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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. [ABSTRACT FROM AUTHOR]

Lethal population control has a history of application to wildlife management and conservation. There is debate about the efficacy of the practice, but more controversial is the ethical justification and methods of killing one species in favor of another. This is the situation facing the conservation of woodland caribou (Rangifer tarandus caribou) in Canada. Across multiple jurisdictions, large numbers of wolves (Canis lupus), and to a lesser extent bears (Ursus americanus) and coyotes (C. latrans), are killed through trapping, poisoning or aerial shooting to halt or reverse continued declines of woodland caribou. While there is evidence to support the effectiveness of predator management as a stop‐gap solution, questions remain about the extent to which this activity can make a meaningful contribution to long‐term recovery. Also, there are myriad ethical objections to the lethal removal of predators, even if that activity is in the name of conservation. Debates about predator management, just one of numerous invasive actions for maintaining caribou, are made even more complex by the conflation of ethics and efficacy. Ultimately, long‐term solutions for the recovery of caribou require governments to stop delaying difficult decisions that address the real causes of population decline, habitat change. [ABSTRACT FROM AUTHOR]

Non‐renewable resource extraction contributes greatly to degradation of wildlife habitats in boreal landscapes. In western Canada, oil and gas exploration and extraction have left a dense network of linear disturbances (seismic lines) and abandoned well pads that have fragmented boreal forest. Among multiple ecological effects, these disturbances have increased predator access to the preferred habitat of some wildlife taxa, most notably boreal woodland caribou, resulting in population declines. Restoration of seismic lines and abandoned well pads is a critical activity to improve the recovery of woodland caribou populations. We present a linear programming model that optimally allocates restoration efforts to maximize the access of caribou to nearby undisturbed habitat in a fragmented landscape. We applied the model to examine restoration scenarios in the Cold Lake First Nations area in northeastern Alberta, Canada, which includes caribou habitat but also areas of active oil and gas extraction. The model depicts the landscape as a network of interconnected habitat patches and combines three network flow sub‐problems. The first sub‐problem enforces the spatial connectivity of the remaining network of unrestored sites. The second sub‐problem maximizes access to suitable habitat from the restored locations and the third sub‐problem ensures the allocation of restoration activities in as few spatially contiguous restoration projects as possible. The approach is generalizable and applicable to assist restoration planning in other resource extraction regions and for other taxa. [ABSTRACT FROM AUTHOR]

Canada's federal recovery strategy for boreal woodland caribou (Rangifer tarandus caribou) classifies areas burned by forest fire as disturbed habitat. This assignment of fire as a disturbance has potential economic and social implications across Canada, and influences plans and actions to achieve caribou conservation and recovery. Previous researchers have reported caribou avoid burned habitat, but these studies did not typically consider unburned residual patches within fire perimeters. Additionally, the implications of burned habitat on individual caribou survival is unclear. We examined resource selection by boreal woodland caribou of burns, and unburned residual patches, using global positioning system (GPS) locations for 201 caribou across 6 caribou populations in Alberta, Canada. We also examined if burned habitat affected the survival of adult female caribou. Caribou avoided burns and unburned residual patches. Increased use of burned habitats, however, did not lower the survival of adult caribou. Collectively, these results provide evidence to support current assertions that burns, and the embedded unburned residual patches are not preferred caribou habitat and increase our understanding of the implications of forest fire for caribou vital rates. Our investigation offers important information about the role of forest fire in caribou ecology and enhances the identification of disturbed habitat under recovery strategy guidelines to effectively address caribou population declines. © 2021 The Wildlife Society. : Woodland caribou in Alberta, Canada avoid burned habitat including unburned residual patches; however, there was no relationship between burned habitat use and adult female survival. This suggests fire disturbance is not a key influence of caribou population persistence, and we recommend reevaluation of the current approach listed in the federal boreal caribou recovery strategy that includes anthropogenic and fire disturbance in a cumulative assessment of disturbed habitat. [ABSTRACT FROM AUTHOR]

Boreal forests provide numerous ecological services, including the ability to store large amounts of carbon, and are of significance to global biodiversity. Increases in industrial activities in boreal landscapes since the mid‐20th century have added to concerns over biodiversity loss and climate change. Boreal forests are home to dwindling populations of boreal caribou Rangifer tarandus caribou in Canada, a species at risk that requires large, undisturbed landscapes for persistence. In 2012, the Canadian government defined critical habitat for boreal caribou by relating calf recruitment to disturbances. Some have questioned whether the recruitment relationship can be extrapolated beyond the environmental conditions represented in the analysis.We examined the effects of human disturbances and fire (alone and in combination) on variation in recruitment and adult female survival using data from 58 study areas in Canada. Top models were used in aspatial scenarios of landscape change to evaluate the efficacy of the critical habitat definition in achieving the recovery objectives for boreal caribou in two contrasting landscapes: Little Smoky, dominated by high levels of human disturbances, and the northern boreal shield of Saskatchewan (SK1), dominated by fire.The top recruitment model suggested the negative effect of fire was three to four times smaller than human disturbances. The top adult female survival model included human disturbances only. These results re‐affirm that human disturbances are the primary factor contributing to boreal caribou declines.Our aspatial scenarios suggested that undisturbed habitat would have to increase to ≥68% for Little Smoky to maintain a self‐sustaining population of boreal caribou with some degree of certainty. In contrast, the SK1 population was self‐sustaining with 40% undisturbed habitat when fire disturbance predominates, but could become vulnerable with increases in human disturbances (8%–9%).Policy implications. Boreal caribou are listed as threatened under Canada's Species at Risk Act. Our results suggest that the 65% undisturbed critical habitat designation in Canada's boreal caribou Recovery Strategy may serve as a reasonable proxy for achieving self‐sustaining populations of boreal caribou in landscapes dominated by human disturbances. However, some populations may be less or more vulnerable, as illustrated by the scenarios in a landscape dominated by fire (SK1). Continued population monitoring will be essential to assessing the effectiveness of land management strategies developed for boreal caribou recovery, especially with climate change. [ABSTRACT FROM AUTHOR]

In western Canada, decades of oil-and-gas exploration have fragmented boreal landscapes with a dense network of linear forest disturbances (seismic lines). These seismic lines are implicated in the decline in wildlife populations that are adapted to function in unfragmented forest landscapes. In particular, anthropogenic disturbances have led to a decline of woodland caribou populations due to increasing predator access to core caribou habitat. Restoration of seismic lines aims to reduce the landscape fragmentation and stop the decline of caribou populations. However, planning restoration in complex landscapes can be challenging because it must account for a multitude of diverse aspects. To assist with restoration planning, we present a spatial network optimization approach that selects restoration locations in a fragmented landscape while addressing key environmental and logistical constraints. We applied the model to develop restoration scenarios in the Redrock-Prairie Creek caribou range in northwestern Alberta, Canada, which includes a combination of caribou habitat and active oil-and-gas and timber extraction areas. Our study applies network optimization at two distinct scales to address both the broad-scale restoration policy planning and project-level constraints at the level of individual forest sites. We first delineated a contiguous set of coarse-scale regions where restoration is most cost-effective and used this solution to solve a fine-scale network optimization model that addresses environmental and logistical planning constraints at the level of forest patches. Our two-tiered approach helps address the challenges of fine-scale spatial optimization of restoration activities. An additional coarse-scale optimization step finds a feasible starting solution for the fine-scale restoration problem, which serves to reduce the time to find an optimal solution. The added coarse-scale spatial constraints also make the fine-scale restoration solution align with the coarse-scale landscape features, which helps address the broad-scale restoration policies. The approach is generalizable and applicable to assist restoration planning in other regions fragmented by oil-and-gas activities. • The proposed methodology can assist restoration of linear disturbances in forest landscapes. • Optimization model supports restoration decisions by accounting for both operational and wildlife conservation objectives. • The two-tier approach addresses both the broad-scale policy goals and practical planning at the level of individual sites. • The approach is applicable in areas with presence of both resource extraction activities and endangered species populations. [ABSTRACT FROM AUTHOR]

Tradeoffs between cost and recovery targets for boreal caribou herds, threatened species in Alberta, Canada, are examined using a dynamic cost minimization model. Unlike most approaches used for minimizing costs of achieving threatened species targets, we incorporate opportunity costs of surface (forests) and subsurface resources (energy) as well as direct costs of conservation (habitat restoration and direct predator control), into a forward looking model of species protection. Opportunity costs of conservation over time are minimized with an explicit target date for meeting species recovery targets; defined as the number of self-sustaining caribou herds, which requires that both habitat and population targets are met by a set date. The model was run under various scenarios including three species recovery criteria, two oil and gas price regimes, and targets for the number of herds to recover from 1 to 12. The derived cost curve follows a typical pattern as costs of recovery per herd increase as the number of herds targeted for recovery increases. The results also show that the opportunity costs for direct predator control are small compared to habitat restoration and protection costs. However, direct predator control is essential for meeting caribou population targets and reducing the risk of extirpation while habitat is recovered over time. [ABSTRACT FROM AUTHOR]

We present a forest harvest scheduling model that meets timber harvest targets while maximizing a proxy measure of woodland caribou ( Rangifer tarandus caribou (Gmelin, 1788)) habitat based on the configuration of preferred habitat on the landscape. Woodland caribou within the boreal forest region in Canada tend to prefer mature jack pine forest stands, which tend to be rich in their preferred resource, lichen, and also reduce predation pressure. This can create conflict with industrial wood supply needs. We designed a model that can be used to identify good harvest scheduling plans given these competing objectives. Our approach is to use a series of sequential linear programming models that are solved within a replanning framework. Specifically, each individual linear programming model seeks to produce a solution that will meet timber harvest targets while minimizing the harvest of high-quality woodland caribou habitat stands. Stands are assessed with respect to their suitability as woodland caribou habitat based on their contribution to the overall landscape equivalent connected area (ECA), a combined spatial measure of preferred habitat amount and its connectivity. We used our model for a case study of the Trout Lake Forest in northwestern Ontario, Canada, and found that our model creates approximately 10% more caribou habitat than an earlier heuristic procedure and 30% more caribou habitat than the prevailing woodland caribou habitat forest management plan in the Trout Lake Forest while meeting the same timber harvest targets. [ABSTRACT FROM AUTHOR]

Conserving species-at-risk requires quantifiable knowledge of the key drivers of population change. Non-linear demographic responses to habitat loss have been documented for many species and may serve to establish quantitative habitat thresholds for management purposes. In Canada, boreal populations of woodland caribou are considered threatened; Environment Canada's empirical model of calf recruitment-range disturbance suggests that at least 65% undisturbed habitat is required to ensure viability. We tested the relationship upon which this conservation guideline is based by pairing demographic estimates with range conditions over a 10-year period for three boreal caribou populations. Our objectives were (1) to evaluate evidence of intra-population demographic responses to fluctuations in range quality over time; (2) to evaluate inter-population differences in demographic responses to cumulative range disturbances; and (3) to evaluate the sensitivity of disturbance tolerance thresholds to variation in local population demography. We found strong evidence in support of the disturbance-recruitment relationship for within-population responses over time (R = 0.77). Mixed effects logistic regression modeling revealed variations in local population responses to cumulative habitat depletion. Range-specific disturbance thresholds derived from Monte Carlo simulations were highly elastic in response to observed variation in local population demography, suggesting that 65% undisturbed habitat is insufficient when adult female survival and/or sex ratio is suboptimal. Study populations were determined to be not self-sustaining (Pr(λ ≥ 0.99) = 37-47%). Adult survival was comparable to estimates reported elsewhere despite Aboriginal harvesting for subsistence purposes. Results underscored potential trade-offs between forest harvesting and wildlife habitat conservation. Protection and restoration of sufficient quantities of undisturbed habitat, particularly via road reclamation, is essential for caribou population recovery. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The federal recovery strategy for boreal woodland caribou (Rangifer tarandus caribou) sets a goal of self-sustaining populations for all caribou ranges across Canada. All caribou herds in Alberta are currently designated as not self-sustaining and the recovery strategy requires an action plan to achieve self-sustaining status. At the same time, continued natural resource extraction in caribou ranges may be worth hundreds of billions of dollars. Some regulatory bodies have recognized an opportunity for biodiversity offsets to help meet the caribou recovery strategy's goals while still permitting economic benefits of development. In this review, we evaluate offset opportunities for caribou in Alberta and practical impediments for implementation. We conclude that a number of actions to offset impacts of development and achieve no net loss or net positive impact for caribou are theoretically feasible (i.e., if implemented they should work), including habitat restoration and manipulations of the large mammal predator-prey system. However, implementation challenges are substantial and include a lack of mechanisms for setting aside some resources for long periods of time, public opposition to predator control, and uncertainty associated with loss-gain calculations. A framework and related policy for offsets are currently lacking in Alberta and their development is urgently needed to guide successful design and implementation of offsets for caribou. [ABSTRACT FROM AUTHOR]

Woodland caribou ( Rangifer tarandus caribou) are a species of increasing conservation concern across North America. Throughout much of boreal Canada, human developments, including forestry and energy development, are now accepted causes of the decline in the number and distribution of caribou. One of the hypothesised mechanisms for the decline is altered predator-prey dynamics. We quantified the impacts of a variety of industrial activities on gray wolf ( Canis lupus) and caribou interactions at a regional scale. We used animal locations collected with global positioning system collars and field data to examine how a range of industrial developments influenced the movements of wolves. We quantified the speed of wolf movements and the tortuosity of movement paths at two spatiotemporal scales across forested boreal and mountainous environments occupied by woodland caribou. Habitat and disturbance features better explained wolf movements during the weekly scale. In general, linear movements increased during winter, which paralleled past studies that suggested linear travel by wolves was associated with deep snow and the increased maintenance and patrol of territories. Wolves decreased movement rates but not sinuosity within close proximity to disturbance features, thus implying behaviours near such features were more closely associated with prey searching and hunting. Alternatively, wolves increased movement rates and linear travel through areas with high densities of linear and non-linear industrial features; this response suggested that wolves avoided spending time in high-risk areas associated with human activities. Results of this study further our understanding of wolf distribution and behaviour in habitats supporting populations of caribou within a matrix of industrial developments. [ABSTRACT FROM AUTHOR]

Highlights: [•] We examined lichen growth during 15months for three Cladonia species in boreal forests. [•] We compared lichen growth between unharvested control plots, partial cut plots, and clearcut plots. [•] Growth rates of Cladonia stellaris and C. rangiferina were lower in controls than in partial cuts and clearcuts. [•] Lichen cover of the three Cladonia species did not differed between partial cut plots and control plots. [ABSTRACT FROM AUTHOR]

Caribou (Rangifer tarandus) are an important ecological, cultural and economic resource in Yukon, Canada. Three caribou ecotypes occur within Yukon: Grant's (R. t. granti), northern mountain (R. t. caribou), and boreal (R. t. caribou). Northern mountain caribou are classified as a species of special concern under Canada's Species at Risk Act, and a national management plan for northern mountain caribou was recently completed. Twenty-six northern mountain caribou herds occur at least partially within Yukon, representing approximately 30,000 - 35,000 animals. Active monitoring of Yukon's northern mountain caribou began in earnest in the early 1980s. To date, over 200 fall composition surveys have been carried out, over 1000 animals have been fitted with radio-collars, and nearly 40 formal population estimates have been completed. Disease and contaminant monitoring of these caribou has indicated relatively low disease prevalence and contaminant loading. Northern mountain caribou are harvested in Yukon, with an average of 230 caribou harvested per year by licensed hunters (1995 - 2012) and an unknown number by First Nation hunters. Future challenges related to caribou management and conservation in Yukon include increasing levels of industrial development primarily through mineral exploration and development, ensuring harvest of these herds is conducted sustainably given the absence of total harvest information, inter-jurisdictional management of shared herds, existing uncertainty surrounding herd distribution and delineation, and dealing with vehicle-related mortality of caribou for certain herds. Overall, the population status (i.e., trend) of eight herds is known, with two increasing, two decreasing, and four stable. [ABSTRACT FROM AUTHOR]

The article discusses research by biologists John Fryxell, Jim Baker, and team into the decline of woodland caribou (Rangifer tarandus caribou) in Ontario, Canada using population viability analysis (PVA) to identify potential causes and conservation remedies. Two ecotypes of Ontario caribou are described, one that migrates between tundra and boreal forest and one which remains in the boreal forest in every season. The caribou habitat has been altered by deforestation from logging and mining, as well as changes in forest composition caused by global warming. The PVA looked at factors such as increased competition between caribou and moose and predation by wolves as the species are driven into new habitats, parasitism by black flies, and caribou feeding on mosses and lichens.

Abstract: Alberta woodland caribou (Rangifer tarandus) are classified as threatened in Canada, and a local population in the west-central region, the Little Smoky herd, is at immediate risk of extirpation due, in part, to anthropogenic activities such as oil, gas, and forestry that have altered the ecosystem dynamics. To investigate these impacts, we have developed a spatially explicit, agent-based model (ABM) to simulate winter habitat selection and use of woodland caribou, and to determine the relative impacts of different industrial features on caribou habitat-selection strategies. The ABM model is composed of cognitive caribou agents possessing memory and decision-making heuristics that act to optimize tradeoffs between energy acquisition and disturbance. A set of environmental data layers was used to develop a virtual grid representing the landscape over which caribou move. This grid contained forage-availability, energy-content, and predation-risk values. The model was calibrated using GPS data from caribou radio collars (n = 13) deployed over six months from 2004 to 2005, representing caribou winter activities. Additional simulations were conducted on caribou habitat-selection strategies by assigning industrial features (i.e., roads, seismic lines, pipelines, well sites, cutblocks and burns) different levels of disturbance depending on their type, age, and density. Differences in disturbance effects between industry features were confirmed by verifying which resultant simulations of caribou movement patterns most closely match actual caribou distributions and other patterns extracted from the GPS data. The results elucidate the degree to which caribou perceive different industry features as disturbance, and the differential energetic costs associated with each, thus offering insight into why caribou are choosing the habitats they use, and consequently, the level and type of industry most likely to affect their bioenergetics and fitness. [Copyright &y& Elsevier]

Fire management is an important conservation tool in Canada's national parks. Fires can benefit some species, while others may be negatively impacted. We used GPS and VHF collar data for 47 wolves from 12 separate packs and 153 caribou from 5 separate herds, and resource selection analysis to model the effects of fire on these species' habitat and potential interactions. Resource selection modeling showed that wolves select for burned areas and areas close to burns, presumably due to the presence of primary prey (i.e., elk and moose), while caribou avoid burns. Fire reduced the amount of high quality caribou habitat (a direct effect), but also increased the probability of wolf-caribou overlap (an indirect effect). We delineated a spatial index of caribou "safe zones" (areas of low overlap with wolves), and found a positive relationship between the proportion of a herd's home range represented by "safe zone" in winter and population size (P = 0.10, n=4). While currently-planned prescribed fires in Banff and Jasper reduced the amount of quality caribou habitat by up to 4%, they reduced the area of "safe zones" by up to 7%, varying by herd, location, and season. We suggest that conservation managers should account for the indirect, predator-mediated impacts of fire on caribou in addition to direct effects of habitat loss. [ABSTRACT FROM AUTHOR]

Our objective was to determine the influence of temporal sampling regime on the characteristics of individual female caribou home ranges and to explore implications of these findings to the conservation of caribou. The study population was 24 adult female caribou monitored for between 4 and 11 consecutive years between 1986 and 2009 from the Red Wine Mountain (RWM) and Lac Joseph (LJ) herds of boreal caribou in Labrador. We evaluated the influence of length of the monitoring period on the size of home ranges and fidelity of caribou to their ranges by measuring the percent overlap of multi-annual ranges on the total time period a caribou was collared and by calculating displacement between centroids of annual and multi-annual ranges for a given caribou. We found that the size of the range increased with each additional year of monitoring--initially at a rate greater than 20% per year, and then more slowly until an asymptote was reached after 7 years. The distance ratio declined with an increase in the monitoring interval until after approximately 6 years of monitoring. Finally, we evaluated trade-offs between monitoring interval and sample size by measuring the proportion of the total herd range captured by multi-annual ranges for given monitoring interval and sample size combinations. Caribou with the longest monitoring interval inevitably captured the greatest portion of the range at each given sample size. Only monitoring intervals of 4 years or greater captured more than 65% of the herd range even when sample size was doubled for shorter monitoring intervals. Our results suggest that long term monitoring is important when defining the extent of caribou ranges. [ABSTRACT FROM AUTHOR]

We describe the protocols of two mark-resight abundance surveys, using temporary dye-marks, for the Aishihik woodland caribou (Rangifer tarandus caribou) and wood bison (Bison bison athabascae) populations (herds) in the southwest Yukon Territory, Canada. We also provide recommendations based on experiences from these surveys for biologists and managers considering this approach. The Aishihik woodland caribou herd was the focus of intensive management in the 1990s aimed at recovering the herd. Following recovery activities, a target size of 2000 animals was determined and the Champagne-Aishihik Traditional Territory Community-Based Wildlife Management Plan recommended an estimate of the herd's size be completed before the year 2013. We used an aerial mark-resight approach to estimate the herd's size in March 2009. Caribou (n = 59) were marked from a helicopter with temporary dye, delivered via a CO -powered rifle. Two independent resighting sessions were subsequently carried out via helicopter. The herd was estimated at 2044 animals (90% CI: 1768 - 2420) with an overall resighting rate of 0.47. The mean annual growth rate (?) of the herd from 1997 - 2009 was 1.05 (SE = 0.01). The Aishihik wood bison herd was estimated at 1151 (90% CI: 998 - 1355). Our study suggests that ungulates temporarily marked with dye can be successfully used to obtain statistically sound population estimates. [ABSTRACT FROM AUTHOR]

Manitoba Hydro is responsible for the continued supply of energy to meet the needs of the province and is committed to protecting the environment when planning the construction and operation of its facilities. Corporate policy dictates ongoing improvement of Environmental Management Systems (EMS) in order to meet or surpass regulatory requirements. Environmental objectives are reviewed annually and programs are modified when necessary to address improvements in environmental performance. Manitoba Hydro plans and constructs major transmission projects throughout northern Manitoba which includes areas occupied by boreal woodland caribou. In recognition of the potential issues associated with hydro transmission construction in boreal caribou range, Manitoba Hydro hosted an expert workshop on May 8, 2007 to provide objective advice in the development of a draft corporate strategy that effectively directs targeted monitoring and research for environmental assessment and mitigation. The workshop focused on assessing the potential threats to boreal woodland caribou from a transmission line construction and operation perspective, and identifying appropriate approaches in site selection and environmental assessment (SSEA) and long-term monitoring and research. A total of nine threat categories were reviewed to determine the degree and magnitude of potential effects that may result from transmission construction and operation; and of the original nine, five final threat categories were delineated. The main elements of the workshop provided strategic approaches for proactive pre-construction monitoring, research on recruitment and mortality for local populations impacted by ROWs and control areas, and various habitat monitoring, management, and mitigation techniques. Research and monitoring priorities have been identified and continued collaboration with Manitoba Conservation and other land users were also identified. [ABSTRACT FROM AUTHOR]

Woodland caribou in the southern portion of Jasper National Park have declined from an estimated 435 in the mid 1970s to a population estimate of 87 in the fall of 2009. We examined the available historical information to determine why caribou have declined. We compared three main hypotheses for caribou decline in JNP: human disturbance, climate change, and wildlife management. We used historical human use statistics, climate data, and animal abundance information to weigh the evidence for these competing hypotheses over two time scales. Caribou decline could not be attributed to changes in climate over the long-term, or an increase in human use (our proxy for disturbance). Caribou decline was attributed to a combination of climate and wildlife management. Recovery of caribou in Jasper National Park will likely be contingent on managing the interaction between the predator/prey dynamic and climate change. [ABSTRACT FROM AUTHOR]

Delineating demographic structure across an organism's range can reveal the extent to which population dynamics in different geographic areas are driven by local or external factors and can be crucial for effective conservation and management. Obtaining optimal data for such analyses can be time and resource-intensive and impending development and resource extraction pressures may necessitate the examination of existing data, even when they are less than ideal. We analyzed a historic telemetry dataset containing satellite radio-collar locations of 73 forest-dwelling woodland caribou in northern Ontario to determine demographic structure. We applied several clustering methods (i.e., agglomerative, divisive and fuzzy k-means) to median seasonal locations. Results were used to distinguish demographic units and minimum convex polygons and fixed-kernel density estimates were used to delineate unit boundaries and core areas. For areas where sampling was considered representative of the distribution of caribou on the landscape, we assessed demographic distinctness by evaluating intra-individual variation in cluster membership, membership strength and distance between boundaries and core areas of adjacent units. The number and composition of clusters identified was similar among methods and caribou were grouped into 6 general clusters. The distinctions between the three clusters identified in the central portion of the province (i.e., Lac Seul, Wabakimi, Geraldton) and the two clusters identified in the eastern portion of the province (i.e., Cochrane and Cochrane-Quebec) were determined to represent demographic structuring. Additional distinctions in other areas (i.e., between The Red Lake and Lac Seul clusters in the west and between the central and eastern clusters) may just be artifacts of the original sampling effort. Amongst demographic units, there was no evidence of individual flexibility in cluster membership and average membership strength was very high. There was little to no overlap between boundaries and core areas of adjacent units, but distances between adjacent unit boundaries were relatively low. Additional sampling effort is needed to further delineate demographic structure in Ontario caribou. [ABSTRACT FROM AUTHOR]

We evaluated three methods of estimating population size of woodland caribou (boreal ecotype) on the Slate Islands in northern Ontario. Located on the north shore of Lake Superior, the Slate Islands provide a protected and closed population with very limited predator influence that is ideal for a comparison of survey methods. Our objective was to determine the costs and benefits of three population estimation techniques: (1) forward looking infrared (FLIR) technology to count the number of caribou on regular-spaced transects flown by fixed-wing aircraft; (2) observers to count the number of caribou seen or heard while walking random transects in the spring; and, (3) mark-recapture sampling of caribou pellets using DNA analysis. FLIR and the genetics 3-window approach gave much tighter confidence intervals but similar population estimates were found from all three techniques based on their overlapping confidence intervals. There are various costs and benefits to each technique that are discussed further. Understanding the costs and benefits of different population estimation techniques is necessary to develop cost-effective programs for inventorying and monitoring this threatened species not only on the Slate Islands but for other populations as well. [ABSTRACT FROM AUTHOR]

The range of Ontario's woodland caribou (Rangifer tarandus caribou) (forest-dwelling ecotype) has receded northward substantially over many decades, leading to its current Threatened designation. Ontario released its Caribou Conservation Plan (CCP) in the fall of 2009. This policy responded to public input and recommendations from the Ontario Woodland Caribou Recovery Team and the Caribou Science Review Panel, and outlines conservation and recovery actions to conserve and recover caribou. Within an adaptive management framework, the CCP builds upon a recent history of managing at large landscape scales in Ontario to implement a range management approach as the basis for recovery actions. These commitments and actions include enhanced research and monitoring, improved caribou habitat planning at the landscape scale, an integrated range analysis approach using advanced assessment tools to evaluate thresholds of habitat amount, arrangement and disturbance, the assessment of probability of persistence, consideration of cumulative effects, meeting forest management silvicultural performance requirements, consideration of caribou recovery implications when managing other wildlife, an initial focus on the southern edge of caribou distribution where threats are most significant, improved outreach and stewardship, and consideration of Aboriginal Traditional Knowledge in recovery actions. Implementation of the CCP signifies a long-term provincial commitment to caribou recovery, initially focusing on identified priorities within the CCP. [ABSTRACT FROM AUTHOR]

Individual-based clustering (IBC) methods have become increasingly popular for the characterization and delineation of genetic population units for numerous species. These methods delineate populations based on the genetic assumptions of a breeding unit which may provide a better representation of the behaviour of the species. The increasing use of IBC has resulted in the development of several analytical models all of which vary in their theoretical assumptions to infer genetic population structure. In this paper, we report a comparative strategy utilizing three IBC methods to characterize the spatial genetic structure of the boreal population of woodland caribou ( Rangifer tarandus caribou) in central Canada. In addition, we implement both tests for isolation-by-distance (IBD) and frequency-based assignment tests to validate the consensus genetic clusters as defined by IBC. We also compare indirect metrics of genetic diversity and gene flow using both a priori defined herds and the IBC defined populations. Although our results show some concordance between both pre-defined herds and IBC derived genetic clusters, the IBC analyses identified a cluster that was cryptic to observation-based caribou herds and found no difference between several adjacent herds. By comparing multiple IBC methods and integrating both IBD and indirect genetic diversity metrics a posteriori, our strategy provides an effective means to delineate wildlife population structure and accurately assess genetic diversity and connectivity. [ABSTRACT FROM AUTHOR]

Allee effects can have significant consequences for small populations and understanding the causal mechanisms for such effects is important for guiding conservation actions. One proposed mechanism is through predation, in which a type II functional response leads to increasing predation rates as prey numbers decline. However, models to support this mechanism have incorporated only a single declining prey species in the functional response, which is probably an oversimplification. We reevaluated the potential for predator-mediated Allee effects in a multi-prey system using Holling's disc equation. We also used empirical data on a large herbivore to examine how grouping behavior may influence the potential for predation-mediated Allee effects. Results based on a multi-prey expression of the functional response predict that Allee effects caused by predation on relatively rare secondary prey may not occur because handling time of the abundant prey dominates the functional response such that secondary prey are largely "bycatch." However, a predator-mediated Allee effect can occur if secondary prey live in groups and if, as the population declines, their average group size declines (a relationship seen in several species). In such a case, the rate at which the number of groups declines is less than the rate at which the population declines. Thus the rate at which a predator encounters a group remains relatively stable, but when a predator kills one animal from smaller groups, the predation rate increases. These results highlight the need to evaluate risks associated with potential changes in group size as populations decline. [ABSTRACT FROM AUTHOR]

1. Accurate resource selection functions (RSFs) are important for managing animal populations. Developing RSFs using data from GPS telemetry can be problematic due to serial autocorrelation, but modern analytical techniques can help to compensate for this correlation. 2. We used telemetry locations from 18 woodland caribou Rangifer tarandus caribou in Saskatchewan, Canada, to compare marginal (population-specific) generalized estimating equations (GEEs), and conditional (subject-specific) generalized linear mixed-effects models (GLMMs), for developing resource selection functions at two spatial scales. We evaluated the use of empirical standard errors, which are robust to misspecification of the correlation structure. We compared these approaches with destructive sampling. 3. Statistical significance was strongly influenced by the use of empirical vs. model-based standard errors, and marginal (GEE) and conditional (GLMM) results differed. Destructive sampling reduced apparent habitat selection. k-fold cross-validation results differed for GEE and GLMM, as it must be applied differently for each model. 4. Synthesis and applications. Due to their different interpretations, marginal models (e.g. generalized estimating equations, GEEs) may be better for landscape and population management, while conditional models (e.g. generalized linear mixed-effects models, GLMMs) may be better for management of endangered species and individuals. Destructive sampling may lead to inaccurate resource selection functions (RSFs), but GEEs and GLMMs can be used for developing RSFs when used with empirical standard errors. [ABSTRACT FROM AUTHOR]

Abstract: Habitat alteration caused by forest harvesting seems to contribute to the decline of forest-dwelling caribou, an ecotype of woodland caribou (Rangifer tarandus caribou) inhabiting the boreal ecosystem. To serve as basework to the establishment of conservation measures for the species, we have studied the hierarchical habitat selection of forest-dwelling caribou in a boreal landscape of Québec strongly impacted by logging. Fifteen females were surveyed by GPS telemetry between April 2004 and March 2006. Home ranges showed a high proportion of 90–120 year-old forests, a low proportion of regenerating forests (20–40 years old) and a tendency to include a greater proportion of 6–20 year-old clearcuts in relation to their availability in the study area. At the home range scale, selection patterns differed between periods, possibly reflecting specific requirements linked to caribou life cycle. Caribou selected open lichen woodlands throughout the year while mature closed forests (≥50 years) were selected uniquely during summer. The 6–20 year-old clearcuts were avoided during calving, in summer and during the rutting period but were selected during spring. Our results indicate that mature forest and open lichen woodlands are highly selected forest cover types by caribou at both spatial scales. Although clearcuts were generally avoided at the home range scale, such avoidance was not observed at the larger scale, the search for 90–120 year-old forests being hampered by a uniform distribution of clearcuts. An a posteriori landscape analysis highlighted the spatial association between 6–20 year-old clearcuts and 90–120 year-old forests, an association that can be explained by the current regulations used in Québec. Our results underline the importance of pursuing research concerning the impact of such an exploitation regime on the long-term maintenance of the forest caribou in the boreal landscape. [Copyright &y& Elsevier]

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. • Policy decisions require strong cause-effect inferences to predict success of interventions. • Causal inferences about woodland caribou declines are constrained by observational data. • Causal modelling improves inferences for policy decisions in fields similarly constrained. • Policy interventions to arrest caribou declines can benefit from insights from causal modelling. [ABSTRACT FROM AUTHOR]

We investigated whether woodland caribou (Rangifer tarandus caribou) would remain in a 2772 km2 area in eastern Quebec where the forest management plan included the preservation of large forest blocks (35–182 km2) linked with >400 m wide corridors and where cuts were amalgamated in large zones. To evaluate changes in caribou abundance and habitat selection, we conducted five aerial surveys and followed by telemetry 13 to 22 female caribou each year, from March 1998 to March 2005. Caribou numbers declined by 59% between 1999 and 2001 but gradually recovered to initial abundance. Female survival increased from 73.3% in 1999 to 87.3%–93.4% in 2004 and 2005. Caribou selected protected blocks, used corridors in proportion to their availability, and avoided logged areas. They preferred closed conifer stands without terrestrial lichens and open conifer stands with or without terrestrial lichens throughout the study. Open habitats (clearcuts and burns), regenerating sites, mixed and deciduous stands, and water bodies were avoided. The main zones used by caribou gradually shifted towards the southwest of the study area, likely as a result of disturbance and habitat loss due to logging of mature conifers in the east. We conclude that caribou numbers were maintained within the managed area as a result of the presence of protected blocks and uncut continuous forest. [ABSTRACT FROM AUTHOR]

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

Wood bison (Bison bison athabascae Rhoads, 1898) were reintroduced to the Aishihik Lake area in the southwestern Yukon, where a population of woodland caribou (Rangifer tarandus caribou (Gmelin, 1788)) existed. These species co-occurred in nearby Beringia over several hundred thousand years and in the study area throughout most of the Holocene. We hypothesized that resource-selection patterns should differ widely between species at all scales because co-evolution should have resulted in strong patterns of resource partitioning. We compared winter utilization distributions of both species based on aerial survey data and assessed differential resource selection at the scales of landscape and distributional overlap. We also assessed differential resource use within feeding sites and compared late-winter diets of the two species. We found 41% overlap in 95% utilization distributions but only 6% overlap in 50% utilization distributions. Strong differences were measured for use of space and terrain, including elevation, slope, and distance from permanent water bodies. Bison strongly selected for or used graminoids, while caribou selected for or used lichens at each scale. Overlap in winter diet between the two species was 10%. At current densities, exploitative competition in winter between these species is unlikely. [ABSTRACT FROM AUTHOR]

Accurate and precise population estimates for the forest-dwelling ecotype of Woodland Caribou (Rangifer tarandus caribou) are very difficult to obtain because these Caribou are found at very low densities and in small herds dispersed over large areas. In order to suggest a standardized method, data from aerial surveys conducted in 1991 and 1993 (12 000 Km2 blocks) were used to simulate various survey scenarios. Simulations showed that all the major groups of Caribou would have to be found and counted to obtain a confidence interval of ± 20% (α = 0.10). We tested this technique in a survey carried out in winter 1999 in a 42 539 Km2 study site, opting for a total coverage carried out in two phases. In phase one, we used an airplane, flying north-south transects spaced 2.1 km apart so as to detect most Caribou track networks. In phase two, a helicopter was used to count and determine the sex and age classes (calves/adults) of Caribou found in phase one. Using 20 radio-collared Caribou, the visibility rate of Caribou groups (phase one) and that of Caribou within the groups (phase two) were estimated at 0.90 and 0.94 respectively for an overall rate of 0.85 (SE = 0.08; α = 0.10). The corrected density was estimated at 1.6 Caribou per 100 Km2 with a 15% confidence interval (α = 0.10). The survey cost approximately $4/Km2, which is lower than that of two previous surveys ($7/Km2). Two main factors contributed to diminish costs: (1) the use of long-range airplanes (5-7 hours flying range) in phase one to minimize travel between the airports and the study site, and (2) the use of helicopters only in phase two for counting and determining the age and sex of the Caribou. [ABSTRACT FROM AUTHOR]

Examines the habitat selection and demography of woodland carbou population in Newfoundland. Effect of interaction among human-induced habitat selection; Impact of black bear predation; Pregnancy and recruitment rates; Potential causes of mortality.

Linear developments such as roads, seismic lines, and pipeline rights-of-way are common anthropogenic features in the boreal forest of Alberta. These features may act as barriers to the movement of threatened woodland caribou, Rangifer tarandus caribou. Seismic lines were not barriers to caribou movements, whereas roads with moderate vehicle traffic acted as semipermeable barriers to caribou movements. Twenty-two adult female and 1 adult male woodland caribou were captured and collared on February 17–19, 1998. Each caribou was fitted with a global positioning system collar. The greatest barrier effects were evident during late winter, when caribou crossed actual roads 6 times less frequently than simulated road networks. Semipermeable barrier effects may exacerbate functional habitat loss demonstrated through avoidance behavior. Caribou may cross roads less frequently than expected for a number of reasons, including an aversion to the physical barrier presented by a road and associated forest opening, vehicle traffic, or predation by humans. The effects of habitat fragmentation through habitat loss, avoidance, and the semipermeable barrier effects of roads should be considered in developing strategies to maintain woodland caribou populations in Alberta. Roads that act as semipermeable barriers to caribou movements may make the presence of caribou more predictable in space and time, and hence compromise the "spacing out" strategy that caribou adopt to reduce predation. The approach we have outlined in this paper is a useful method to quantify the effects of human developments acting as semipermeable barriers to animal movements and should be considered in the development of animal-movement models.

We employed satellite-telemetry data to examine seasonal movement rates, annual- and seasonal-range sizes, and season-to-season range fidelity of female woodland caribou (Rangifer tarandus caribou) from five populations in the boreal forest of Saskatchewan. The populations studied are limited by predation, and we investigated whether female caribou exhibited movement and range use consistent with predator avoidance. Additionally, we document an animal-centred technique for assessing site fidelity on the basis of individual range use throughout a year. Females accompanied by calves had lower movement rates and smaller seasonal ranges than females without calves. Movement rates among female caribou tended to decline between the rut and the postcalving and summer seasons. Trends indicated that seasonal ranges were larger prior to calving than during the postcalving and summer seasons. We interpreted the range sizes and movement rates observed as being consistent with predator avoidance in nonmigratory caribou populations. Despite these results and high rates of calf mortality in the area, we did not find interannual fidelity to calving sites.Nous nous sommes servis de données de télémétrie par satellite pour étudier les taux des déplacements saisonniers, la taille des domaines annuels et saisonniers et la fidélité à un domaine chez des femelles du Caribou des bois (Rangifer tarandus caribou) de cinq populations dans la forêt boréale de la Saskatchewan. Les populations étudiées sont limitées par la prédation et nous avons examiné si les déplacements et les domaines des femelles peuvent être reliés à leur évitement des prédateurs. De plus, nous décrivons une technique centrée sur les animaux pour évaluer leur fidélité à un site d'après l'utilisation de leur domaine pendant toute l'année. Les femelles accompagnées de petits ont des taux de déplacement plus faibles et leurs domaines saisonniers sont plus petits que ceux des femelles sans petits. Les taux de déplacement chez les femelles ont tendance à décliner entre le rut et la période qui suit la mise bas et durant l'été. Les tendances indiquent que les domaines saisonniers sont plus grands avant la mise bas que durant la période qui suit et durant l'été. Nous interprétons les dimensions des domaines et les taux de déplacement observés comme des stratégies d'évitement des prédateurs chez les populations non migratrices de caribous. Malgré ces résultats et malgré les taux de mortalité élevés des petits dans la région, nous n'avons pas constaté de fidélité aux sites de mise bas d'une année à l'autre.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Some researchers have suggested that over periods of several decades, Arctic tundra caribou (Rangifer tarandus) may be regulated by density-dependent forage depletion. Winter range shifts could potentially delay such regulation when a population is at or near long-term maximum abundance. In the 1980s, Inuit correctly predicted the mass emigration of caribou from a traditional winter range on Foxe Peninsula (FP) on southern Baffin Island, Nunavut, Canada. Most FP caribou subsequently emigrated to a new winter range on Meta Incognita Peninsula (MIP). To determine if MIP provided emigrating caribou with better foraging habitats, we compared winter forage resources and snow cover at caribou foraging sites, and food selection by caribou on FP and MIP in April 1992. Caribou that remained on FP dug feeding craters in shallower, softer snow than those on MIP did. Biomass of most fruticose lichens was greater within foraging sites on MIP than on FP. Biomass of shrubs, other than Cassiope tetragona and Dryas integrifolia, was also greater on MIP than on FP. Dryas integrifolia was the only plant class that had higher biomass on FP than on MIP.Cladina spp. / Cladonia spp., Sphaerophorus fragilis, and Cetraria nivalis occurred less frequently in the rumens of FP caribou. Proportions of fruticose lichens in rumens of caribou on both peninsulas were similar to those on other overgrazed and High Arctic tundra winter ranges. Caribou on FP showed a higher preference for the shrub C. tetragona. Biomasses of plants sensitive to long-term feeding or trampling by caribou (i.e., the five most common fruticose lichens, other shrubs, and plant debris) were consistently lower on FP, which is congruous with Inuit reports that long-term cumulative overgrazing had reduced the supply of important forage plants on FP sites that were accessible to caribou in winter. FP caribou that emigrated to MIP gained access to more abundant, higher quality forage resources than those that remained on FP. Because most FP caribou had emigrated, this South Baffin subpopulation escaped, at least temporarily, the regulating effects of historical cumulative overgrazing.Des chercheurs croient que, sur une période de plusieurs décennies, les populations de caribous de la toundra arctique (Rangifer tarandus) peuvent être contrôlées par un épuisement du brout dépendant de la densité. Des changements d'aires d'hiver peuvent retarder ce contrôle quand une population a atteint ou est près d'atteindre son abondance maximale à long terme. Au cours des années 1980, les Inuits avaient prédit l'émigration en masse des caribous de leur aire traditionnelle d'hiver dans la péninsule Foxe (FP), dans le sud de la terre de Baffin, Nunavut, Canada. La plupart des caribous FP ont émigré vers une nouvelle aire d'hiver dans la péninsule de Meta Incognita (MIP). Dans le but de déterminer si la nouvelle aire contenait de meilleurs habitats pour l'alimentation des caribous émigrés, nous avons comparé les ressources de brout d'hiver, la couche de neige aux sites d'alimentation et le choix des aliments chez les caribous FP et MIP en avril 1992. Les caribous qui sont restés dans la FP se creusaient des trous d'alimentation moins profonds, dans de la neige plus molle, que les caribous MIP. La biomasse des lichens fruticuleux était plus élevée aux sites d'alimentation de la MIP que de la FP. La biomasse des buissons autres que Cassiope tetragona et Dryas integrifolia était aussi plus élevée dans la MIP que dans la FP. Dryas integrifolia s'est avérée la seule classe de plantes à avoir une biomasse plus grande dans la FP que dans la MIP.Cladina spp. / Cladonia spp., Sphaerophorus fragilis, et Cetraria nivalis ont été trouvés moins fréquemment dans les rumens des caribous FP. La proportion de lichens fruticuleux dans les rumens des caribous des deux péninsules était semblable à celle qu'on retrouve ailleurs dans les aires d'hiver des caribous de la toundra du haut Arctique qui sont broutées à l'excès. Les caribous FP ont montré une préférence plus grande pour la plante buissonneuse C. tetragona que les caribous MIP. La biomasse des plantes peu résistantes au broutage et au piétinement à long terme des caribous (i.e., les cinq lichens fruticuleux les plus communs, autres buissons et débris de plantes) était toujours moins élevée dans la FP, ce qui corrobore les dires des Inuits à l'effet que le broutage excessif cumulatif a réduit substantiellement la quantité de plantes importantes broutées par les caribous en hiver dans la FP. Les caribous FP qui ont émigré dans la MIP ont acquis l'accès à un brout plus abondant et de meilleure qualité que celui de la FP. Comme la plupart des caribous FP ont émigré, cette population de caribous du sud de la Terre de Baffin a échappé, du moins temporairement, aux effets cumulatifs du broutage excessif qui assurent habituellement le contrôle de cette population.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

Habitat selection is a hierarchical process that may yield various patterns depending on the scales of investigation. We employed satellite radio-telemetry to examine patterns of habitat selection by femalewoodland caribou in central Saskatchewan at both coarse (seasonal range) and fine (daily area) scales. At each scale, we converted spatial data describing compositions of available and used habitat to standardised resource selection indices and examined them with multivariate analyses of variance. Seasonal ranges generally showed preferentialinclusion of peatlands and black spruce dominated stands relative torecently disturbed stands and early seral stage forests. In all populations, caribou preferred peatlands and black spruce forests to all other habitat types at the daily area scale. In general, these patterns may reveal the effective avoidance of wolves, the primary factor limiting caribou throughout the boreal forest. In three populations where seasonal ranges showed the selective inclusion of either young jack pine stands or clearcuts along with peatlands and black spruce forests, we found a relative avoidance of the clearcuts and young jack pine stands at the daily area scale. As all caribou populations in thearea are thought to be relics of a once more continuous distribution, the seasonal range selection by animals in disturbed areas may better describe historic rather than current habitat selection. We found inter-annual variation in selection at the coarser spatial scale in one population, and inter-seasonal variation in selection at the finerspatial scale in three populations, indicating that the relative grains of the spatial and temporal scales coincide. We were better able to explain the seasonal variations in finer scale selection by considering available forage, a factor less likely than predation to limit woodland caribou populations. The data agree with the theory that thespatial and temporal hierarchy of habitat selection reflects the hierarchy [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Hypothesizes about the causes of decline of woodland caribou in Red Wine Mountains in central Labrador, Newfoundland particularly the effect of gray wolf predation to the population. Changes in mean age, sex ratio, and rates of recruitment, mortality and emigration of caribou; Implications of higher densities of moose and migratory caribou.

Presents information on a study which evaluates the properties of the Petersen mark-resight technique for estimating the population size of six woodland caribou herds in Newfoundland. Study area; Methods used; Results and discussion; Management implications.

Examines the effects of fire on the Aikens Lake population of woodland caribou in Manitoba. Evaluation of quality, quantity and accessibility of forages within the area; Estimation of forage accessibility through the Värriö Snow Index; Results of a principal components analysis regarding plant species distinctions that may have persisted after a fire; Discussion of the statistical findings of the study.