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Anthropogenic disturbances fragmenting wildlife habitat greatly contribute to extinction risk for many species. In western Canada, four decades of oil and gas exploration have created a network of seismic lines, which are linear disturbances where seismic equipment operates. Seismic lines cause habitat fragmentation and increase predator access to intact forest, leading to declines of some wildlife populations, particularly the threatened woodland caribou, Rangifer tarandus caribou. Restoration of forests within seismic lines is an important activity to reduce habitat fragmentation and recovery caribou. We present an optimization model with the objective of guiding landscape restoration strategies that maximize the area of connected habitat for a caribou population in a fragmented landscape. We use our model to find optimal strategies for seismic line restoration in the Cold Lake Area of Alberta, Canada, a 6726-km2 expanse of boreal forest that represents prime caribou habitat. We formulate mixed integer programming models that depict the landscape as a network of interconnected habitat patches. We develop and compare formulations that emphasize the population's local or long-distance access to habitat. Optimal restoration involves a mix of two strategies: the first establishes short-distance connections between forest patches with large areas of intact habitat and the second establishes corridors between areas with known species locations and large amounts of suitable habitat. Our approach reveals the trade-offs between these strategies and finds the optimal restoration solutions under a limited budget. The approach is generalizable and applicable to other regions and species sensitive to changes in landscape-level habitat connectivity.

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.

Unspoiled wildlands of boreal landscapes provide critical habitats for wildlife. With the increase in resource development across Canada's boreal zone, woodland caribou (Rangifer tarandus caribou) and grizzly bears (Ursus arctos) are at risk of population declines. We used 4 planning scenarios with variants of these in decision-support software Marxan to allocate potential conservation priority areas for caribou and grizzly bears in boreal wildlands of the Muskwa-Kechika Management Area in northeast British Columbia, Canada. For caribou and grizzly bears across their seasonal habitats, priority areas allocated to preserve connectivity of habitat patches maintained more intact high-value habitats, with moderate opportunity cost for resource development, than those allocated under other scenarios. In winter when high-value habitats of caribou tend to coincide with resource-rich areas, priority areas allocated to preserve areas that are more vulnerable to development maintained more intact high-value habitats with higher opportunity cost (therefore greater adverse economic consequences) than those allocated in areas with lower resource potential. In growing-season (non-winter) habitats of caribou and grizzly bears, allocating priority areas toward either more vulnerable or less vulnerable areas did not substantially affect patch and landscape characteristics of conserved habitats. Priority areas intended to avoid predation risk for caribou were not effective in maintaining intact high-value habitats for caribou in these undeveloped wildlands. Conserving connectivity would best maintain most intact habitats for both species across seasons; conserving habitats most vulnerable to development also would discourage future development outside of the conserved areas in winter habitats of caribou. Findings from these conservation planning scenarios have implications globally to other areas where sensitive species are threatened by pending resource developments.

Management of wildlife often relies upon understanding mechanisms linking anthropogenic disturbance to population declines. The most-cited mechanism by which disturbance threatens boreal caribou (Rangifer tarandus caribou) is the exacerbation of apparent competition via increases in early successional forage, and subsequent changes in the densities and distributions of other prey species and gray wolves (Canis lupus). An alternative mechanism is the direct alteration of wolf distribution via positive responses by wolves to anthropogenic features. We conducted a mechanistic evaluation of hypotheses explaining human-mediated increases in boreal caribou mortality across northeast British Columbia. We evaluated support for (i) numeric apparent competition (increased prey densities) by evaluating relationships between disturbances, moose (Alces alces) density, and caribou survival. To evaluate (ii) spatial apparent competition (altered prey distribution) and (iii) wolf spatial responses (altered wolf distribution independent of prey), we modeled the relationships between disturbances and indices of caribou-moose and caribou-wolf co-occurrence and then examined predation risk for caribou as a function of co-occurrence. We did not detect any relationships between anthropogenic disturbances, moose density, and caribou survival. Although caribou-moose co-occurrence increased predation risk, we observed both positive and negative relationships between disturbances and caribou-moose co-occurrence. In contrast, caribou-wolf co-occurrence increased predation risk and was positively correlated with anthropogenic linear features. Contrary to other boreal caribou populations, our analyses demonstrate stronger support for the direct effects of anthropogenic linear features on caribou-wolf spatial overlap, leading to greater risk for caribou. Our research highlights the need for region-specific management actions to conserve and recover widely distributed species.

As global conservation actions become more urgent, informed decision-making requires robust analyses of the costs and benefits of policy options, based on available evidence. Recovery planning for threatened or endangered species must assume a cause-and-effect relationship between proposed management interventions and population responses. However, a significant portion of current knowledge about threatened or endangered species is derived from observational studies because experiments that fully meet random and controlled design criteria are largely infeasible or unethical. Large-scale field experiments are becoming more common, yet the greater uncertainty generated by what remain fundamentally observational studies can lead researchers to weak inferences about causal mechanisms, creating debate and confusion among decision-makers, planners and stakeholders. This has been an acute problem facing conservationists and governments as they struggle with the successful recovery of species in decline. In other domains where experimental evidence is difficult to collect, causal modelling has been adopted to identify causal relationships from observational data, based on a set of strong assumptions and identification rules. In Canada, significant and ongoing efforts have had limited success in reversing the population decline of woodland caribou (Rangifer tarandus caribou). We examine the scientific framework for woodland caribou recovery efforts through the lens of causal modelling, highlighting feasible steps that could be taken to improve the rigour of causal inferences.

How to mitigate the impacts of anthropogenic habitat alteration and restore ecological processes has become an imperative question facing applied ecology. One high-profile example in Canada is boreal woodland caribou, which are declining across North America largely due to anthropogenic habitat alteration and associated changes to predator-prey dynamics. Habitat restoration is increasingly being implemented to recover habitat, as is mandated by federal law. But given the extent of the disturbance and the cost to conduct restoration, evaluating the effectiveness of restoration treatments is needed for effective recovery of caribou populations. We evaluated the effectiveness of silvicultural treatments to reduce predator (wolf and bear) and prey (moose and caribou) use of linear features using a multiple lines of evidence approach. All four species were less likely to be present at treated sites than untreated sites, and daily photo capture rates of moose and wolves when present at treated sites also declined; though effect sizes were typically small. Complimenting the camera-based results, individual moose, bears, and wolves monitored with GPS collars also showed a decline in the use of treated linear features, particularly those with higher intensity treatments, though the response was non-significant. The reduction in the use of treated lines did not scale-up into a significant decline in overall line-use within the treatment area. While we found more evidence than not supporting that animals reduced use of the restoration sites, our study highlights the complexity of monitoring and evaluating the success of habitat restoration. Understanding long-term responses is imperative to ensure habitat restoration is effective.

Awareness of the impact of the global energy industry and associated landuse change on biodiversity conservation has been steadily growing amongst conservation biologists. Across Canada, 28 of 57 populations of boreal woodland caribou ( Rangifer tarandus caribou) are declining and 20 of 25 southern mountain populations are in decline with several recent high-profile extirpations. Declines stem from widespread landuse change from energy development and forestry that will take decades to recover, if ever. In Western Canada's Boreal forest, a globally significant oil and gas industry has emerged that is the biggest source of foreign oil to US markets. All woodland caribou populations overlapping oil and gas development in oil-rich Alberta are in rapid decline, shrinking by 50% every 8 years. After a decade of delay, the Federal government released recovery plans under the Canadian Species-at-Risk Act (SARA) in 2012 and 2014 for these two caribou ecotypes, and will audit provincial compliance in 2017. Yet recovery actions have been inadequate, and have relied on wolf control as a short-term solution. Given the stark reality, conservation triage might be expected. Instead, the conservation objective at Federal and Provincial levels remains legally committed to recovery of all populations despite the paradox of continued declines. I suggest the reason for ineffective conservation planning is the staggering cost of effective habitat protection that far exceeds $150 billion (CDN) in Alberta alone. Declines of woodland caribou also allegedly violate Canadian Aboriginal treaty rights that have been challenged in court. This complex conservation case-study urgently illustrates the need for strategic conservation triage at provincial and national levels. And more generally, caribou conservation demonstrates the challenge of using national endangered species legislation to retroactively counteract the global energy industry without strategic conservation planning coordinated with energy and cultural policies.

Ecotypes offer an essential framework for conservation and ecological understanding, but their identification can be problematic. These challenges are exemplified by the sedentary and migratory ecotypes of woodland caribou (Rangifer tarandus caribou). In Ontario, Canada, reliable discrimination based on morphology, pelage, or genetics has been unsuccessful. We tested the discriminatory power of locational and movement metrics as candidate indicators of discrete behaviours for 132 GPS-tracked female caribou. We assigned each animal to an ecotype each year using two variables which demonstrated the strongest bi-modality and the best discriminatory power: percent of calving season locations within the Hudson Bay Lowland and mean distance to treeline during calving season. The analysis revealed two distinct modes. None of 101 caribou tracked for more than 1 year switched behaviours, implying the distinction may be permanent. Although there was no significant difference in morphology between ecotypes, mean aggregation metrics and calving dates were significantly different. Geographic distribution of these ecotypes showed substantial range overlap, particularly during winter, which presents challenges for conservation of the sedentary ecotype, a threatened designatable unit under federal and provincial legislation. Woodland caribou − with its cryptic ecotypes, discernible from differences in spatial behaviour − illustrate the importance of this type of analysis for identifying significant units for protection, understanding habitat relationships, and delineating ranges for habitat protection.

Large-scale conservation planning entails the establishment of protected area networks that retain substantive natural habitat, biodiversity, and functional connectivity, but developing such networks at the spatial extent needed for meeting global targets involves considerable logistical, political, and social challenges. Normally, governments oversee development of protected area networks, but in the absence of political leadership private initiatives may offer a reasonable alternative approach in conservation planning. We review the Canadian Boreal Forest Agreement (CBFA), a private conservation planning initiative established by forestry companies and environmental organizations that suspends permitted logging activities on roughly 29 million hectares of boreal forest in Canada. The CBFA is touted as a milestone in conservation planning, multi-stakeholder cooperation, and woodland caribou conservation. Yet, the CBFA: 1) involves public land but excludes federal, provincial and aboriginal governments; 2) is not legally binding or necessarily transferrable upon sale of forest tenures; and 3) exempts industrial activities other than logging. Covering 4.6% of the boreal region of Canada, CBFA land tenures do not include most boreal ecozones and do not conform to standard guidelines for designing effective protected area networks. Further, the CBFA does not anticipate effects of climate change, which by 2080 likely will render land tenures unsuitable for caribou, the flagship species of the agreement. We conclude that private initiatives like the CBFA may constitute positive, initial steps toward large-scale conservation planning, but their successful integration into protected area networks will require scientifically robust and transparent efforts that are more fully coordinated with public initiatives.

Restoration of degraded habitats is increasingly used to mitigate the effects of anthropogenic landscape change on wildlife populations, but wildlife responses to habitat restoration are often assumed rather than verified. In the western Canadian boreal forest, restoration of seismic lines-linear corridors cut for oil exploration-has been proposed to mitigate declines in woodland caribou (Rangifer tarandus caribou) driven by altered predator-prey dynamics in industrialized landscapes. Seismic lines fragment caribou habitat, facilitate predator (wolves Canis lupus and black bears Ursus americanus) movements, and may enhance apparent competition from white-tailed deer (Odocoileus virginianus) and moose (Alces alces). Here, we tested the assumption that restoration provides immediate wildlife conservation benefits, using a caribou-boreal forest case study. We used camera traps to monitor seismic line use by caribou, their competitors, and predators following restoration in northeastern Alberta. We assessed species responses to four line strata: two restored (active and passive) and two unrestored (human-use and control). Three-to-six years after restoration, white-tailed deer preferred unrestored seismic lines over actively restored lines, while wolves preferred human-use lines but did not avoid restored lines. Caribou preferred lines in lowland habitat and lines surrounded by low linear density regardless of restoration. Species responses to restoration were muted, indicating that restoration alone may not be immediately effective in stabilizing threatened caribou populations. Our results highlight that wildlife responses to restoration must be tested. We recommend rigorous wildlife monitoring following restoration, particularly when the indirect, interspecific effects of habitat change drive species endangerment or recovery.

Habitat change is a major driver of species distribution and persistence, but there have been few recorded extinction events for terrestrial mammals across Canada. Currently, we are observing the decline, extirpation, and perhaps extinction of several evolutionarily significant units of woodland caribou ( Rangifer tarandus caribou ), an iconic and cultural keystone species. We used an extensive set of caribou locations (5 subpopulations, 102 animals, 270,808 GPS-collar locations) collected over 11 years within the Central Mountain Designatable Unit to develop species distribution models that quantified avoidance by caribou of anthropogenic and natural disturbance features. Those empirical relationships allowed us to measure the loss of habitat over a 22-year period and correlate habitat change with measured population decline. The disturbance responses for caribou were complex and varied by season and subpopulation. We modelled a zone of influence for roads (1.75 km), seismic and pipelines (2.5 km), oil and gas features (4.25 km), cutblocks (5.5 km), burns (8.0 km), and coal mines (3.0 km). When the distribution models for each subpopulation were applied to the respective seasonal ranges, we measured a maximum loss in high-quality habitat of 65.9%. The reduction in habitat was strongly correlated with the annual multiplicative growth rate of 5 subpopulations of caribou. At current rates of habitat loss and population decline, these caribou, a significant component of Canada’s biodiversity, are unlikely to persist. Although the factors leading to extinction are complex, the cumulative impacts of industrial development are a correlative if not causative factor.

Boreal caribou, an ecotype of woodland caribou (Rangifer tarandus caribou), are closely associated with the boreal forest, which has been significantly modified by anthropogenic activities over the last century. The species’ response to disturbances has been extensively researched – a reflection of the importance of habitat loss in the decline of boreal caribou. We investigated how female caribou cope with disturbances using GPS telemetry data collected on 48 females in a highly managed landscape in Quebec, Canada, between 2004 and 2010, using home-range size as a proxy of caribou space use behaviour. Individuals were found to expand their home ranges as the amount of disturbances in their habitat increased, up to a point where further increase caused home range contraction. The density of major roads and the proportion of clearcuts had an important impact on space use throughout the whole year, but the impact of roads was particularly important during calving, summer and rut, while the impact of clearcuts prevailed in spring, early and late winter. Furthermore, we found that a more convoluted shape of cutblocks amplified the effect of clearcuts on caribou space use. These non-linear responses suggest that there is a limit to the adaptability of caribou in coping with anthropogenic disturbances. Although home range expansion could affect survival through the use of unknown habitats, individuals confined in smaller home ranges could be forced into an ecological trap and be more easily detected by predators, making current disturbance levels in the boreal forest and their cumulative amount in the landscape a major issue for the conservation of these boreal caribou populations.

Understanding the impact of indirect habitat loss resulting from avoidance of human infrastructure is an important conservation priority. We evaluated resource selection for 10 global positioning system collared northern mountain woodland caribou (Rangifer tarandus caribou) in British Columbia, Canada, with seasonal resource selection functions (RSF) developed at the second-order (landscape) and third-order (within home range) scales. To estimate how much habitat was lost due to avoidance, we estimated the zone of influence (ZOI) around multiple developments and modeled realized and potential habitat. Potential habitat was approximated by removing the ZOI from RSF models. By calculating the spatial difference between potential and realized habitat we estimated the amount of indirect habitat loss. Caribou displayed hierarchical avoidance of development, with the greatest avoidance occurring at the secondorder. During both seasons caribou avoided high-use roads by 2 km and low-use roads by 1 km. In winter, caribou avoided town by 9 km compared to 3 km in summer. However, in summer caribou avoided mines by 2 km and cabins and camps by 1.5 km, while in winter when human activity was low, avoidance of these features was minor. As a result of avoidance of the cumulative ZOI, approximately 8% and 2% of high quality habitat was lost in the study area in winter and summer, respectively. Our study provides an approach to identify the extent and quality of habitat influenced by indirect avoidance. Conservation efforts should prioritize protecting areas of high quality habitat degraded by avoidance in the vicinity of human development.

Conservation of forest-dwelling caribou (Rangifer tarandus caribou) is of great concern across most of its range. Anthropogenic disturbances, primarily logging activities, have been identified as the most important cause of caribou decline, although the mechanisms underlying this decline are not fully understood. Caribou commonly display fidelity to calving sites or seasonal ranges, but the potential role of this life-history trait has been largely overlooked in research and conservation planning. This is surprising because sites and ranges with high inter-annual use should have high conservation value. We investigated the relationship between habitat disturbances and home-range fidelity of forest-dwelling caribou across three study sites in Quebec, Canada, using a broad range of natural and anthropogenic disturbances. Between 2004 and 2007, we tracked 47 adult female caribou using GPS collars. Home-range fidelity varied between seasons, being higher during calving and summer, and lower during winter. Caribou reduced fidelity following natural and anthropogenic disturbances, the latter having a stronger negative influence. Anthropogenic disturbances had a strong negative impact on home-range fidelity during annual, summer and winter periods, whereas natural disturbance was the dominant factor during calving. Despite this negative influence on fidelity, caribou tended to demonstrate range fidelity even in study sites most impacted by human activities. Habitat disturbances could produce two possible outcomes for caribou conservation: (1) a trend for females to reduce home-range fidelity which could translate into lower calf and female caribou survival through reduced familiarity with food distribution, escape cover and predation risk and (2) a global tendency to maintain range fidelity even in a drastically modified landscape which could turn into an ecological trap, particularly for calves when predation risk increases due to increased black bear density in early successional forests. Taking range fidelity behavior into consideration during forest management planning could direct conservation efforts toward the best available sites and therefore facilitate caribou persistence in managed landscapes.

Prioritization of conservation efforts for threatened and endangered species has tended to focus on factors measuring the risk of extirpation rather than the probability of success and cost. Approaches such as triage are advisable when three main conditions are present: insufficient capacity exists to adequately treat all patients, patients are in a critical state and cannot wait until additional capacity becomes available, and patients differ in their likely outcome and/or the amount of treatment they require. The objective of our study was to document the status of woodland caribou (Rangifer tarandus) herds in Alberta, Canada, with respect to these three conditions and to determine whether a triage approach might be warranted. To do this we modeled three types of recovery effort – protection, habitat restoration, and wolf control – and estimated the opportunity cost of recovery for each herd. We also assessed herds with respect to a suite of factors linked to long-term viability. We found that all but three herds will decline to critical levels (

Conservation of remaining woodland caribou ( Rangifer tarandus caribou ) populations requires land management strategies that not only maintain caribou habitat, but also favour habitat connectivity. This study presents and field tests graph theory-based measures of landscape connectivity, and demonstrate an association between the distribution of woodland caribou and well-connected winter habitat. Cost values for the intervening land cover types were determined based on the probability of selection relative to high-quality winter habitat. Habitat connectivity was then represented by linking high-quality habitat patches along least-cost paths through this parameterized cost surface. A randomization procedure was used to assess the animal’s association with habitat connected at increasing distance thresholds to identify appropriate scales of response. A strong relationship was obtained between large clusters of high-quality winter habitat patches and winter GPS telemetry location points (November 1–March 15) from two woodland caribou herds in Manitoba, Canada. This relationship was stronger when only late winter location points (January 1–March 15) were used. Our results highlight the importance of accounting for the spatial configuration of habitat on the landscape and the intervening land cover types when assessing range quality for woodland caribou. They also provide support for the use of graph theory to assist in identifying core activity areas for woodland caribou and key linkages between these areas and other parts of the landscape.

Mountain caribou, an ecotype of woodland caribou, are endangered due to the loss and fragmentation of old forests on which they depend. However, a wider array of natural and human factors may limit caribou persistence and isolate populations, and understanding these may help to stop or reverse population declines by forecasting risk and targeting core habitat areas and key linkages for protection, enhancement or restoration. Across most of the historic range of mountain caribou, we conducted a bi-level analysis to evaluate factors related to the persistence of, and landscape occupancy within, remaining subpopulations. We used caribou location data from 235 radio-collared animals across 13 subpopulations to derive a landscape occupancy index, while accounting for inherent sampling biases. We analyzed this index against 33 landscape variables of forest overstory, land cover, terrain, climate, and human influence. At the metapopulation level, the persistence of subpopulations relative to historic range was explained by the extent of wet and very wet climatic conditions, the distribution of both old (>140 yr) forests, particularly of cedar and hemlock composition, and alpine areas. Other important factors were remoteness from human presence, low road density, and little motorized access. At the subpopulation level, the relative intensity of caribou landscape occupancy within subpopulation bounds was explained by the distribution of old cedar/hemlock and spruce/subalpine fir forests and the lack of deciduous forests. Other factors impeding population contiguity were icefields, non-forested alpine, hydro reservoirs, extensive road networks, and primary highway routes. Model outputs at both levels were combined to predict the potential for mountain caribou population persistence, isolation, and restoration. We combined this output with the original occupancy index to gauge the potential vulnerability of caribou to extirpation within landscapes known to have recently supported animals. We discuss implications as they pertain to range-wide caribou population connectivity and conservation.

We assessed the impact of ecotourist visits during winter on woodland caribou Rangifer tarandus caribou time budgets in the Charlevoix Biosphere Reserve, Canada. We compared the behaviour of caribou during and after ecotourist visits with their behaviour during days without visits. In the presence of ecotourists, caribou increased time spent vigilant and standing, mostly at the expense of time spent resting and foraging. After visits, caribou tended to rest more than during control days. Caribou reduced time spent foraging during ecotourist visits as the number of observers increased. The impact of ecotourists appeared to decrease as winter progressed. Visits were short ( x =39.3 min) and caribou never left their winter quarters because of human presence. However, caribou abandoned their wintering area twice in response to wolf presence. Although winter is a difficult period of the year for caribou, our results suggest that with proper precautions caribou in Charlevoix can tolerate ecotourist visits.