Shield dominated, one area with relatively high anthropogenic disturbance (due to commercial forestry) and the other with relatively low anthropogenic disturbance. The final region was located on the wetland-dominated Hudson Bay Lowlands. Each region encompassed two caribou management ranges: one was used for model development and the other for model evaluation. We developed seasonal resource selection probability functions using seasonal utilization distributions and isopleths derived from GPS collar data (from 212 caribou) to identify high- and low-use areas. We explored selection across five spatial scales; selection patterns were strongest at the 10 000 ha scale. We found temporal and spatial variations in all environmental predictors across ranges and seasons, especially in the Hudson Bay Lowlands. Our results consistently supported the integrated global model (with common variables but range-specific coefficients) where caribou habitat use is related to minimizing apparent competition with moose (Alces alces (L., 1758)) while avoiding disturbed areas, and utilizing areas with adequate forage.

2020 ◽  
Vol 98 (5) ◽  
pp. 331-341
Author(s):  
E.P. McNeill ◽  
I.D. Thompson ◽  
P.A. Wiebe ◽  
G.M. Street ◽  
J. Shuter ◽  
...  

Multi-scale selection patterns can be understood from two perspectives: coarse-scale patterns as the summation of fine-scale patterns (scaling-up), or as a hierarchy produced from multiple contributory factors with differential effects on organismal fitness (hierarchical). We examined woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) selection of foraging locations across two spatiotemporal scales to test whether selection patterns between them were consistent (scaling-up) or different (hierarchical) to determine which framework most accurately describes their foraging behaviour. Seven adult female woodland caribou were equipped with GPS telemetry radio collars outfitted with high-definition video cameras that recorded woodland caribou foraging choices throughout the summer. Fine-scale data from videos combined with direct measurements in the field along movement trajectories obtained from GPS fixes were used to estimate (i) feeding station selection and (ii) food patch selection. We estimated resource selection functions for each scale following a use–availability structure. Woodland caribou exhibited resource selection at both scales. Apart from selection for species of the lichen Cladina (Nyl.) Nyl. and patches associated with high abundance of Cladina, few patterns were consistent across both scales. Our study suggests that even at very fine scales, woodland caribou selection for foraging locations is hierarchical in nature.


1993 ◽  
Vol 71 (3) ◽  
pp. 487-493 ◽  
Author(s):  
Tony E. Chubbs ◽  
Lloyd B. Keith ◽  
Shane P. Mahoney ◽  
Michael J. McGrath

Movements, sex and age structure, and habitat selection of adult woodland caribou (Rangifer tarandus caribou) were examined in relation to clear-cutting on summer range in east-central Newfoundland during 1987 – 1990. We obtained 2473 locations of 35 radio-collared caribou during at least two consecutive summers. Locations relative to clearcuts were determined for eight males and 27 females. Distances to existing clearcuts were compared with distances to those same geographic points prior to and following the summer in which clear-cutting occurred. Four males and 10 females maintained similar mean distances from clearcuts, 3 males and 12 females were farther away, and 2 females were closer. Three other females and one male were assumed to be too distant to be affected by clear-cutting. Of those found farther away from clearcuts, females were 2 – 3 times farther away than males. Among female caribou that maintained similar mean distances to clearcuts, habitat use during clear-cutting was similar to that before and afterwards. Females displaced by clear-cutting avoided open burns and hardwoods and selected mature black-spruce forest, whereas prior to cutting they used habitats in proportion to their availability. Sex and age ratios indicated that significantly fewer females and calves were present near clearcuts than elsewhere in the study area. Our results demonstrate that clear-cutting mature forests on summer range may affect the movements and distribution of woodland caribou.


1988 ◽  
Vol 66 (2) ◽  
pp. 475-479 ◽  
Author(s):  
Murray W. Lankester ◽  
Stu Luttich

Fifty-eight percent of woodland caribou (Rangifer tarandus caribou) of the George River herd, Labrador, were infected with up to 110 giant American liver flukes (Fascioloides magna). The prevalence and intensity of infection did not differ between 2 sampling years or between sexes. Prevalence tended to increase with age while intensity did not differ among age groups. Liver weight increased with intensity of infection but condition, as measured by the mean depth of back fat, did not differ between infected and uninfected animals. Caribou must be considered a suitable host of F. magna since the growth and maturation of the parasite and lesions produced in Rangifer resemble those in deer and wapiti.


2012 ◽  
Vol 126 (1) ◽  
pp. 20 ◽  
Author(s):  
Rodney W. Brook ◽  
Kenneth F. Abraham ◽  
Kevin R. Middel ◽  
R. Kenyon Ross

Concern about declining populations of sea ducks counted on the wintering grounds prompted a survey of sea ducks on the breeding grounds in the Hudson Bay Lowlands of Ontario in spring 2009. We estimated densities of breeding scoters (Surf Scoter, Melanitta perspicillata, White-winged Scoter, M. fusca, and Black Scoter, M. americana) and found the average estimates of Surf Scoters (average = 0.11 indicated pairs/km2) and Black Scoters (average = 0.16 indicated pairs/km2) to be as high as some of the highest reported for North America. We also conducted a habitat association analysis using resource selection functions (RSF) for indicated pairs of all scoter species combined at a scale of 250 m. Breeding pairs of scoters in the Hudson Bay Lowlands appear to have an affinity for smaller wetlands (≤100 ha) disproportionate to what is available, also avoiding lakes (i.e., wetlands >100 ha). Pairs were also found in areas with less forest cover and fen area than was available. An estimate of the area under the curve of the receiver operating characteristic suggests that these habitat association models have some utility. Once tested and validated with surveys beyond the current study area, these models can be refined and used to predict habitat use by breeding pairs of scoters in the Hudson Bay Lowlands; this information will be particularly useful for population estimation and land use planning.


2008 ◽  
Vol 86 (8) ◽  
pp. 812-825 ◽  
Author(s):  
D. D. Gustine ◽  
K. L. Parker

Conservation planning for species of concern or importance can be aided by resource selection functions (RSFs) that identify important areas or attributes. Models that can be interpreted biologically and provide reasonable predictive capacity may best be based on data from individuals grouped into seasonal selection strategies for particular geographical areas or similarities in topographical and vegetative associations. We used logistic regression, the information–theoretic approach, satellite imagery, and locational data (n = 31 females; 16 803 locations) from global positioning system (GPS) collared woodland caribou ( Rangifer tarandus caribou (Gmelin, 1788)) to model resource selection by animals during calving, summer, fall, breeding, winter, and late-winter seasons. Higher variation in resource use corresponded to times when caribou and their young were most susceptible to predation or when food resources were limited. Even with multiple selection strategies, caribou followed a general progression from higher to lower elevation habitats from calving and summer to late winter. Caribou selected against or completely avoided the burned–disturbed vegetation class in every season except summer. We incorporated RSFs with a raster geographic information system to create selection landscapes. We validated selection landscapes using withheld GPS data (n = 6077), 50 known calving sites, and Spearman’s rank correlation coefficient. Selection models and final selection landscapes performed well in validating use locations of woodland caribou in all seasons (all P < 0.003) and in predicting known calving sites (P < 0.001). When seasonal selection strategies are identified and models are coupled with validation, RSFs are effective tools to assist in conservation planning.


ARCTIC ◽  
2015 ◽  
Vol 68 (4) ◽  
pp. 472 ◽  
Author(s):  
Erica J. Newton ◽  
Kenneth F. Abraham ◽  
James A. Schaefer ◽  
Bruce A. Pond ◽  
Glen S. Brown ◽  
...  

Understanding the factors driving changes in species distributions is fundamental to conservation, but for wide-ranging species this is often complicated by the need for broad-scale observations across space and time. In the last three decades, the location of summer concentrations of migratory caribou (Rangifer tarandus) in southern Hudson Bay (SHB), Canada, has shifted south and east as much as 500 km. We used long-term data (1987 – 2011) to test two hypotheses that could explain the distribution shift: forage depletion and anthropogenic disturbance. Over time and space, we compared the body size of live-captured adult female caribou, dietary quality from fecal nitrogen in July, the location of VHF- and GPS-collared female caribou in July, distribution of all-terrain vehicle (ATV) tracks and caribou tracks in August, and the proximity of collared caribou to sections of the coast with higher ATV activity in spring and summer. The forage depletion hypothesis was supported by greater body size and dietary quality in caribou of the eastern portion of SHB than in western SHB animals in 2009 – 11. The anthropogenic disturbance hypothesis was supported by the negative correlation of the distributions of ATV tracks and caribou tracks on the coast in 2010 and the fact that caribou avoided areas with ATV activity by 10 – 14 km. In 1987, collared caribou were observed largely along the coast in western SHB in mid-July, while in 2009 – 11, they were inland in western SHB and along the coast in eastern SHB. While these locations demonstrate a substantial change in summer distri­bution over three decades, we were unable to differentiate between forage depletion and anthropogenic disturbance as a single causal factor of the distribution shift.


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