Investigations Into Premature Rock Bolt Failures in the Australian Coal Mining Industry

An ACARP project was initiated in 1999 to address the observed phenomenon of premature failure of rock bolts in a number of Australian coal mines, and with a particular focus on the problem of Stress Corrosion Cracking (SCC) in rock bolts. This paper briefly outlines the findings of this study

Lines on a map: conservation units, meta-population dynamics, and recovery of woodland caribou in Canada

Delineating conservation units is a fundamental step in recovery planning for endangered species. Yet, challenges remain in the application and validation of scientifically evaluated conservation units in management practice. The Canadian government makes use of Designatable Units (DUs) as the primary conservation unit under their Species‐at‐Risk Act. DUs must be ecologically discrete and have demonstrated evolutionary significance, which, in the case of woodland caribou (Rangifer tarandus caribou), has led to the definition of multiple DUs across Canada. Simultaneously, Environment and Climate Change Canada has released two recovery strategies affecting four DUs, wherein DUs are subdivided into smaller conservation units. However, the two recovery strategies adopt different definitions for the conservation unit. For the Boreal DU, the Local Population is considered the conservation unit for recovery management, whereas for Southern Mountain DU, the conservation unit for recovery is the subpopulation, which may or may not be comprised of several Local Populations. The scientific rationale for the difference between recovery strategies is unclear, not necessarily supported by genetic or demographic evidence, and highlights a policy challenge facing caribou conservation. We argue that the current emphasis on protecting subpopulations within a DU might be inconsistent and unviable for recovery planning. Instead, the recognition and emphasis on maintaining meta‐population dynamics within DUs is essential and currently underutilized in the long‐term recovery of woodland caribou in Canada

Consequences of a Refuge for the Predator-Prey Dynamics of a Wolf-Elk System in Banff National Park, Alberta, Canada

Refugia can affect predator-prey dynamics via movements between refuge and non-refuge areas. We examine the influence of a refuge on population dynamics in a large mammal predator-prey system. Wolves (Canis lupus) have recolonized much of their former range in North America, and as a result, ungulate prey have exploited refugia to reduce predation risk with unknown impacts on wolf-prey dynamics. We examined the influence of a refuge on elk (Cervus elaphus) and wolf population dynamics in Banff National Park. Elk occupy the Banff townsite with little predation, whereas elk in the adjoining Bow Valley experience higher wolf predation. The Banff refuge may influence Bow Valley predator-prey dynamics through source-sink movements. To test this hypothesis, we used 26 years of wolf and elk population counts and the Delayed Rejection Adaptive Metropolis Markov chain Monte Carlo method to fit five predator-prey models: 1) with no source-sink movements, 2) with elk density-dependent dispersal from the refuge to the non-refuge, 3) with elk predation risk avoidance movements from the non-refuge to the refuge, 4) with differential movement rates between refuge and non-refuge, and 5) with short-term, source-sink wolf movements. Model 1 provided the best fit of the data, as measured by Akaike Information Criterion (AIC). In the top model, Banff and Bow Valley elk had median growth rates of 0.08 and 0.03 (95% credibility intervals [CIs]: 0.027–0.186 and 0.001–0.143), respectively, Banff had a median carrying capacity of 630 elk (95% CI: 471.9– 2676.9), Bow Valley elk had a median wolf encounter rate of 0.02 (95% CI: 0.013–0.030), and wolves had a median death rate of 0.23 (95% CI: 0.146–0.335) and a median conversion efficiency of 0.07 (95% CI: 0.031–0.124). We found little evidence for potential source-sink movements influencing the predator-prey dynamics of this system. This result suggests that the refuge was isolated from the non-refuge

Linking Landscape-Scale Differences in Forage to Ungulate Nutritional Ecology

Understanding how habitat and nutritional condition affect ungulate populations is necessary for informing management, particularly in areas experiencing carnivore recovery and declining ungulate population trends.  Variations in forage species availability, plant phenological stage, and the abundance of forage make it challenging to understand landscape-level effects of nutrition on ungulates.  We developed an integrated spatial modeling approach to estimate landscape-level elk (Cervus elaphus) forage quality in two adjacent study areas that differed in coarse measures of habitat quality and related the consequences of differences in forage quality to elk body condition and pregnancy rates.  We found no support for differences in dry matter digestibility between plant samples or in phenological stage based on ground sampling plots in the two study areas.  Forage quality, measured as digestible forage biomass, varied among land cover types and between study areas. We found that altered plant composition following fires was the biggest driver of forage quality differences, suggesting that maintaining a mosaic of fire history and distribution will likely benefit ungulate populations.  Study area, lactation status and year affected fall body fat of adult female elk.  Elk in the study area exposed to lower quality summer range forage had lower nutritional condition entering winter.  These differences in nutritional condition resulted in differences in pregnancy rate, with average pregnancy rates of 89% for elk exposed to higher quality forage and 72% for elk exposed to lower quality forage.  Summer range forage quality has the potential to limit elk pregnancy rate and calf production, and these nutritional limitations may predispose elk to be more sensitive to the effects of harvest or predation.  Wildlife managers should identify ungulate populations that are nutritionally limited and recognize that these populations may be more impacted by recovering carnivores or harvest than populations inhabiting more productive summer habitats

Evaluating risk effects of industrial features on woodland caribou habitat selection in west central Alberta using agent-based modelling

AbstractAlberta 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

Human Influences on Elk Movement Rates and Resource Selection in the Wildland-Urban Interface.

Elk (Cervus elaphus) are known to select for refuge from hunting by humans (elk hunting). In many areas in the western U.S., elk hunting is completely excluded in the wildland-urban interface (WUI) as a result of land ownership change and subdivision, thus providing refugia for elk. Many of these WUI elk populations are increasing rapidly, and pose a significant credibility challenge to wildlife managers. The North Hills Elk Herd, in Missoula, Montana, has been growing at ~11 percent since the early 1980s, and the herd now numbers over 300 animals. Landownership is a complex matrix of public and private lands that range from partial to complete exclusion of hunting, thus elk hunting pressure is low and provides multiple refugia. Montana Fish, Wildlife and Parks used elk hunting in this setting to reduce population growth, crop depredation, and habituation. Little is known about the efficacy of elk hunting on elk movement rates and habitat selection. We used First-Passage Time (FPT) and Resource Selection Functions (RSF) analysis based on nine GPS collared adult female elk during three hunting seasons with increasing hunting pressure (2007-2009) to test relationships between elk movement rates and resource selection in the WUI. Elk FPT decreased annually, if they were accessible, and differed by hunting mode and season. Elk selected for intermediate distances from homes, trails, and weakly avoided access. These data have been used to modify hunting season structure, acquire conservation easements, and develop lasting partnerships in a complex matrix of ownerships

Assessing Integrated Carnivore-Ungulate Management in the Bitterroot Valley

Whether increasing large carnivore harvest can increase ungulate populations is uncertain for several reasons. One primary ecological uncertainty is whether carnivores limit ungulate population dynamics. A second results from partial controllability of large carnivore populations; whether large carnivore hunting seasons will reduce carnivores to the extent that ungulates increase.  We first review cases of ‘integrated carnivore-ungulate’ management from western North America, highlighting where key uncertainties were addressed.  Then, using the Bitterroot valley of MT as a case study, we present results from a research project designed to provide quantitative measurements of (1) elk population dynamics and limiting factors, (2) mountain lion densities, (3) the effect of harvest on mountain lion densities under a management plan designed to differentially affect lion density across western Montana, and (4) the ultimate effect of changes in mountain lion seasons on elk population dynamics. During the first phase of research, mountain lions caused 6-8 times more mortality than wolves, limiting elk populations via calf survival and recruitment. We estimated mountain lion densities in the Bitterroot and Granite County to help address scientific uncertainty, the effect of lion hunting on lion densities and ultimately elk recruitment and populations. In 2016, following implementation of 4 years of mountain lion seasons intended to reduce lion density in the Bitterroot and stabilize lion density in Granite county, we plan to return to the Bitterroot to monitor both lion and ungulate populations to quantify the effects of this integrated carnivore-elk management strategy. This research will provide objective information to inform public decision-making processes about carnivore and elk management, but it cannot provide direction regarding what strategy for carnivore or elk management should be pursued. Balancing the input and desires of divergent stakeholders is perhaps the most challenging facet surrounding integrated carnivore-elk management

Evaluating Bottom-Up and Top-Down Effects on Elk Survival and Recruitment: A Case Study in the Bitterroot Valley

Understanding the contribution of recruitment rates to overall growth rate in ungulate populations is a fundamental challenge in wildlife management. Ungulate populations with low recruitment rates may result in population level declines over time. In the southern Bitterroot Valley of western Montana, the decline of elk (Cervus elaphus) populations and calf recruitment occurred concurrently with wolf (Canis lupus) recovery. However, a multitude of abiotic, bottom-up and top-down factors likely affect recruitment rates and the relative affects of these factors on elk calf survival rate likely vary temporally throughout the first year. We studied cause-specific mortality of elk calves to understand the role of competing mortality risk on calf recruitment in the East Fork and West Fork of the Bitterroot Valley, Montana. A total of 66 neonatal elk calves were captured in spring 2011 and an additional 31 6-month olds in late November2011. We will analyze survival using a Weibull parametric survival model, and cause-specific mortality using a competing risks framework. Preliminary analyses suggest the potential for competing risks between black bears, mountain lions, and wolves. As the study progresses into the second year, we will evaluate the role of summer range nutritional resources on maternal condition, lactation performance, and calf birth weights and survival. Our study will fill a gap regarding the role of summer vs winter mortality in elk and the role of nutrition in first year survival. The study will complement previous studies on elk population dynamics and inform elk population management following carnivore recovery

A Multi-Scale Test of the Forage Maturation Hypothesis in a Partially Migratory Ungulate Population

The forage maturation hypothesis (FMH) proposes that ungulate migration is driven by selection for high forage quality. Because quality declines with plant maturation, but intake declines at low biomass, ungulates are predicted to select for intermediate forage biomass to maximize energy intake by following phenological gradients during the growing season. We tested the FMH in the Canadian Rocky Mountains by comparing forage availability and selection by both migrant and nonmigratory resident elk (Cervus elaphus) during three growing seasons from 2002-2004. First, we confirmed that the expected trade-off between forage quality and quantity occurred across vegetation communities. Next, we modeled forage biomass and phenology during the growing season by combining ground and remote-sensing approaches. The growing season started 2.2 days earlier every 1 km east of the continental divide, was delayed by 50 days for every 1000-m increase in elevation, and occurred 8 days earlier on south aspects. Migrant and resident selection for forage biomass was then compared across three spatial scales (across the study area, within summer home ranges, and along movement paths) using VHF and GPS telemetry locations from 119 female elk. Migrant home ranges occurred closer to the continental divide in areas of higher topographical diversity, resulting in migrants consistently selecting for intermediate biomass at the two largest scales, but not at the. nest scale along movement paths. In contrast, residents selected maximum forage biomass across all spatial scales. To evaluate the consequences of selection, we compared exposure at telemetry locations of migrant and resident elk to expected forage biomass and digestibility. The expected digestibility for migrant elk in summer was 6.5% higher than for residents, which was corroborated with higher fecal nitrogen levels for migrants. The observed differences in digestibility should increase migrant elk body mass, pregnancy rates, and adult and calf survival rates. Whether bottom-up effects of improved forage quality are realized will ultimately depend on trade-offs between forage and predation. Nevertheless, this study provides comprehensive evidence that montane ungulate migration leads to greater access to higher-quality forage relative to nonmigratory congeners, as predicted by the forage maturation hypothesis, resulting primarily from large-scale selection patterns

The GPS craze: six questions to address before deciding to deploy GPS technology on wildlife

GPS and satellite technology for studies on wildlife have improved substantially over the past decade. It is now possible to collect fine-scale location data from migratory animals, animals that have previously been too small to deploy GPS devices on, and other difficult-to-study species. Often researchers and managers have formatted well-defined ecological or conservation questions prior to deploying GPS on animals, whereas other times it is arguably done simply because the technology is now available to do so. We review and discuss six important interrelated questions that should be addressed when planning a study requiring location data. Answers will clarify whether GPS technology is required and whether its use would increase efficiency of data collection and learning from location data. Specifically, what are required: (1) ecological question(s); (2) frequency and duration of data collection; (3) sample size; (4) hardware (VHF or GPS or satellite) and accessories; (5) environmental data; and (6) data-management and analysis procedures? This approach increases the chance that the appropriate technology will be deployed, budgets will be realistic, and data will be sufficient (but not excessive) to answer the ecological questions of interest. The expected results are important advances in ecological science and evidence-based management decisions