Early-winter diet of woodland caribou in relation to snow accumulation, Selkirk Mountains, British Columbia, Canada

1990 ◽  
Vol 68 (12) ◽  
pp. 2691-2694 ◽  
Author(s):  
Eric M. Rominger ◽  
John L. Oldemeyer
Keyword(s):  
British Columbia ◽  
Rangifer Tarandus ◽  
Transition Period ◽  
Management Strategies ◽  
Snow Accumulation ◽  
Late Winter ◽  
Early Winter ◽  
Accumulation Rates ◽  
Woodland Caribou ◽  
Selkirk Mountains

Woodland caribou (Rangifer tarandus caribou) in the southern Selkirk Mountains of British Columbia shift from a diet of primarily vascular taxa during snow-free months to an arboreal lichen – conifer diet during late winter. We present evidence that caribou diets, during the early-winter transition period, are influenced by snow accumulation rates. Caribou shift to an arboreal lichen – conifer diet earlier during winters of rapid snow accumulation and forage extensively on myrtle boxwood (Pachistima myrsinites), an evergreen shrub, and other vascular plants during years of slower snow accumulation. The role of coniferous forage in early-winter food habits is examined. Forest management strategies can be developed to provide habitat that will enable caribou to forage in response to varying snow accumulation rates.

scholarly journals Factors influencing variation in site fidelity of woodland caribou (Rangifer tarandus caribou) in southeastern British Columbia

2020 ◽  
Author(s):  
Heiko Wittmer ◽  
B McLellan ◽  
F Hovey
Keyword(s):  
British Columbia ◽  
Site Fidelity ◽  
Rangifer Tarandus ◽  
Snow Accumulation ◽  
Limiting Factors ◽  
Late Winter ◽  
Behavioural Plasticity ◽  
Rangifer Tarandus Caribou ◽  
Early Winter ◽  
Woodland Caribou

Where predation is a major limiting factor, it has been postulated that woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) reduce movements to minimize contact with predators and exhibit fidelity to seasonal ranges. We examined fidelity behaviour within season and among years of woodland caribou based on locations of 65 radio-collared individuals in British Columbia, Canada. We used average linear distances between all possible pairs of radiolocations of individuals to assess fidelity. Among-year interlocation distances were similar to within-season interlocation distances during summer, indicating that caribou did not shift their distribution during seasons when they were most vulnerable to predation. Among-year interlocation distances were significantly greater than within-season interlocation distances during both early winter and late winter, indicating that individual caribou shifted their distribution among winters. The amount that an individual's distribution shifted among winters varied among and within individuals over different years. During early winter this behavioural plasticity was correlated with snow accumulation, with individuals having greater interlocation distances in years with high snow accumulation. Our results indicate that site fidelity outside the calving season is unlikely solely influenced by predator avoidance. We suggest that seasonal shifts in the importance of limiting factors vary from predation in summer to food in winter. © 2006 NRC.

scholarly journals Factors influencing variation in site fidelity of woodland caribou (Rangifer tarandus caribou) in southeastern British Columbia

2006 ◽  
Vol 84 (4) ◽  
pp. 537-545 ◽  
Author(s):  
Heiko U. Wittmer ◽  
Bruce N. McLellan ◽  
Frederick W. Hovey
Keyword(s):  
British Columbia ◽  
Site Fidelity ◽  
Rangifer Tarandus ◽  
Snow Accumulation ◽  
Limiting Factors ◽  
Late Winter ◽  
Behavioural Plasticity ◽  
Rangifer Tarandus Caribou ◽  
Early Winter ◽  
Woodland Caribou

Where predation is a major limiting factor, it has been postulated that woodland caribou ( Rangifer tarandus caribou (Gmelin, 1788)) reduce movements to minimize contact with predators and exhibit fidelity to seasonal ranges. We examined fidelity behaviour within season and among years of woodland caribou based on locations of 65 radio-collared individuals in British Columbia, Canada. We used average linear distances between all possible pairs of radiolocations of individuals to assess fidelity. Among-year interlocation distances were similar to within-season interlocation distances during summer, indicating that caribou did not shift their distribution during seasons when they were most vulnerable to predation. Among-year interlocation distances were significantly greater than within-season interlocation distances during both early winter and late winter, indicating that individual caribou shifted their distribution among winters. The amount that an individual’s distribution shifted among winters varied among and within individuals over different years. During early winter this behavioural plasticity was correlated with snow accumulation, with individuals having greater interlocation distances in years with high snow accumulation. Our results indicate that site fidelity outside the calving season is unlikely solely influenced by predator avoidance. We suggest that seasonal shifts in the importance of limiting factors vary from predation in summer to food in winter.

scholarly journals Factors influencing variation in site fidelity of woodland caribou (Rangifer tarandus caribou) in southeastern British Columbia

2020 ◽  
Author(s):  
Heiko Wittmer ◽  
B McLellan ◽  
F Hovey
Keyword(s):  
British Columbia ◽  
Site Fidelity ◽  
Rangifer Tarandus ◽  
Snow Accumulation ◽  
Limiting Factors ◽  
Late Winter ◽  
Behavioural Plasticity ◽  
Rangifer Tarandus Caribou ◽  
Early Winter ◽  
Woodland Caribou

Where predation is a major limiting factor, it has been postulated that woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) reduce movements to minimize contact with predators and exhibit fidelity to seasonal ranges. We examined fidelity behaviour within season and among years of woodland caribou based on locations of 65 radio-collared individuals in British Columbia, Canada. We used average linear distances between all possible pairs of radiolocations of individuals to assess fidelity. Among-year interlocation distances were similar to within-season interlocation distances during summer, indicating that caribou did not shift their distribution during seasons when they were most vulnerable to predation. Among-year interlocation distances were significantly greater than within-season interlocation distances during both early winter and late winter, indicating that individual caribou shifted their distribution among winters. The amount that an individual's distribution shifted among winters varied among and within individuals over different years. During early winter this behavioural plasticity was correlated with snow accumulation, with individuals having greater interlocation distances in years with high snow accumulation. Our results indicate that site fidelity outside the calving season is unlikely solely influenced by predator avoidance. We suggest that seasonal shifts in the importance of limiting factors vary from predation in summer to food in winter. © 2006 NRC.

scholarly journals Comparison of seasonal habitat selection between threatened woodland caribou ecotypes in central British Columbia

Rangifer ◽  
2007 ◽  
Vol 27 (4) ◽  
pp. 111 ◽  
Author(s):  
Elena S. Jones ◽  
Michael P. Gillingham ◽  
Dale R. Seip ◽  
Douglas C. Heard
Keyword(s):  
British Columbia ◽  
Habitat Use ◽  
Rocky Mountains ◽  
Vegetation Cover ◽  
Rangifer Tarandus ◽  
Late Winter ◽  
Woodland Caribou ◽  
Recovery Planning ◽  
Specific Mapping ◽  
Selection Of

Woodland caribou (Rangifer tarandus caribou) in British Columbia have been classified into ecotypes based on differences in use of habitat in winter. Although recovery planning focuses on ecotypes, habitat use and selection varies within ecotypes. Our objectives were to compare habitat use and selection among previously identified woodland caribou herds at the transition zone between northern (Moberly, Quintette, and Kennedy herds) and mountain (Parsnip herd) ecotypes in central British Columbia. We developed selection models for each herd in spring, calving, summer/fall, early and late winter. Topographic models best predicted selection by most herds in most seasons, but importance of vegetation-cover was highlighted by disproportionate use of specific vegetation-cover types by all caribou herds (e.g., in early winter, 75% of Kennedy locations were in pine-leading stands, 84% of Parsnip locations were in fir and fir-leading stands, and 87 and 96% of locations were in alpine for the Moberly and Quintette herds, respectively). Using a combination of GPS and VHF radio-collar locations, we documented some spatial overlap among herds within the year, but use of vegetation-cover types and selection of elevations, aspects, and vegetation-cover types differed among herds and within ecotypes in all seasons. Habitat use and selection were most similar between the two northern-ecotype herds residing on the eastern side of the Rocky Mountains. This research indicates that habitat use and selection by caribou herds in all seasons is more variable than ecotype classifications suggest and demonstrates the value of undertaking herd-specific mapping of critical habitat for woodland caribou.

scholarly journals Characteristics of Early-Winter Caribou, Rangifer tarandus caribou, Feeding Sites in the Southern Purcell Mountains, British Columbia

2003 ◽  
Vol 117 (3) ◽  
pp. 352 ◽  
Author(s):  
Trevor A. Kinley ◽  
John Bergenske ◽  
Julie-Anne Davies ◽  
David Quinn
Keyword(s):  
British Columbia ◽  
Rangifer Tarandus ◽  
Winter Season ◽  
Subalpine Forest ◽  
Winter Period ◽  
Late Winter ◽  
Abies Lasiocarpa ◽  
Rangifer Tarandus Caribou ◽  
Early Winter ◽  
Winter Habitat

Mountain Caribou are a rare ecotype of Woodland Caribou (Rangifer tarandus caribou) inhabiting the high-snowfall region of southeastern British Columbia, and are defined by their late-winter reliance on arboreal hair lichen of the genus Bryoria. During early winter, there is considerable variation in habitat use among populations. We snow-trailed Caribou in the southern Purcell Mountains during early winter to determine foraging patterns for the Purcell population. When snow was ≤51 cm deep, Caribou fed on Grouseberry (Vaccinium scoparium), the terrestrial lichen Cladonia, and arboreal lichens of the genus Bryoria. When snow was ≥62 cm deep, they ate exclusively arboreal lichens. In both periods, Caribou ate arboreal lichen from essentially every downed tree or branch encountered and fed with a higher intensity at downed trees than standing trees. During the low-snow period, Caribou fed at fewer trees but used those with greater lichen abundance, and fed more intensively at each, compared to the deep-snow period. In comparison to trees occurring on the foraging path but at which Caribou did not feed, those from which arboreal lichen was foraged intensively were of larger diameter, had greater lichen abundance, and were more likely to be Subalpine Fir (Abies lasiocarpa) or Engelmann Spruce (Picea engelmannii) and less likely to be Whitebark Pine (Pinus albicaulis), Lodgepole Pine (P. contorta) or Alpine Larch (Larix lyalli). The shift in diet between the low-snow and deep-snow periods reflected two modes of foraging within the early winter period, distinct from one another and apparently also distinct from the late-winter season. Management for early-winter habitat will require retention of some commercially significant forest across extensive areas, both near the subalpine forest – subalpine parkland ecotone and lower in the subalpine forest.

scholarly journals A synthesis of scale-dependent ecology of the endangered mountain caribou in British Columbia, Canada

Rangifer ◽  
2008 ◽  
Vol 28 (1) ◽  
pp. 33
Author(s):  
Robert Serrouya ◽  
Bruce N. McLellan ◽  
Clayton D. Apps ◽  
Heiko U. Wittmer
Keyword(s):  
British Columbia ◽  
Rangifer Tarandus ◽  
Spatial Scales ◽  
Management Strategies ◽  
Population Level ◽  
Limiting Factors ◽  
Conservation Strategies ◽  
Integrative Approach ◽  
Rangifer Tarandus Caribou ◽  
Multi Scale

Mountain caribou are an endangered ecotype of woodland caribou (Rangifer tarandus caribou) that live in highprecipitation, mountainous ecosystems of southeastern British Columbia and northern Idaho. The distribution and abundance of these caribou have declined dramatically from historical figures. Results from many studies have indicated that mountain caribou rely on old conifer forests for several life-history requirements including an abundance of their primary winter food, arboreal lichen, and a scarcity of other ungulates and their predators. These old forests often have high timber value, and understanding mountain caribou ecology at a variety of spatial scales is thus required to develop effective conservation strategies. Here we summarize results of studies conducted at three different spatial scales ranging from broad limiting factors at the population level to studies describing the selection of feeding sites within seasonal home ranges of individuals. The goal of this multi-scale review is to provide a more complete picture of caribou ecology and to determine possible shifts in limiting factors across scales. Our review produced two important results. First, mountain caribou select old forests and old trees at all spatial scales, signifying their importance for foraging opportunities as well as conditions required to avoid alternate ungulates and their predators. Second, relationships differ across scales. For example, landscapes dominated by roads and edges negatively affect caribou survival, but appear to attract caribou during certain times of the year. This juxtaposition of fine-scale behaviour with broad-scale vulnerability to predation could only be identified through integrated multi-scale analyses of resource selection. Consequently we suggest that effective management strategies for endangered species require an integrative approach across multiple spatial scales to avoid a focus that may be too narrow to maintain viable populations. Abstract in Norwegian / Sammendrag:Skala-avhengig økologi og truet fjellvillrein i Britisk ColumbiaFjellvillreinen i de nedbørsrike fjellområdene i sørøstre Britisk Columbia og nordlige Idaho som er en truet økotype av skogsreinen (Rangifer tarandus caribou), har blitt kraftig redusert både i utbredelse og antall. Mange studier har vist at denne økotypen er avhengig av vinterføden hengelav i gammel barskog hvor det også er få andre klovdyr og dermed få predatorer. Slik skog er også viktige hogstområder, og å forstå økologien til fjellvillreinen i forskjellige skaleringer er derfor nødvendig for å utvikle forvaltningsstrategier som kan berge og ta vare på denne reinen. Artikkelen gir en oversikt over slike arbeider: fra studier av begrensende faktorer på populasjonsnivå til studier av sesongmessige beiteplasser på individnivå. Hensikten er å få frem et mer helhetlig perspektiv på fjellvillreinen og finne hvordan de begrensende faktorene varierer etter skaleringen som er benyttet i studiet. Oversikten vår frembragte to viktige resultater; 1) Uansett skalering så velger dyrene gammel skog og gamle trær. 2) Dyrenes bruk av et område kan variere med benyttet skalering, for eksempel vil landskap utbygd med veier og hogstflater være ufordelaktig for overlevelsen, men synes likevel å kunne tiltrekke fjellvillreinen til visse tider av året. Forholdet mellom atferd ut fra fin-skalering og stor-skalering sårbarhet hva gjelder predasjon, ville kun blitt avdekket ved flere-skaleringsanalyse av hvordan ressursene benyttes. Ut fra dette foreslår vi at forvaltningsstrategier for truete bestander som eksempelvis fjellvillreinen, må baseres på tilnærminger ut fra ulike skaleringer for å hindre at et for snevert perspektiv kan begrense muligheten for vedvarende levedyktighet.

Variation in the seasonal selection of resources by woodland caribou in northern British Columbia

2008 ◽  
Vol 86 (8) ◽  
pp. 812-825 ◽  
Author(s):  
D. D. Gustine ◽  
K. L. Parker
Keyword(s):  
Conservation Planning ◽  
Resource Selection ◽  
Rangifer Tarandus ◽  
Rank Correlation ◽  
Late Winter ◽  
Theoretic Approach ◽  
Woodland Caribou ◽  
Predictive Capacity ◽  
Spearman’S Rank Correlation ◽  
Selection Strategies

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.

scholarly journals Feeding site selection by woodland caribou in north-central British Columbia

Rangifer ◽  
2000 ◽  
Vol 20 (5) ◽  
pp. 158 ◽  
Author(s):  
Chris J. Johnson ◽  
Katherine L. Parker ◽  
Douglas C. Heard
Keyword(s):  
British Columbia ◽  
Rangifer Tarandus ◽  
Lower Percentage ◽  
Percent Cover ◽  
Woodland Caribou ◽  
North Central ◽  
Feeding Site ◽  
Feeding Sites ◽  
Cladina Rangiferina ◽  
The Individual

We examined the foraging habits of the northern woodland caribou ecotype {Rangifer tarandus caribou) at the scale of the individual feeding site. Field data were collected in north-central British Columbia over two winters (Dec 1996-Apr 1998). We trailed caribou and measured vegetation characteristics (species composition and percent cover), snow conditions (depth, density, and hardness), and canopy closure at terrestrial and arboreal feeding sites, and at random sites where feeding had not occurred. Logistic regression was used to determine the attributes of feeding sites that were important to predicting fine scale habitat selection in forested and alpine areas. In the forest, caribou selected feeding sites that had a greater percent cover of Cladina mitis and Cladonia spp, lower snow depths, and a lower percentage of debris and moss. Biomass of Bryoria spp. at the 1-2 m stratum above the snow significantly contributed to predicting what trees caribou chose as arboreal feeding sites. In the alpine, caribou selected feeding sites with a greater percent cover of Cladina mitis, Cladina rangiferina, Cetraria cucullata, Cetraria nivalis, Thamnolia spp., and Stereocaulon alpinum as well as lower snow depths.

scholarly journals Population dynamics of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou) in British Columbia, Canada

2020 ◽  
Author(s):  
Heiko Wittmer ◽  
BN McLellan ◽  
DR Seip ◽  
JA Young ◽  
TA Kinley ◽  
...  
Keyword(s):  
British Columbia ◽  
Population Dynamics ◽  
Rangifer Tarandus ◽  
Population Decline ◽  
Survival Rates ◽  
Adult Survival ◽  
Rangifer Tarandus Caribou ◽  
Vital Rates ◽  
Woodland Caribou ◽  
Annual Survival

We used census results and radiotelemetry locations of >380 collared individuals sampled over the entire distribution of the endangered mountain ecotype of woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) in British Columbia, Canada, to delineate population structure and document the size and trend of the identified populations. We also describe the spatial pattern of decline and the causes and timing of adult mortality and provide estimates of vital rates necessary to develop a population viability analysis. Our results indicate that the abundance of mountain caribou in British Columbia is declining. We found adult female annual survival rates below annual survival rates commonly reported for large ungulates. The major proximate cause of population decline appears to be predation on adult caribou. Spatial patterns of population dynamics revealed a continuous range contraction and an increasing fragmentation of mountain caribou into smaller, isolated subpopulations. The population fragmentation process predominantly occurs at the outer boundaries of the current distribution. Our results indicate that recovery strategies for mountain caribou should be directed at factors contributing to the fragmentation and isolation of mountain caribou populations as well as management strategies aimed at increasing adult survival. © 2005 NRC Canada.

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