Northern Caribou Research Articles

Northern boreal caribou conservation should focus on anthropogenic disturbance, not disturbance-mediated apparent competition

Understanding the relative importance of threats to species across their range is critical for large-scale conservation planning. Scaling-up localized research to inform the Canada-wide boreal caribou (Rangifer tarandus caribou) recovery strategy epitomizes the challenge. Current policy draws heavily from data obtained at the southern front of range retraction. Here, disturbances benefiting early successional herbivores (e.g., moose [Alces alces]), and hence wolves (Canis lupus) imparts increased predation risk to caribou (via “disturbance-mediated apparent competition” [DMAC]). Anthropogenic linear features (e.g., corridors, roads etc.; LFs) also improve wolf hunting efficiency, exacerbating DMAC, with caribou thereby losing functional habitat. However, ~2/3 of extant caribou range occurs in northern Canadian Shield and Taiga habitat, which contrasts with southern areas in both disturbance regime (fire-dominated) and community assembly (e.g., no deer [Odocoileus spp.]). To test predictions of DMAC and LF-avoidance in a northern caribou population (Saskatchewan Boreal Shield; ~3% of habitat within 500 m of anthropogenic disturbance), we tracked 94 GPS-collared females (2014–2018). Unexpectedly, caribou did not avoid LFs at most scales of observation. Although they responded to vegetation in line with apparent competition, resiliency of conifer-dominated successional trajectories and muted moose-wolf responses to disturbance suggest that poor primary productivity may modulate the strength of DMAC to caribou—including its potential interaction with LFs to influence movements. Before focusing on DMAC as the principal threat to caribou in northern ecoregions, further studies investigating if caribou and predators functionally respond to increasing LF-availability are needed, as it may be most critical for conserving crucial source populations.

Caribou (Rangifer tarandus) and Inuit Nutrition Security in Canada.

Caribou (Rangifer tarandus) has been fundamental to the diet and culture of Arctic Indigenous Peoples for thousands of years. Although caribou populations observe natural cycles of abundance and scarcity, several caribou herds across the Circumpolar North have experienced dramatic declines in recent decades due to a range of interrelated factors. Broadly, the objectives of this study are to examine food and nutrition security in relation to wildlife population and management status across Inuit Nunangat (the Inuit homeland, consisting of four regions across the Canadian Arctic). Specifically, we: (1) characterize the contribution of caribou to Inuit nutrition across northern Canada and (2) evaluate the population and management status of caribou herds/populations harvested by Inuit. Dietary data were derived from the 2007-2008 Inuit Health Survey, which included dietary information for Inuit adults (n = 2097) residing in thirty-six communities, spanning three regions (the Inuvialuit Settlement Region, Nunavut, and Nunatsiavut) of the Canadian North. Published information regarding the range, abundance, status, and management status of caribou herds/populations was collected through document analysis and was validated through consultation with northern wildlife experts (territorial governments, co-management, and/or Inuit organizations). While caribou contributed modestly to total diet energy (3-11% of intake) across the regions, it was the primary source of iron (14-37%), zinc (18-41%), copper (12-39%), riboflavin (15-39%), and vitamin B12 (27-52%), as well as a top source of protein (13-35%). Restrictions on Inuit subsistence harvest (harvest quotas or bans) are currently enacted on at least six northern caribou herds/populations with potential consequences for country food access for over twenty-five Inuit communities across Canada. A holistic multi-sectorial approach is needed to ensure the sustainability of wildlife populations, while supporting Inuit food and nutrition security in the interim.

The temporal niche and seasonal differences in predation risk to translocated and resident woodland caribou (Rangifertaranduscaribou)

Mountain caribou are an endangered ecotype of woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) that continue to decline, ultimately, due to habitat loss and, proximately, due to predation. A particularly imperilled population of mountain caribou was experimentally augmented with 19 northern caribou, a geographically distinct ecotype, from northern British Columbia. We examined seasonal variation in risk of predation by cougars (Puma concolor (L., 1771)) to the translocated caribou with comparison to resident caribou. Our basic approach followed the Movement Ecology Paradigm, in particular the interplay among why move, and when and where to move. We applied a cluster analysis framework on space-use patterns of GPS radio-collared animals to determine biologically relevant seasons. Then we examined the spatiotemporal similarity in habitat use between caribou groups and cougars across these seasons. This analysis included a control group of caribou from the donor herd that were not translocated. Five resident caribou seasons, two donor caribou seasons, and two cougar seasons were identified. Resident caribou remained at high elevations year-round and primarily selected habitats not used by cougars. In contrast, translocated caribou tended to occupy low-elevation habitats extensively used by cougars, resulting in predation of eight translocated caribou, six of which were by cougars. We concluded that the translocated caribou did not adopt the predator avoidance strategies of resident caribou, rendering them more vulnerable to predation. We make recommendations for future herd augmentations, notably that donor caribou should be of the same ecotype, have similar seasonal patterns of habitat use and associated behavioural repertoires, and be exposed to the same complex of predators.

Woodland Caribou Alpine Range Restoration: An Application for Lichen Transplants

Woodland caribou, a Schedule 1 ‘threatened’ species under the Canadian Federal Species at Risk Act, use alpine ecosystems in the mountainous South Peace region of British Columbia for core winter habitat, in part because they are able to crater for terrestrial lichen beneath the relatively thin snow pack on the windswept mountain peaks. A number of proposed and operating open pit coal mine developments will create disturbances within these alpine ecosystems. An Implementation Plan for the Ongoing Management of the South Peace Northern Caribou has been created by the province of B.C. to direct actions for South Peace region caribou population recovery, and part of the Mitigation and Monitoring Plan that must be created for disturbances in caribou core habitat is a habitat restoration plan. A component of the alpine habitat that must be restored is terrestrial lichen that woodland caribou rely on for winter forage; however, published studies about the restoration of terrestrial lichens are scarce. The majority of studies obtainable were small-scale trials or exploratory studies in reindeer range in northern European boreal forest, or in forested and alpine ecosystems in B.C. This paper reviews the literature on the feasibility of transplanting terrestrial lichen, and interprets the results for application in alpine caribou habitat restoration. Three main areas where further research is required to develop reindeer lichen transplantation techniques are suggested: methods to promote lichen propagule retention on reclaimed sites; investigating sources and collection methods for lichen propagules; and techniques for storage of viable lichen propagules.

Silviculture Options for Use in Ranges Designated for the Conservation of Northern Caribou in British Columbia

This review and synthesis of silviculture strategies was conducted to clarify options for managing forest stands in areas designated for conservation of habitat for the northern ecotype of woodland caribou in British Columbia. Information about the ecology, distribution, population status, and legal management measures for herds of northern caribou provided the background for assessing risk to forestry operations. A review of current scientific research and operational trials was used to reveal potential impacts of forestry on caribou life requisites. Specific attention was paid to the implications of the recent mountain pine beetle infestation. General guidelines (desired conditions) are provided for operating in areas designated for the conservation of caribou.

Application of a molecular tool to describe the diversity and distribution of gastro-intestinal parasites in northern caribou

Climate change is driving a northward shift in the distribution of North American wildlife, including ungulates. Temperate ungulates are host to a diversity of gastrointestinal nematode species, many of which are not found in wood¬ land and barren-ground caribou (Rangifer tarandus). Some of the most pathogenic of these parasites are those of the family Trichostrongylidae which are known to induce considerable morbidity and mortality in livestock globally. Although invasion of new trichostrongylid species to high latitudes may have significant impact on the health of naive (unexposed) caribou populations, the northern diversity and distribution of most species is unknown. In fact, our recent trichostrongylid survey of 20 wild ungulates in central Alberta and Saskatchewan revealed four new host and seven new geographic records. A challenge to determining parasite diversity is that many trichostrongyid eggs are morphologically indistin¬ guishable and post-mortem recovery and examination of adult nematodes is necessary to establish species identification. To better describe the diversity of parasite fauna that may infect northern caribou, we have developed a rapid, non-invasive tool, Single Stranded Conformation Polymorphism (SSCP), for broad-scale screening of cervid fecal pellets for trichostrongylid parasites. SSCP is a simple PCR-based technique that allows for species-specific electrophoretic discrimination using ITS-2 rDNA from parasite eggs. Trichostrongylid eggs in fecal pellets from three ecotypes of caribou, white-tailed deer (Odocoileus virginianus), mule deer (O. hemionus) and elk (Cervus elaphus) are being screened using SSCP to determine parasite diversity and range along two north-south transects in western Canada. Results outlining trichostrongylid diver¬ sity and distribution and implications for threatened woodland and barren-ground caribou populations will be reported. Baseline data on parasite biodiversity and distribution will provide a platform from which managers and veterinarians can monitor parasite range expansion in a warming climate and identify key parasite related risks.

Natural regeneration of lodgepole pine following partial harvesting on northern caribou winter range in west-central British Columbia

This study compares pine natural regeneration density and height growth in small harvested openings (0.01–0.07 ha) within two biogeoclimatic subzones (Sub-Boreal Pine–Spruce [SBPS] xc and Montane Spruce [MS] xv) and three partial harvesting treatments on northern caribou (Rangifer tarandus caribou Gmelin) winter range in the western Chilcotin region of British Columbia, Canada. Regeneration density was assessed annually for 7 years (1996–2002). In year 7, post-logging ingress stems > 1 year old had a significantly greater density on SBPSxc blocks (5898 stems per hectare) than on the higher-elevation MSxv blocks (1829 stems per hectare). The percentage of 2-m2 plots with a natural post-logging seedling > 1 year old averaged 52% in the SBPSxc and 31% in the MSxv. Advance regeneration added substantially to density and stocking in the SBPSxc but not in the MSxv. These results indicate that small (0.01–0.07 ha) harvested openings in the SBPSxc can be naturally restocked by lodgepole pine without post-logging site preparation, but higher-elevation blocks in the MSxv will need to be planted to ensure full stocking by lodgepole pine within 7 years. However, the long period between harvest entries on caribou winter range may still allow sufficient time to naturally regenerate openings in the MSxv.

Forest bird response to partial cutting in lodgepole pine forests on caribou winter range in west-central British Columbia

Breeding birds were surveyed 1 year pre-harvest (1995) and 4 years post-harvest (1996–2001) to measure the response to partial cutting in old lodgepole pine (Pinus contorta Dougl.) forests on the Chilcotin Plateau of British Columbia. The irregular group shelterwood and group selection systems recommended to manage northern caribou (Rangifer tarandus caribou Gmelin) habitat did not negatively affect the breeding bird community. In some years within the post-harvest period, dark-eyed juncos (Junco hyemalis L.), red crossbills (Loxia curvirostra L.), yellow-rumped warblers (Dendroica coronata L.), and gray jays (Perisoreus canadensis L.) showed significant (α = 0.05) increases in use of the partial-cutting treatments compared with the no-harvest treatment. No species decreased significantly in any of the partial-cutting treatments. The increased observations of mostly common species resulted in significantly (α = 0.05) higher species richness, and increased frequency of observations for the bird community in some years in the partial cuts. Partial cutting of caribou habitat will maintain bird communities typical of mature to older lodgepole pine forests.

Seedling response following partial cutting in lodgepole pine forests on caribou winter range in west-central British Columbia

Group selection and irregular group shelterwood silvicultural systems were applied to older lodgepole pine (Pinus contorta var. latifolia) forests in west-central British Columbia to determine their potential for maintaining northern caribou (Rangifer tarandus caribou) habitat. These silvicultural systems created small openings 15–30 m wide,which were planted with lodgepole pine and interior spruce (Picea glauca x Picea engelmannii) seedlings. Fifth-year survival and growth results indicate that either species could adequately regenerate the small openings created by partial cutting. Pine survival in the partial cuts (93–95%) was comparable to the clearcuts (94%). Pine height and height growth did not vary significantly between treatments; however, diameters were significantly larger in the clearcuts. After five years across all treatments, pine seedlings were 38–42 cm tall with diameters ranging from 7–11 mm. Spruce survival varied considerably between the clearcuts (35–98%) but was more consistent in the partial cuts (66–97%). Total height and height growth differed significantly among treatments, with the shortest spruce seedlings found in the clearcuts. Seedling diameter did not differ among treatments. Average fifth-year height ranged from 31 cm to 44 cm and diameters ranged from 7 mm to 9 mm. To maintain caribou habitat, species should be planted in similar proportions to the pre-harvest stand composition to avoid potential impacts on the terrestrial and arboreal lichens, which are important caribou forage. Key words: caribou, lodgepole pine, partial cutting, planted seedlings, interior spruce, group selection, irregular group shelterwood

Recent changes in seasonal variations of climate within the range of northern caribou populations

The Arctic is one region where it is expected that the impacts of a globally changing climate will be readily observed. We present results that indicate that climate derivatives of potential significance to caribou changed during the past 50 years. Many temperature derivatives reflect the increasing overall temperature in the Arctic such as decreases in the number of days with low temperatures, increases in the number of days with thaw, and days with extremely warm temperatures. Other derivatives reflect changes in the precipitation regime such as days with heavy precipitation and number of days when rain fell on snow. Our results indicate that specific caribou herds from across the Arctic were subjected to different variations of these derivatives in different seasons in the recent past. Examination of temperature and precipitation at finer time-steps than annual or monthly means, shows that climatic variations in the region are neither consistent through the seasons nor across space. Decadal changes in seasonal patterns of temperature and precipitation are shown for selected herds. A process for assessing caribou-focused climate derivatives is proposed.

Landscaping Desire

There is a long tradition in the Canadian North of outsiders imagining the region in accordance with their own cultural assumptions. At the turn of the century, naturalists, hunters, and explorers such as Ernest Thompson Seton, Caspar Whitney, and G. H. Blanchet began to describe the North as a last wilderness frontier that was teeming with vast herds of caribou. Many of their narratives also described native hunters as “wanton” killers of wildlife who threatened the sanctity of the Northern wilderness; they argued for increased government legislative controls and, paradoxically, the controlled exploitation of caribou in ranches or organized hunts. This article argues that all of these images of the Northern caribou had a profound influence on the federal government's wildlife policy in the region through the early part of the 20th century. Indeed, the federal government's restriction of native hunting rights through legislative reform and their tentative efforts to establish reindeer and caribou ranches can be traced directly to the cultural representations of the Northern landscape that appeared in the earliest natural history surveys of the Canadian North.

Habitat use by woodland caribou near Takla Lake in central British Columbia

Caribou (Rangifer tarandus) living in the mountainous areas of British Columbia are usually classified as either northern caribou, which spend much of the winter in low-elevation relatively young forests foraging primarily on terrestrial lichens, or mountain caribou, which winter in high-elevation old subalpine forests foraging exclusively on arboreal lichens. The forest-management practices necessary to conserve caribou differ substantially between these two categories of animals with different life-history strategies. Because of this variability in winter-habitat use, information relating specifically to Takla Lake caribou was required for forest management. To provide this information, we radio-collared 15 female caribou in two subherds in the vicinity of Takla Lake and determined their distribution and movements between January 1996 and May 1998 in relation to topography and vegetation cover. Habitat selection was examined using a classified satellite image. At the landscape scale, Takla Lake caribou avoided low-elevation forests (presumably because of the associated high risk of predation from wolves (Canis lupus)), occupying small seasonally overlapping home ranges (mean 151 km2) at intermediate and high elevations. Within home ranges in all seasons, caribou were most often found in the forest but, relative to availability, they selected forests only during calving. When in the forest, caribou selected open hybrid white-Engelmann spruce (Picea glauca × Picea engelmannii) - subalpine fir (Abies lasiocarpa) forests over lodgepole pine (Pinus contorta) and deciduous forests in all seasons except spring. Caribou selected open spruce-fir stands over dry and closed spruce-fir stands in all seasons except calving. We conclude that caribou feed primarily on arboreal lichens in winter, because the open spruce-fir forests that they use have moderate to high arboreal lichen abundance, deep snow, and few terrestrial lichens. Takla Lake caribou were not typical of either mountain or northern caribou, but as is typical of insular populations of any species, have adapted to the food, topography, and cover types available to them on their mountain islands in a sea of moose (Alces alces) and wolves.

Habitat use by woodland caribou near Takla Lake in central British Columbia

Caribou (Rangifer tarandus) living in the mountainous areas of British Columbia are usually classified as either northern caribou, which spend much of the winter in low-elevation relatively young forests foraging primarily on terrestrial lichens, or mountain caribou, which winter in high-elevation old subalpine forests foraging exclusively on arboreal lichens. The forest-management practices necessary to conserve caribou differ substantially between these two categories of animals with different life-history strategies. Because of this variability in winter-habitat use, information relating specifically to Takla Lake caribou was required for forest management. To provide this information, we radio-collared 15 female caribou in two subherds in the vicinity of Takla Lake and determined their distribution and movements between January 1996 and May 1998 in relation to topography and vegetation cover. Habitat selection was examined using a classified satellite image. At the landscape scale, Takla Lake caribou ...

A Method for Estimating Caribou Consumption by Northern Canadians

Caribou is an important source of protein in the diet of northern Canadians. It is also an important pathway for airborne environmental contaminants that concentrate in the lichen - caribou - human food chain. We present a method for estimating caribou consumption that is independent of questionnaires and dietary surveys. The method is based on direct, whole-body measurements of fallout radiocesium in northern caribou consumers and on measurements of the concentrations of radiocesium in the meat. From the 1989-90 surveys of five Arctic communities, we obtained the following mean (90th percentile) intakes of caribou meat in grams per day: Baker Lake - males 65 (141), females 41 (88); Rae-Edzo - males 42 (103), females 31 (80); Old Crow - males 41 (108), females 23 (59); Fort McPherson - males 41 (77), females 32 (68); Aklavik - males 20 (47), females 15 (37). Compared with surveys carried out in the late 1960s, these values indicate a twofold to fourfold decrease in caribou consumption over a period of 20 years. A dietary survey questionnaire administered during the 1989-90 survey provided useful information on the consumption of various caribou organs, methods of meat preparation, and consumption of other traditional foods.

Caribou in British Columbia: A 1996 status report

Caribou (Rangifer tarandus) in British Columbia are classified into mountain, northern and boreal ecotypes based on behavioural and ecological characteristics. We recognized 12 mountain caribou herds, 27 northern caribou herds, and an area occupied by low density boreal caribou dispersed in the boreal forests of the northeast portion of the province. Abundance estimates were usually based on attempts at total counts made from the air. Trends were based on repeated population estimates or the difference between recruitment and mortality rates for each herd. In 1996 there were approximately 18 000 caribou in British Columbia; 2300 mountain and 15 600 northern and boreal. These estimates suggest a slight increase in the numbers of both ecotypes over the last 18 years. Fifteen percent of the herds were reportedly increasing, 10% were decreasing, 31% were stable, but for 44% of the herds the trend was unknown. Historically caribou were found throughout 8 of the 14 biogeoclimatic zones in B.C. Caribou are now rarely found in the Sub-Boreal Spruce zone, likely due to increased predation from wolves that increased in response to increasing moose numbers. Ranges of several herds in the Engelmann Spruce — Subalpine Fir and Alpine Tundra zones of south-eastern British Columbia are also reduced relative to historic conditions, probably because of habitat loss, habitat fragmentation, predation and hunting. Forest harvesting represents the greatest threat to caribou habitat and current research focuses on the mitigation of forest harvesting impacts.

Ecosystem management and the conservation of caribou habitat in British Columbia

Woodland caribou (Rangifer tarandus caribou) in British Columbia inhabit a wide variety of forest ecosystems. Numerous research projects have provided information that has been used to develop caribou habitat management recommendations for different areas. Recently, the province has implemented guidelines to protect biodiversity that are based on an ecosystem management strategy of mimicking natural forest conditions. There is a great deal of similarity between caribou management recommendations and biodiversity recommendations within different forest types. In mountain caribou habitat, both approaches recommend maintaining a landscape dominated by old and mature forests, uneven-aged management, small cutblocks, and maintaining mature forest connectivity. In northern caribou habitat, both approaches recommend maintaining some older stands on the landscape (but less than for mountain caribou), even-aged management, and a mosaic of large harvest units and leave areas. The ecosystem management recommendations provide a useful foundation for caribou habitat conservation. More detailed information on caribou and other management objectives can then be used to fine-tune those recommendations.

Forestry and caribou in British Columbia

Forest harvesting in mountain caribou range has been an issue for many years. Radiotelemetry studies on mountain caribou in the last decade have helped identify the geographic areas of conflict, improved understanding of the mechanisms by which forestry activities affect caribou, and suggested new approaches to management. Forest harvesting has begun to impact population of northern caribou, and researchers have begun to examine those impacts. Interest in integrating forest management and caribou habitat management has increased and has manifested itself in two ways: experimentation with special stand management practices intended to maintain or create caribou habitat, and the creation of tools to help managers make decisions in a landscape context.