Distribution Of Caribou Research Articles

Comparing landscape partitioning approaches to protect wildlife habitat in managed forests

Industrial forestry activities can increase landscape fragmentation, impacting wildlife populations, particularly Canada’s woodland caribou, Rangifer tarandus caribou. To protect caribou in areas with forestry activities, the province of Ontario, Canada, implemented a Dynamic Caribou Harvest Schedule (DCHS). The DCHS spatially aggregates harvest disturbance into regions and distributes them across the landscape to maintain forest patch size–age distributions consistent with a natural variation range. However, the DCHS may negatively impact the cost of timber supply. We compared the DCHS with an alternative zoning approach that assigned the harvest deferral and operational management zones within a large forest area. We compared these approaches using an optimization model that combined harvest scheduling, access road construction, and caribou protection sub-problems. We formulated the protection of caribou habitat and road construction as network flow problems, while the harvesting problem incorporated the ecological constraints prescribed by the forest management plan. We compared the DCHS and zoning approaches in the Wabadowgang Noopming Forest of Ontario, a boreal area within the caribou distribution zone. For the same volume of sustainable harvest, the zoning approach protected less total area but more habitat and old-growth stands over the long term, and yielded lower timber costs by 1.2–2.2 $·m−3 than the DCHS.

Protecting boreal caribou habitat can help conserve biodiversity and safeguard large quantities of soil carbon in Canada

Boreal caribou require large areas of undisturbed habitat for persistence. They are listed as threatened with the risk of extinction in Canada because of landscape changes induced by human activities and resource extraction. Here we ask: Can the protection of habitat for boreal caribou help Canada meet its commitments under the United Nations Convention on Biological Diversity and United Nations Framework Convention on Climate Change? We identified hotspots of high conservation value within the distribution of boreal caribou based on: (1) three measures of biodiversity for at risk species (species richness, unique species and taxonomic diversity); (2) climate refugia or areas forecasted to remain unchanged under climate change; and, (3) areas of high soil carbon that could add to Canada’s greenhouse gas emissions if released into the atmosphere. We evaluated the overlap among hotspot types and how well hotspots were represented in Canada’s protected and conserved areas network. While hotspots are widely distributed across the boreal caribou distribution, with nearly 80% of the area falling within at least one hotspot type, only 3% of the distribution overlaps three or more hotspots. Moreover, the protected and conserved areas network only captures about 10% of all hotspots within the boreal caribou distribution. While the protected and conserved areas network adequately represents hotspots with high numbers of at risk species, areas occupied by unique species, as well as the full spectrum of areas occupied by different taxa, are underrepresented. Climate refugia and soil carbon hotspots also occur at lower percentages than expected. These findings illustrate the potential co-benefits of habitat protection for caribou to biodiversity and ecosystem services and suggest caribou may be a good proxy for future protected areas planning and for developing effective conservation strategies in regional assessments.

Remote sensing, snow modelling, survey data and Indigenous Knowledge show how snow and sea-ice conditions affect Peary caribou (Rangifer tarandus pearyi) distribution and inter-island and island–mainland movements

Accelerated warming of the Arctic has reduced sea ice and has increased the occurrence of winter extreme events like rain-on-snow and storms that impact snow-cover densification, affecting Peary caribou (Rangifer tarandus pearyi) seasonal movements and grazing conditions. We used caribou movements between Banks, Melville and Victoria islands and mainland Canada, documented from Indigenous Knowledge, to assess whether spatiotemporal trends in sea-ice anomalies (1983–2019) can be used as an indicator of caribou movement. We used the SNOWPACK model to evaluate how foraging conditions (as indexed by simulated snow properties) contribute to the prediction of caribou presence. Our results suggest that changes in sea-ice anomalies over time have impacted caribou crossings between islands: caribou no longer use areas with less sea ice whilst they continue to use areas with more sea ice. Our model evaluation shows that, when the simulated snow conditions are paired with other environmental variables, the ability of models to predict Peary caribou occurrence on land was enhanced across Banks and Melville islands. Overall, the land models suggest that caribou are more likely to occupy areas with lower density of snow accumulation and a majority of forb tundra with dwarf shrubs for Banks Island and cryptogam tundra, rush and grass for the Melville Island Complex. Our results suggest that future work monitoring changes in sea-ice and snow conditions will be important for understanding the impact of climate change on the distribution of Peary caribou in the western Arctic.

The direct and habitat-mediated influence of climate on the biogeography of boreal caribou in Canada

Effective species conservation efforts require insight into whether a species’ extent of occurrence may shift due to changing climate, habitat loss, or both. The extent of occurrence of the threatened boreal population of woodland caribou (Rangifer tarandus caribou; caribou) has contracted due to environmental and anthropogenic disruption, with further contractions predicted as boreal habitat shifts with the changing climate. However, the direct and indirect climate drivers of caribou extent of occurrence have not been explicitly investigated. We estimated and compared the influence of climate and habitat drivers on the occurrence of caribou ranges across the Canadian boreal forest. We fit path models that estimated the direct effects of climate on caribou range occurrence and its indirect effect through climate's influence on caribou habitat (i.e., forest cover, presence of peatland, human disturbance and wildfire). Our analysis suggests that the distribution of caribou ranges is less sensitive to the direct effects of climate than to those of habitat and human disturbance. However, through its relationship to caribou habitat, climate exerts indirect influence over the distribution of caribou. As the climate changes, future distributions of caribou may be more heavily relegated to refuge habitats, particularly peatlands in the western boreal forest. Our biogeographical approach enables more informed decisions for large-scale caribou conservation efforts (e.g. establishment of protected areas, habitat restoration) that account for potential shifts in the distribution of caribou under changing environmental and climatic conditions.

A Caribou Decline Foreshadowed by Inuit in the Central Canadian Arctic: A Retrospective Analysis

The Dolphin and Union (DU) caribou herd (Rangifer tarandus groenlandicus x pearyi), locally referred to as Island caribou, is a unique and at-risk ecotype of caribou that ranges on Victoria Island and the adjacent mainland in the central Canadian Arctic. To facilitate the incorporation of traditional knowledge (TK) and better inform the required species recovery plan, we analyzed an archived set of TK interviews done in Ekaluktutiak and Kugluktuk, Nunavut, in 2003. The overarching theme throughout the interviews was that the DU caribou were dynamic, constantly adapting to the changing environment around them. Accounts provided previously unexplored connections between temporal and spatial trends in DU caribou distribution, population, ecology, and disease syndromes. Findings of fewer animals, range shift, and increased observations of disease in the late 1990s and early 2000s suggest that early signs of the declines that have resulted in the herd being reassessed as endangered today were already apparent to Kugluktukmiut in 2003. In contrast, Ekaluktutiakmiut were seeing a stable population. Shifts in caribou range and consequently harvesting ranges were described by both communities, but more evident in Kugluktuk. When combined, the differing accounts of the two communities provided a deeper understanding of caribou ecology and trends across seasons, years, and a broad spatial range. Community differences demonstrate the cruciality of considering unique place-based perspectives and the importance of mobilizing TK from communities and knowledge keepers throughout the caribou range for a herd-level understanding. This study highlights the importance of timely analyses and reporting on TK studies to ensure a nimble conservation response in a rapidly changing environment.

Evaluating the Fitness for Use of Citizen Science Data for Wildlife Monitoring

Contributory citizen science programs focused on ecological monitoring can produce fine-grained and expansive data sets across spatial and temporal scales. With this data collection potential, citizen scientists can significantly impact the ability to monitor ecological patterns. However, scientists still harbor skepticism about using citizen science data in their work, generally due to doubts about data quality. Numerous peer-reviewed articles have addressed data quality in citizen science. Yet, many of these methods are not useable by third-party scientists (scientists who are not directly involved in the citizen science program). In addition, these methods generally capture internal data quality rather than a dataset’s potential to be used for a specific purpose. Assessing data fitness for use represents a promising approach to evaluating data accuracy and quality for different applications and contexts. In this article, we employ a Spatial, Temporal, Aptness, and Application (STAAq) assessment approach to assess data fitness for use of citizen science datasets. We tested the STAAq assessment approach through a case study examining the distribution of caribou in Denali National Park and Preserve. Three different datasets were used in the test, Map of Life data (a global scale citizen science mobile application for recording species observations), Ride Observe and Record data (a program sponsored by the park staff where incentivized volunteers observe species in the park), and conventionally collected radio collar data. The STAAq assessment showed that the Map of Life and Ride Observe and Record program data are fit for monitoring caribou distribution in the park. This data fitness for use approach is a promising way to assess the external quality of a dataset and its fitness to address particular research or monitoring questions. This type of assessment may help citizen science skeptics see the value and potential of citizen science collected data and encourage the use of citizen science data by more scientists.

Caribou Distribution and Movements in a Northern Alaska Oilfield

ABSTRACTAs industrial development increases in the range of barren‐ground caribou (Rangifer tarandus granti) across the warming Arctic, the need to understand the responses of caribou to development and to assess the effectiveness of mitigation measures increase accordingly. The Central Arctic Herd (CAH) of caribou ranges across northern Alaska, USA, and the herd's summer range includes the Prudhoe Bay and Kuparuk oilfields, where the herd has been exposed to oil development for >4 decades. We used location data from global positioning system (GPS) radio‐collars deployed on female CAH caribou for 106 collar‐years, recording locations every 2 hours during 2008–2019, to examine caribou distribution and movements during 7 different seasons of the year in relation to infrastructure in the Kuparuk oilfield, which is characterized by more design improvements and mitigation measures than the older Prudhoe Bay oilfield. We examined movement metrics in terms of distance to gravel infrastructure (roads and pads) and time before and after movements across infrastructure (crossings). We also employed integrated step‐selection analysis to compare caribou movements with random movements. Caribou distribution was influenced by insect activity, distance to coast, landcover, and terrain ruggedness, and we found large seasonal differences in caribou responses to infrastructure. Consistent with previous research findings, avoidance of areas near roads and pads was strongest during the calving season and some caribou used roads and pads as insect‐relief habitat when oestrid flies (warble fly [Hypoderma tarandi] and nose bot fly [Cephenemyia trompe]) were active. Caribou moved through the Kuparuk oilfield repeatedly during summer, averaging >2 road or pad crossings a day when harassment by mosquitoes (Aedes [Ochlerotatus] spp.) and oestrid flies were the predominant factors influencing caribou movements. Caribou moved faster while crossing roads and pads but showed little pattern in speed or turn angle with distance to roads and pads. These results demonstrate that the effects of petroleum development on a caribou herd with long‐term exposure to industrial activity vary widely by season. Maternal caribou avoid active roads and pads during calving, but the incorporation of appropriate mitigation measures in oilfield design allows caribou to move through the Kuparuk oilfield during other snow‐free seasons. © 2020 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.

Aerial survey and telemetry data analysis of a peripheral caribou calving area in northwestern Alaska

With industrial development expanding in the Arctic, there is increasing interest in quantifying the impacts of development projects on barren ground caribou (Rangifer tarandus granti). The primary data source to assess caribou distribution and predict impacts in remote areas of Alaska has shifted in recent decades from aerial survey data to telemetry data, but these techniques have different strengths and weaknesses. The ranges of two caribou herds, the Western Arctic Herd and the Teshekpuk Herd, overlap in northwest Alaska between Wainwright and Atqasuk, Alaska. Based on long-term telemetry data sets, this region was thought to be outside of the core calving ranges of both herds. Calving has long been reported to occur in this general area, but early reports assumed caribou were from the Western Arctic Herd and only one systematic aerial survey of caribou density and distribution during calving has been conducted in this area in recent decades. Following interest in industrial development in this area, we conducted aerial strip-transect surveys during early to mid-June 2013–2015 to directly assess the density and distribution of caribou in the area and we used existing telemetry data to compare our results to the seasonal distribution of both herds. Total caribou densities varied between 0.36 and 1.06 caribou/km² among years, and calf densities varied 0.04 and 0.25 calves/km² among years. Contrary to assumptions by early researchers in the area, telemetry data indicated that caribou in this area during early to mid-June were from the Teshekpuk Herd. The use of telemetry data alone underestimated the importance of this area for calving, but the combination of aerial surveys and telemetry data provided complementary information on caribou use of this area showing the importance of collecting the appropriate types of data for assessing potential impacts of development on caribou.

Mechanisms influencing the winter distribution of wolverine Gulo gulo luscus in the southern Columbia Mountains, Canada

To better understand the mechanisms driving the distribution of a threatened carnivore, wolverine Gulo gulo, in the southern Columbia Mountains, we contrasted four hypotheses; climate, food, human disturbance and trapping harvest. We used non-invasive hair snagging methods to examine wolverine occupancy with respect to these factors, collectively and by sex, at a 5 km radius scale around sampling sites and at a larger 10 km radius to evaluate consistency over changes in scale. For all analyses our top models included food and human disturbance. Of the four food items examined; caribou Rangifer tarandus, mountain goat Oreamnos americanus, moose Alces alces and hoary marmot Marmota caligata, wolverine occurrence was most closely related to hoary marmot habitat. With regards to human disturbance, we documented a negative association with forestry road density and a positive association with protected areas. The importance of climate was low compared to the food and disturbance hypotheses. Somewhat surprisingly, recent harvest was positively associated with subsequent wolverine presence. Our top 10 km scale models were similar to the 5 km scale, but with a stronger positive link to caribou distribution. We show that marmot habitat is important to wolverine in winter and suggest that management actions for conservation prioritize factors related to female occurrence, as these were more clearly defined than male. We demonstrate that human disturbance is a major driver of wolverine distribution. Protected areas appear to be providing secure habitat, and reducing road density or mechanized use of roads in winter should be considered for species conservation. A positive spatial relationship with recent harvest, in the context of a heavily harvested population, suggests that harvest data alone may not be useful in detecting population declines.

Conservation through co-occurrence: Woodland caribou as a focal species for boreal biodiversity

Understanding how conservation of woodland caribou, an at-risk species for which large undisturbed areas are often proposed to maintain viable populations, can contribute to conservation of boreal biodiversity is an important consideration for an ecosystem warming at twice the global average and experiencing rapid resource development. We assess the focal or ‘umbrella’ value of the boreal population of woodland caribou for conservation of mammalian and avian richness (n = 432) in the boreal region of Canada by (i) evaluating co-occurrence of caribou distribution with that of boreal mammals (n = 102), birds (n = 330), at-risk mammals (n = 11) and at-risk birds (n = 47); and (ii) conducting systematic conservation planning using MARXAN software to identify minimum representative and complementary reserve networks, comprised of planning units deemed large enough (10,000 km2) for persistence of terrestrial wildlife, both at the extent of boreal caribou distribution and the entire boreal region. While boreal caribou overlap with the range of 90% of boreal birds and mammals, area-efficient networks representative of boreal diversity focus on species-rich areas south of caribou distribution and other areas that contain relatively small-ranged species. A similar pattern occurs when the MARXAN analysis focused only on caribou distribution, i.e. representative networks are preferentially located on southern herd ranges. However, this situation differs markedly to include large areas within the distribution of caribou if anthropogenic footprint on the landscape is considered as a constraint on reserve design. Efforts to sustain boreal caribou offer considerable opportunities to conserve diversity of co-occurring mammals and birds, including areas of the relatively more disturbed caribou southern ranges that have irreplaceable value in an efficient and representative pan-boreal network of reserves. The high focal value of boreal caribou for animal diversity should be considered when making decisions and policy choices about how to best allocate conservation efforts across its extensive distribution.

Post-fire dynamics of terrestrial lichens: Implications for the recovery of woodland caribou winter range

Forest fires are the most dominant natural disturbance process influencing the habitat and distribution of woodland caribou (Rangifer tarandus caribou) in winter. This is a function of terrestrial lichens, the primary winter forage of caribou, taking decades to recover following fire. Working across the range of the Klaza caribou herd in the west-central Yukon, Canada, we used statistical count models to evaluate variation in lichen volume and percent cover among burns of different age classes. Burns of the same age had considerable variation in lichen abundance. Forage lichens were more abundant in coniferous stands with greater canopy openness, tree height, and basal area. Although not a significant parameter in models of volume or percent cover of lichen, time since burn improved model performance. Relative to thresholds in the published literature, most stands had sufficient lichen at 50 years post fire to be considered winter range for caribou. The relationship between caribou and burned landscapes is complex suggesting that wildlife and forest managers should look beyond burn age when accounting for the effects of fire on the availability and quality of winter habitat for woodland caribou.

Distribution and abundance of muskoxen (Ovibos moschatus) and Peary caribou (Rangifer tarandus pearyi) on Graham, Buckingham, and southern Ellesmere islands, March 2015

We flew a survey of southern Ellesmere Island, Graham Island, and Buckingham Island in March 2015 to obtain estimates of abundance for muskoxen and Peary caribou. Generally, muskoxen were abundant north of the Sydkap Ice Cap along Baumann Fiord, north of Goose Fiord, west and north of Muskox Fiord, and on the coastal plains and river valleys east of Vendom Fiord. Although few, they were also present on Bjorne Peninsula and the south coast between the Sydkap Ice Cap and Jakeman Glacier. We observed a total of 1146 muskoxen. Calves (approximately 10-months old) made up 22% of the observed animals. The population estimate was 3200 ± 602 SE (standard error) muskoxen, the highest muskox population size ever estimated for southern Ellesmere, Graham and Buckingham islands. This could be because previous efforts typically surveyed only a portion of our area or focused elsewhere, or the results were provided only as minimum counts rather than estimates of abundance. Regardless, our results indicate that the muskox population has recovered from low levels in 2005 of 312-670 (95% confidence interval [CI]) individuals. Peary caribou abundance appears to be low. We only saw 38 Peary caribou during our 2015 survey. This confounds appraisal of possible abundance change since 2005, when 109-442 caribou (95% CI) were estimated to inhabit the same surveyed area. We estimated 183 ± 128 SE Peary caribou, and suggest that their numbers are likely stable at low density on southern Ellesmere Island.

Landscape attributes explain migratory caribou vulnerability to sport hunting

ABSTRACTHuman disturbances are increasing in Arctic regions and have been suggested as one of the main factors explaining caribou (Rangifer tarandus) decline. The cumulative effects of disturbances may negatively affect caribou habitat use, survival, and population dynamics. Thus, there is a need to evaluate the impact of various human disturbances, especially those that cause direct mortality (e.g., sport hunting). We evaluated the relative importance of caribou and hunter habitat selection and landscape characteristics on caribou vulnerability to sport hunting in northern Québec, Canada. We used resource selection functions to describe habitat selection of 223 caribou and 87 hunters. We then characterized >169,000 caribou harvest sites recorded over 17 years according to the relative probability of co‐occurrence of caribou and hunters, the relative probability of occurrence of hunters only, or the characteristics of the landscape (e.g., distance to human infrastructures, elevation, land cover type). Landscape characteristics better explained caribou vulnerability to sport hunting than habitat selection of caribou and hunters, or their co‐occurrence. Caribou were more vulnerable in proximity to hunting infrastructures (e.g., roads, outfitter camps) than elsewhere, but caribou strongly avoided roads. Caribou were also more vulnerable on frozen lakes than in other land cover types. Lakes were, however, avoided by caribou and not selected by hunters. Harvest was more likely in smoother terrain, even if caribou and hunters did not select for this characteristic. We demonstrated caribou were more vulnerable in areas with good accessibility (near roads) or where caribou were easily detectable (lakes, smoother terrain), which also represents areas that were either avoided or not selected by caribou or hunters. This discrepancy between harvest distribution and behaviors of caribou and hunters suggests that harvest may be an opportunistic event where visibility and accessibility increased chances of success for hunters. Managers could use this information to manipulate hunting success according to population estimates and harvest quota by establishing minimal distance to risky areas within which hunting would be prohibited. © 2016 The Wildlife Society.

Evaluating the influence of anthropogenic landscape change on wolf distribution: implications for woodland caribou

AbstractAcross much of the range of woodland caribou (Rangifer tarandus caribou), predator–prey dynamics have changed as a result of large‐scale industrial development. Land clearing and associated early‐successional forests have resulted in a greater density and distribution of moose (Alces alces), deer (Odocoileusspp.), and their associated predators. This process of apparent competition has resulted in increased predation on woodland caribou. We employed a combination of field and statistical methods to better understand the distribution and interactions of wolves (Canis lupus) and caribou across a region with high levels of industrial development. We used count models to investigate the frequency of wolf occurrence relative to landcover types, disturbance features, and caribou habitat. As predicted, the co‐occurrence between caribou and wolves was rare. Similarly, the remains of caribou were identified at a small proportion of the sites where wolves killed large prey. Caribou occurred at low densities across the study area, and thus, wolves likely pursued other more abundant deer species. Encounters between wolves and caribou habitat was most likely to occur in the low‐elevation boreal forest and areas closer to and with higher densities of forestry cutblocks. Our results highlight the importance of understanding the spatial dynamics of multi‐species interactions when developing recovery strategies for threatened and endangered species.

Heading for the hills? Evaluating spatial distribution of woodland caribou in response to a growing anthropogenic disturbance footprint.

Anthropogenic landscape change (i.e., disturbance) is recognized as an important factor in the decline and extirpation of wildlife populations. Understanding and monitoring the relationship between wildlife distribution and disturbance is necessary for effective conservation planning. Many studies consider disturbance as a covariate explaining wildlife behavior. However, we propose that there are several advantages to considering the spatial relationship between disturbance and wildlife directly using utilization distributions (UDs), including objective assessment of the spatially explicit overlap between wildlife and disturbance, and the ability to track trends in this relationship over time. Here, we examined how central mountain woodland caribou (Rangifer tarandus caribou) distribution changed over time in relation to (i) anthropogenic disturbance, baseline range (defined using telemetry data from 1998 to 2005), and alpine habitat; and (ii) interannual climate variation (North Pacific Index; NPI). We developed seasonal UDs for caribou in west‐central Alberta and east‐central British Columbia, Canada, monitored with GPS collars between 1998 and 2013. We mapped the cumulative annual density of disturbance features within caribou range and used indices of overlap to determine the spatial relationship and trend between caribou UDs, anthropogenic disturbance, baseline range, alpine habitat, and the NPI. Anthropogenic disturbance increased over time, but the overlap between caribou UDs and disturbance did not. Caribou use of alpine habitat during spring, fall, and late winter increased over time, concurrent with a decrease in use of baseline range. Overlap between caribou UDs and disturbance increased during spring and fall following relatively cold, snowy winters (high NPI), but overall, climate did not explain changes in caribou distribution over time. We provide evidence supporting the hypothesis that caribou populations adjust their spatial distribution in relation to anthropogenic landscape change. Our findings could have implications for population persistence if distributional shifts result in greater use of alpine habitat during winter. Monitoring long‐term changes in the distribution of populations is a valuable component of conservation planning for species at risk in disturbed landscapes.

Wolf-caribou dynamics within the central Canadian Arctic

The severity of recent declines of barren-ground caribou (Rangifer tarandus groenlandicus) across the central Canadian Arctic has led to harvest restrictions and concerns about population recovery. Wolves (Canis lupus) are the main predator of barren-ground caribou; however, the extent that wolves influence the decline and recovery of caribou herds is unknown. Such uncertainty confounds management responses (e.g., reducing harvest, predator control). We investigated wolf–caribou dynamics on the summer range of barren-ground caribou in the Northwest Territories and Nunavut, Canada (i.e., Bathurst caribou herd). Our primary objective was to test for a numerical response of wolves to changes in the abundance and spatial distribution of caribou. Caribou experienced a >90% decline in abundance over the study period (1996–2014). Using long-term data sets (1996–2012), we developed regression models to investigate relationships between abundance indices of wolves and range-use patterns of caribou. We monitored the movements of adult female wolves fitted with global positioning system (GPS) collars representing individual packs throughout the 2013 and 2014 denning periods. We also investigated pup recruitment, an index of population decline, at a time of low caribou abundance. Finally, we developed a series of stochastic population models to understand how pup recruitment influenced wolf densities on the Bathurst range over the period of caribou decline. As caribou abundance decreased, the late-summer distribution of the Bathurst herd contracted toward the calving ground. These movements correlated with low rates of wolf pup recruitment and high den abandonment, suggesting a regulatory mechanism whereby wolf reproductive success was limited by the low availability of caribou within the denning areas. Furthermore, these data suggested a numerical response, where wolf densities decreased as caribou numbers declined. In 2014, wolf density was estimated at <4 wolves/1,000 km2. Our results suggest that these wolves exhibited a relatively strong numerical response to a single, declining prey base. Given the continued decline in the Bathurst caribou herd, the tundra wolf population on the Bathurst range has likely declined below our 2014 estimate. © 2016 The Wildlife Society.

Peary caribou distribution within the Bathurst Island Complex relative to the boundary proposed for Qausuittuq National Park, Nunavut

How caribou (Rangifer tarandus), including Peary caribou (R. t. pearyi), use their annual ranges varies with changes in abundance. While fidelity to some seasonal ranges is persistent, use of other areas changes. Consequently, understanding changes in seasonal distribution is useful for designing boundaries of protected areas for caribou conservation. A case in point is the proposed Qausuittuq (Northern Bathurst Island) National Park for Bathurst Island and its satellite islands in the High Arctic of Canada. Since 1961, Peary caribou have been through three periods of high and low abundance. We examined caribou distribution and composition mapped during nine systematic aerial surveys (1961–2013), unsystematic helicopter surveys (1989–98), and limited radio-collaring from 1994–97 and 2003–06. While migration patterns changed and use of southern Bathurst Island decreased during lows in abundance, use of satellite islands, especially Cameron Island for winter range, persisted during both highs and lows in abundance. The northeast coast of Bathurst Island was used to a greater extent during the rut and during summer at low abundance. We suggest that Park boundaries which include Cameron Island and the northeast coast of Bathurst Island will be more effective in contributing to the persistence of Peary caribou on the Bathurst Island Complex.

Decision-support model to explore the feasibility of using translocation to restore a woodland caribou population in Pukaskwa National Park, Canada

The distribution and abundance of woodland caribou (Rangifer tarandus caribou) have declined dramatically in the past century. Without intervention the most southern population of caribou in eastern North America is expected to disappear within 20 years. Although translocations have reintroduced and reinforced some populations, approximately half of caribou translocation efforts fail. Translocations are resource intensive and risky, and multiple interrelated factors must be considered to assess their potential for success. Structured decision-making tools, such as Bayesian belief networks, provide objective methods to assess different wildlife management scenarios by identifying the key components and relationships in an ecosystem. They can also catalyze dialogue with stakeholders and provide a record of the complex thought processes used in reaching a decision. We developed a Bayesian belief network for a proposed translocation of woodland caribou into a national park on the northeastern coast of Lake Superior, Ontario, Canada. We tested scenarios with favourable (e.g., good physical condition of adult caribou) and unfavourable (e.g., high predator densities) conditions with low, medium, and high numbers of translocated caribou. Under the current conditions at Pukaskwa National Park, augmenting the caribou population is unlikely to recover the species unless wolf densities remain low (&lt;5.5/1000 km2) or if more than 300 animals could be translocated.

Den site selection of wolves (Canis lupus) in response to declining caribou (Rangifer tarandus groenlandicus) density in the central Canadian Arctic

Wolves (Canis lupus) that den on the tundra of the central Arctic prey primarily on migratory barren-ground caribou (Rangifer tarandus groenlandicus). Prey densities in the vicinity of den sites are low, however, for a period each summer when caribou migrate to their calving and post-calving ranges. Eskers provide substrate where wolves can excavate den sites, but these landforms make up only a small proportion of the tundra landscape. We investigated the factors that influenced den site selection for wolves on the summer range of the Bathurst caribou herd, Northwest Territories, Canada. We used a long-term data set (1996–2012) of wolf den locations to develop a series of resource selection function (RSF) models representative of broad land-cover types, esker density, and annual variation in seasonal prey availability. We compared a temporal sequence of RSF models to investigate whether wolves altered selection patterns in response to a 90 % decline in caribou abundance (1996–2012). Eskers were selected denning habitat; the distribution of eskers may be limiting when wolf density is high. Covariates representing the seasonal distribution of caribou from early (5–18 July) and late (19 July–22 August) summer were the best predictors of den occurrence; these areas represented reliable availability of caribou over the greatest portion of the denning period. As the caribou herd declined, the seasonal summer ranges contracted northward towards the calving ground. Wolves did not exhibit a similar response. As such, the period of spatial separation between breeding wolves at den sites and the main distribution of caribou increased when herd abundance was low. The lack of a behavioural response is consistent with wolf–prey dynamics observed in other studies that suggest wolves strive to maintain consistent territories even following large decreases in resource availability. Such behaviours reduce fitness and have implications for pup survival and population growth.

Distribution of barren‐ground caribou during winter in response to fire

We investigated the influence of past fires on the large‐scale distribution of barren‐ground caribou (Rangifer tarandus groenlandicus) in the Northwest Territories, Canada, during winter. We used an information‐theoretic approach and data describing fire history, vegetation, and predation risk to develop resource selection functions that explained caribou distribution on early‐ and late‐winter ranges. We evaluated multiple sets of models constructed across years for all caribou (pooled models) and for individual caribou by period (early and late winter). Winter range habitats important to caribou were characterized by a high percentage of ground cover of lichen and herbaceous forage and a close proximity to lakes and rivers. Although caribou avoided areas densely populated with burns, there was considerable use of early‐seral habitats as well as areas adjacent to the burn boundary. Disparate selection strategies among caribou highlight the importance of investigating both individual and global resource selection models. These results suggest that at some spatial and temporal scales, individual barren‐ground caribou may be less averse to fire than previously thought.