Search

Copyright of Canadian Geographer is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Species vary in their responses to urban habitat; most species avoid these environments, whereas others tolerate or even thrive in them. To better characterize the extent to which species vary in their responses to urban habitat (from this point forwards "urban tolerance"), we used several methods to quantify these responses at a continental scale across all birds. Using open access community science‐derived data from the eBird Status and Trends Products and two different types of high‐resolution geospatial data that quantify urbanization of landscapes, we calculated urban tolerance for 432 species with breeding ranges that overlap large cities in Canada or the USA. We developed six different calculations to characterize species‐level urban tolerance, allowing us to assess how each species' relative abundance across their breeding range varied with estimates of urban habitat use and intensity. We assessed correlations among these six indices, then compressed the two best‐performing indices into a single principal component (multivariate urban tolerance index) that captured variation in urban tolerance among species. We assessed the accuracy of our single and multivariate urban tolerance indices using 24 test species that have been well characterized for their tolerance or avoidance of the urban habitat, as well as with previously published, independent urban tolerance estimates. Here, we provide this new dataset of species‐level urban tolerance estimates that improves upon previous metrics by incorporating continental‐scale, continuous estimates that better differentiate species' tolerance of urban habitat compared with existing, categorical methods. These refined metrics can be used to test hypotheses that link ecological, life history, and behavioral traits to avian urban tolerance. The dataset is licensed as CC‐By Attribution 4.0 International. Users must appropriately cite the data paper and dataset if used in publications and scientific presentations. [ABSTRACT FROM AUTHOR]

The Elateridae, or click beetles are abundant and diverse in most terrestrial ecosystems in North America, acting as plant pests and filling many other ecological roles. The 112 genera of Elateridae Leach, 1815, or click beetles, known from Canada and USA are included in a first comprehensive digital interactive key to adults. A link to an online peer-reviewed LUCID key to elaterid genera and downloadable LUCID files are provided. Diagnostic morphological summaries using information from the 61 characters and 158 character states of the matrix key are presented for all genera. A table summarizes current understanding of habitat use by all elaterid genera in Canada and USA from literature, collections, citizen science, and our own observations. Diversity of elaterid genera was high throughout warm and cool temperate regions, especially in mountainous areas and mesic woodlands. Larvae of most genera were associated with soil, litter and decaying wood. [ABSTRACT FROM AUTHOR]

The southern extent of the range of Canada lynx (Lynx canadensis) extends into the contiguous United States in locations from Washington State in the West to northern Maine in the East. Lynx persist in various habitats across this range from high-elevation wilderness to intensively managed industrial forests. Lynx habitat use at the species' southern range boundary was poorly understood before the species was listed as Threatened under the Endangered Species Act in 2000, because most research had been conducted in boreal forest. The papers in this special section outline a variety of questions regarding lynx populations at the southern extent of their range, address topics on lynx space use and denning habitat, and provide generally consistent results in terms of features important to lynx habitat use despite the wide variation in specific habitats among the study areas. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Feral populations of cultivated crops can pose challenges to novel trait confinement within agricultural landscapes. Simulation models can be helpful in investigating the underlying dynamics of feral populations and determining suitable management options. Methodology/Principal Findings: We developed a stage-structured matrix population model for roadside feral alfalfa populations occurring in southern Manitoba, Canada. The model accounted for the existence of density-dependence and recruitment subsidy in feral populations. We used the model to investigate the long-term dynamics of feral alfalfa populations, and to evaluate the effectiveness of simulated management strategies such as herbicide application and mowing in controlling feral alfalfa. Results suggest that alfalfa populations occurring in roadside habitats can be persistent and less likely to go extinct under current roadverge management scenarios. Management attempts focused on controlling adult plants alone can be counterproductive due to the presence of density-dependent effects. Targeted herbicide application, which can achieve complete control of seedlings, rosettes and established plants, will be an effective strategy, but the seedbank population may contribute to new recruits. In regions where roadside mowing is regularly practiced, devising a timely mowing strategy (early- to mid-August for southern Manitoba), one that can totally prevent seed production, will be a feasible option for managing feral alfalfa populations. Conclusions/Significance: Feral alfalfa populations can be persistent in roadside habitats. Timely mowing or regular targeted herbicide application will be effective in managing feral alfalfa populations and limit feral-population-mediated gene flow in alfalfa. However, in the context of novel trait confinement, the extent to which feral alfalfa populations need to be managed will be dictated by the tolerance levels established by specific production systems for specific traits. The modelling framework outlined in this paper could be applied to other perennial herbaceous plants with similar life-history characteristics. [ABSTRACT FROM AUTHOR]

Background: One of the greatest obstacles to moving ecosystem-based management (EBM) from concept to practice is the lack of a systematic approach to defining ecosystem-level decision criteria, or reference points that trigger management action. Methodology/Principal Findings: To assist resource managers and policymakers in developing EBM decision criteria, we introduce a quantitative, transferable method for identifying utility thresholds. A utility threshold is the level of human-induced pressure (e.g., pollution) at which small changes produce substantial improvements toward the EBM goal of protecting an ecosystem's structural (e.g., diversity) and functional (e.g., resilience) attributes. The analytical approach is based on the detection of nonlinearities in relationships between ecosystem attributes and pressures. We illustrate the method with a hypothetical case study of (1) fishing and (2) nearshore habitat pressure using an empirically-validated marine ecosystem model for British Columbia, Canada, and derive numerical threshold values in terms of the density of two empirically-tractable indicator groups, sablefish and jellyfish. We also describe how to incorporate uncertainty into the estimation of utility thresholds and highlight their value in the context of understanding EBM trade-offs. Conclusions/Significance: For any policy scenario, an understanding of utility thresholds provides insight into the amount and type of management intervention required to make significant progress toward improved ecosystem structure and function. The approach outlined in this paper can be applied in the context of single or multiple human-induced pressures, to any marine, freshwater, or terrestrial ecosystem, and should facilitate more effective management. [ABSTRACT FROM AUTHOR]

1. Elevational gradients create environmental variation that is hypothesized to promote variation in life-history strategies. We tested whether differences in life-history strategies were associated with elevation in a songbird, the dark-eyed junco ( Junco hyemalis; Aves; A.O.U. 1998 ). 2. We monitored birds in four replicated sites per elevation, at 2000 m a.s.l. (high elevation) and 1000 m a.s.l. (low elevation), in the Rocky Mountains of Canada. 3. Over 5 years, we measured the following traits and vital rates: egg-laying schedules, morphological indicators of reproductive stage, seasonal reproductive success, indicators of competitive class (age, size, arrival time), and survival rates. 4. We found two main patterns: with an increase in breeding elevation, dark-eyed juncos delayed the development of structures necessary for reproduction (e.g. cloacal protuberance in males) and reduced the duration of their reproductive period to less than half of the time used by low-elevation birds; and 5. Juncos at high-elevation sites had 55–61% lower annual reproductive success and 15 to 20% higher survival rates. While adult juncos at high elevations produced fewer offspring, those offspring were in better condition. Proportions of age and size classes in high- compared to low-elevation populations were similar, suggesting that a life-history trade-off is present, rather than competition forcing inferior competitors to breed in a peripheral habitat. The apparent trade-off between reproduction and survival corresponded to a shorter period of favourable weather and available food in high- compared to low-elevation habitats. 6. Thus, elevation had a strong influence on life-history characteristics of a single species over a short spatial distance, suggesting a shift in life history from a high reproductive strategy at lower elevations to a high survivor strategy at high elevations. 7. This is the first paper to show a shift in avian life-history strategies along an elevational gradient (in both genders, of multiple age classes) when region (latitude) and phylogenetic histories are controlled for. [ABSTRACT FROM AUTHOR]

Physical ocean circulation features, especially the Gaspé Current (GC) intrusion, influence the transport and aggregation of whale prey, thereby influencing the whale foraging habitat in the Gulf of St. Lawrence (GSL), Canada. We employ satellite altimetry-derived sea level anomaly (SLA) indices to monitor interannual variations in the intensity of the GC in the North Atlantic Right Whale (Eubalaena glacialis; NARW) habitat in the GSL. Measurements of surface slope and volume transport are taken from the SLA profiles along a repeating ground track of the Jason-2/3 satellites. These are employed as complementary proxies in characterizations of physical processes in the GSL. The relationship between altimetric indices and indices of zooplankton abundance are explored in the southern GSL. Results demonstrate that an altimetric index estimated from surface slope (Index s l o p e − h a l f ) is correlated with river discharge of the St. Lawrence River and can be utilized to infer variations in GC intensities. Time series of the altimetric indices during 2009–2021 are found to exhibit interannual and seasonal environmental variability, which influence transport into the southern GSL. As captured by the altimetric indices, these features of the surface ocean circulation can be linked to zooplankton variations in the Shediac Valley, where NARWs are frequently observed. Therefore, in linking physical drivers of ocean dynamics to the NARW foraging habitat, variations in these indices can also potentially help describe some features of the distribution patterns of NARW sightings in this area. [ABSTRACT FROM AUTHOR]

Assessing wildlife habitat suitability has been an important tool in species conservation for generations of wildlife managers, despite changes in technology and theoretical frameworks. The goal of this study was to quantify differences in habitat suitability indices (HSIs) for blue-winged teal derived from our re-creation of traditional paper-based outputs and GIS-based outputs using the same inputs and to determine how HSIs for blue-winged teal would respond to fine-scale applications in Miquelon Lake Provincial Park, Canada. The subsequent models assessed the four original variables presented by the 1985 USFWS model: wetland density, wetland area, horizontal cover, and proximity to wetlands for three components of breeding habitat including pair bonding, nesting, and brood rearing. For a subset of GIS models, vertical cover was also incorporated into our analyses to determine its applicability in the model's assessment of aerial predation risk for blue-winged teal. The paper-based model consistently produced higher habitat suitability scores when compared to the GIS model, with only the brood-rearing model being slightly lower. When vertical cover was included in the GIS model either by itself or combined with horizontal cover, the area of high suitability habitat was reduced to 0% and ∼3%, respectively. Results revealed that the species did not show a special preference to high or moderately suitable habitats. Given the overestimation of habitat suitability at all breeding stages for blue-winged teal, the comparative utility of the actual HSI scores derived manually from such models are limited; however, the long-term ecological insights into model inputs are invaluable when integrated with emerging spatial data for computer-based habitat modelling. [ABSTRACT FROM AUTHOR]

Environmental impact assessments (EIAs) aim to assess the predicted effects of future projects on the environment, human health, and the economic potential of a region. They are an instrumental tool for sustainable development and to reduce the impact of large-scale industrial projects on biodiversity. The accurate assessment of the effects of projects on wildlife populations has a variety of ecological, cultural, and economic implications. However, assessments are commonly done using indirect indicators such as the predicted impact of changes in the quantity and quality of wildlife habitat and (or) predicted changes in nonspecific wildlife population metrics (e.g., relative abundance). In recent decades, the interpretation of wildlife health has moved from the classical dichotomous state of "disease presence/absence" to a broader concept that integrates the interaction of biological, social, and environmental health determinants. We sought to determine how wildlife health metrics are used in EIA processes and propose a framework to characterize, quantify, and monitor wildlife health in future EIAs. First, we performed a targeted review of EIA documents from three jurisdictions in Canada to characterize the relevance and use of "wildlife health" in these documents. Then, we reviewed case studies and research examples to understand wildlife health in different contexts associated with conservation biology to propose a framework to incorporate wildlife health into baseline monitoring and mitigation processes in EIAs. Our targeted review illustrates that while wildlife health and related terminology is often invoked in the main and specific objectives of EIAs, it is rarely tracked and quantified in EIAs and related processes. We identified approaches that can be used to effectively incorporate wildlife health in EIAs, including context-specific wildlife health metrics, participatory epidemiology, community-based sampling, and local ecological knowledge. We illustrate case studies where wildlife health can facilitate the inclusion of communities, Indigenous governments, and local ecological knowledge into the evaluation process of projects and developments and into comanagement practices of wildlife. Our work highlights the critical need to move towards incorporating wildlife health into EIA processes to provide a more direct and holistic perspective on the potential environmental impacts and improve the opportunities for early implementation of mitigation measurements. [ABSTRACT FROM AUTHOR]

Soil contains a diverse fauna and microflora that are vital for maintaining healthy soils and their various ecosystem services. Oribatid mites are typically highly abundant arthropods in the soil and are used as indicators for environmental monitoring. The aim of this study was to determine oribatid mite community response to natural land cover, anthropogenic disturbance, space, and climate in the oil sands region of Alberta, Canada. Our results found that oribatid mite total abundance was significantly reduced by mining, cultivation, and well sites. Species richness was significantly reduced by mining and cultivation. Shannon's diversity index was significantly higher for all natural land cover types, seismic lines, and forest harvest. Additionally, species diversity was lower under the relative influence of energy-related soft linear disturbances than for naturally vegetated sites and forest harvesting, and was lowered further by anthropogenic disturbances with more impact on soil integrity (cultivation, mines, urban/industrial, road/trail verges, well sites). Abundance, richness, and diversity also increased with increased frost free period and with eastward longitude. Mite community composition included a notable composition difference between lowland habitats and upland forest types, and between natural land cover and intense anthropogenic disturbance types (e.g., mines, cultivation). Our study highlighted oribatid mite communities' response to natural land cover, anthropogenic disturbance and spatial–climatic factors assessed over broad spatial scales and the potential utility of oribatid mites as ecosystem health indicators under multiple ecological drivers. [ABSTRACT FROM AUTHOR]

Most research on boreal populations of woodland caribou (Rangifer tarandus caribou) has been conducted in areas of high anthropogenic disturbance. However, a large portion of the species' range overlaps relatively pristine areas primarily affected by natural disturbances, such as wildfire. Climate‐driven habitat change is a key concern for the conservation of boreal‐dependent species, where management decisions have yet to consider knowledge from multiple ecological domains integrated into a cohesive and spatially explicit forecast of species‐specific habitat and demography. We used a novel ecological forecasting framework to provide climate‐sensitive projections of habitat and demography for five boreal caribou monitoring areas within the Northwest Territories (NWT), Canada, over 90 years. Importantly, we quantify uncertainty around forecasted mean values. Our results suggest habitat suitability may increase in central and southwest regions of the NWT's Taiga Plains ecozone but decrease in southern and northwestern regions driven by conversion of coniferous to deciduous forests. We do not project that boreal caribou population growth rates will change despite forecasted changes to habitat suitability. Our results emphasize the importance of efforts to protect and restore northern boreal caribou habitat despite climate uncertainty while highlighting expected spatial variations that are important considerations for local people who rely on them. An ability to reproduce previous work, and critical thought when incorporating sources of uncertainty, will be important to refine forecasts, derive management decisions, and improve conservation efficacy for northern species at risk. [ABSTRACT FROM AUTHOR]

Protecting habitat of species at risk is critical to their recovery, but can be contentious. For example, protecting species that are locally imperilled but globally common is often thought to distract from protecting globally imperilled species. However, such perceived trade-offs are based on the assumption that threatened groups have little spatial overlap, which is rarely quantified. We compiled range maps of terrestrial species at risk in Canada to assess the geographic overlap of nationally and globally at-risk species with each other, among taxonomic groups, and with protected areas. While many nationally at-risk taxa only occur in Canada at their northern range edge, they are not significantly more peripheral in Canada than globally at-risk species. Further, 56% of hotspots of nationally at-risk taxa are also hotspots of globally at-risk species, undercutting the perceived trade-off in their protection. While strong spatial overlap across threat levels and taxa should facilitate efficient habitat protection, less than 7% of the area in Canada's at-risk hotspots is protected, and two-thirds of nationally and globally at-risk species in Canada have less than 10% of their Canadian range protected. Our results counter the perception that protecting nationally versus globally at-risk species are at odds, and identify critical areas to target as Canada strives to increase its protected areas and promote recovery of species at risk. [ABSTRACT FROM AUTHOR]

Indigenous Peoples around the northern hemisphere have long relied on caribou for subsistence and for ceremonial and community purposes. Unfortunately, despite recovery efforts by federal and provincial agencies, caribou are currently in decline in many areas across Canada. In response to recent and dramatic declines of mountain caribou populations within their traditional territory, West Moberly First Nations and Saulteau First Nations (collectively, the "Nations") came together to create a new vision for caribou recovery on the lands they have long stewarded and shared. The Nations focused on the Klinse‐Za subpopulation, which had once encompassed so many caribou that West Moberly Elders remarked that they were "like bugs on the landscape." The Klinse‐Za caribou declined from ~250 in the 1990s to only 38 in 2013, rendering Indigenous harvest of caribou nonviable and infringing on treaty rights to a subsistence livelihood. In collaboration with many groups and governments, this Indigenous‐led conservation initiative paired short‐term population recovery actions, predator reduction and maternal penning, with long‐term habitat protection in an effort to create a self‐sustaining caribou population. Here, we review these recovery actions and the promising evidence that the abundance of Klinse‐Za caribou has more than doubled from 38 animals in 2013 to 101 in 2021, representing rapid population growth in response to recovery actions. With looming extirpation averted, the Nations focused efforts on securing a landmark conservation agreement in 2020 that protects caribou habitat over a 7986‐km2 area. The Agreement provides habitat protection for >85% of the Klinse‐Za subpopulation (up from only 1.8% protected pre‐conservation agreement) and affords moderate protection for neighboring caribou subpopulations (29%–47% of subpopulation areas, up from 0%–20%). This Indigenous‐led conservation initiative has set both the Indigenous and Canadian governments on the path to recover the Klinse‐Za subpopulation and reinstate a culturally meaningful caribou hunt. This effort highlights how Indigenous governance and leadership can be the catalyst needed to establish meaningful conservation actions, enhance endangered species recovery, and honor cultural connections to now imperiled wildlife. [ABSTRACT FROM AUTHOR]

Much of Canada's terrestrial biodiversity is supported by boreal forests. Natural resource development in boreal forests poses risks to this biodiversity. This paper reviews the scientific literature to assess the effects of natural resource development on terrestrial biodiversity in Canadian boreal forests. We address four questions: (1) To what extent have Canadian boreal forests changed due to natural resource development? (2) How has biodiversity responded to these changes? (3) Will the biodiversity of second-growth forests converge with that of primary boreal forests? (4) Are we losing species from boreal forests? We focus on trees, understory plants, insects, fungi, selected mammals, and songbirds because these groups have been most studied. We review more than 600 studies and found that changes in community composition are prevalent in response to large-scale conversion of forest types, changes in stand structures and age distributions, and altered landscape structure resulting from forest management and habitat loss associated with other developments such as oil and gas, hydroelectric, and mining. The southern boreal forest has been more highly impacted than the north due to more extensive forest management and the cumulative effects of multiple forms of development. There is abundant evidence that most species are not in danger of being extirpated from the boreal forest due to these anthropogenic changes. A few species, including woodland caribou ( Rangifer tarandus) and grizzly bear ( Ursus arctos), have, however, undergone long-term range contractions. Significant gaps in our ability to assess the effects of natural resource development on biodiversity in the boreal zone are the lack of long-term spatial and population data to monitor the impact of forest changes on ecosystems and species. [ABSTRACT FROM AUTHOR]

Abstract: Birds can be used as indicators to monitor success of programs encouraging prairie landowners to increase biodiversity. Using a case study from Alberta, Canada, this paper compares bird diversity measures at the farm scale and examines their consistency across different habitat types to test for design, output, and end use validation. Based on 2005 point count data (two types) from 178 sites at 22 farms, we calculated bird species richness, abundance, Shannon index, and Inverse Simpson index. The 50m radius data produced species richness and abundance measures about half the size as those produced by the unlimited radius data. The bird diversity measures were consistent across habitat types. The 50m radius data showed differences among 3–5 habitat types, whereas the unlimited radius data showed differences between only two habitat types. Using any bird diversity measure, the wetland/riparian habitat scored highest, followed by homestead, upland forest, native prairie, tame pasture, and cultivated land habitats. Bird monitoring methods should favor fixed over unlimited radius point counts, because of the former''s greater discriminating ability. Given that diversity measures are consistent across habitats and are highly correlated, the species richness measure, which is simple and easy to understand, can be used in conversations with landowners and policy-makers. [Copyright &y& Elsevier]

The article presents a study on the ecological habit of the Saint Lawrence River from Lake Ontario to the Atlantic Ocean at the Gulf of Saint Lawrence in Canada. The study aims to replace the existing ecology curriculum in the schools since it is a local resource and investigates the scientific issues in this resource. It notes that the study focused on muskellunge fish, water quality, and invasive species. It points out that the students reinforced their knowledge of ecology and offers an opportunity to see the real-life applications of what they learn.

In the Canadian Western Boreal Plain (WBP), wetlands (ponds and peatlands) comprise up to 50% of the landscape and represent unique habitat where summer precipitation is often outpaced by evapotranspiration and hillslope groundwater position does not follow topography. In this sub-humid location, groundwater fluxes and stores in riparian peatlands influence pond water levels and root zone moisture sources for forested uplands. To accurately describe the transport and retention of water in peat, it is important to consider peat subsidence. This paper quantifies the amount and effect of seasonal subsidence in a riparian peatland in the Utikuma Lake region in north-central Alberta, Canada. Results demonstrate that the deep and poorly decomposed peat deposits are resistant to compression, and that thick (and persistent) ground frost hinders pore collapse (shrinkage) above the water table until late summer when the ground has thawed. Even then, subsidence is still limited to the top 50 cm and is not closely related to changes in peatland water table or pond water level. Thus the water balance of these ponds and riparian areas appears to be less sensitive to peat volume changes than it is to the persistence of a substantial frost layer well into the snow-free period. [ABSTRACT FROM AUTHOR]

Moose (AIces alces)-vehicle collisions (MVC) can be costly ecologically by affecting population numbers, economically by vehicle damage, and socially through human injury or mortality. The purpose of this paper is to identify factors related to moose ecology, driver behaviour, and road design that are useful for predicting the spatial location of MVC on the Trans Canada Highway dissecting Mount Revelstoke and Glacier National Parks. We identified 6 subsets of logistic regression models and used Akaike's information Criteria (AIC) to determine the most parsimonious model within each subset. In addition to this study being the first to examine collisions within these 2 parks, each of these 6 modelling procedures is unique in predicting MVC. Five of the six subsets modelled local-scale/field-based hypotheses of driver visibility, moose evidence, highway design, roadside vegetation, and moose habitat, while the sixth subset examined landscape-scale hypotheses through the use of a Geographic Information System (GIS). The Receiver Operator Characteristic (ROC) discriminated between MVC and random reference sites in order to validate the best fit model from each of the 6 subsets. A MVC probability map along the highway was created using the GIS model, providing a powerful and relatively efficient and inexpensive planning tool. The moose evidence model correctly classified the most MVC among the local-scale models. In relation to the spatial analysis, highway planning to reduce MVC risk within the parks should begin by assessing landscape-scale variables with emphasis on distance to wetland and landscape slope. This landscape-scale analysis should be followed by field-based modelling using moose evidence and habitat-related modelling with important predictors of moose tracks, game trails, and coniferous forest habitat. If highway planning cannot be effective in decreasing MVC, mitigation measures should include a public awareness program, speed reduction, and consideration of an alternative intercept foraging plan. [ABSTRACT FROM AUTHOR]

Although the exceptional spatiotemporal extent of the Waterfowl Breeding Population and Habitat Survey (WBPHS) has substantially contributed to our understanding of the ecology of North American waterfowl, vast geographical areas remain excluded from the survey. The unprecedented number of observations generated by the recent boom in citizen science initiatives could help resolve these spatial gaps and increase the density of records in regions already covered. The study objective was to assess the value of the integrated species distribution modeling (ISDM) approach for integrating WBPHS and eBird data to model waterfowl distribution across the Canadian western boreal forest, where WBPHS data are sparse. Following the ISDM approach, we used a state‐space point process formulation that combined a model for the "true" species distribution and two observation models for how WBPHS and eBird data were generated. Our results highlighted the importance of observational processes related to sampling effort and site accessibility for modeling eBird data. In addition, our models allowed identifying waterfowl–habitat associations related to geoclimatic, forest, and hydrological factors that explained the distribution of target species. To assess the individual contribution of WBPHS and eBird data, we re‐fitted the models using only one of the two data sets and compared the results obtained against those from the integrated approach. Waterfowl–habitat associations and predictions derived from the models using both data sets and those fitted with WBPHS data only were close and consistent with the observed species distribution. However, it was more difficult to extract an ecological signal from models fitted with eBird data only. Interestingly, predictions from models combining both data sets were closer to the WBPHS records than the predictions from models fitted with WBPHS data only. By facilitating the combination of all available data sources, we demonstrated the potential of the ISDM approach for modeling and mapping species distributions. We encourage future North American waterfowl modeling attempts to use this method, especially for resolving gaps in the WBPHS coverage. As multiple data sets can be added to the original framework, integration efforts must not be restricted to the additional contribution of eBird data alone and could consider, for example, provincial atlases and regional helicopter surveys. [ABSTRACT FROM AUTHOR]

Hydro-Que´bec wants to divert the Kipawa River in northwest Que´bec from its natural streambed. While the first time visitor is likely to emphatically proclaim the Kipawa River as the most beautiful, most serene place they have ever encountered, hydro consultants and engineers, disconnected from the attractiveness of that place, are making cost/benefit recommendations that marginalize the inherent value of a free-flowing Kipawa. This paper will discuss the following points: (1) The Kipawa River has its own inherent value, which is related to the cost of simulating threatened white-water habitats in general. (2) The costs of recreating white-water habitats are more understandable through the study of man-made white-water venues. (3) The cost to recreate or simulate a threatened white-water habitat should be factored into the cost of the hydro-project feasibility. The Kipawa River's own inherent value should be factored into the cost of the Tabaret Diversion Project. (4) Methods of gaining community acceptance should be public and open: independent third-party arbitartion is recommended. Use of monetary incentives to encourage public acceptance is unethical, immoral and unjustly biased against the survival of white-water habitats. (5) Recreational use of white-water habitats, like the Kipawa River are increasingly important engines of economic growth in Canada and around the world. [Copyright &y& Elsevier]

Most habitat maps are presented as if they were a certain fact, with no indication of uncertainties. In many cases, researchers faced with the task of constructing such maps are aware of problems with the modelling data and of decisions that they make within the modelling process that are likely to affect the output, but they find it difficult to quantify this information. In some cases they attempt to evaluate the modelled predictions against independent data, but the summary statistics have no spatial component and do not address errors in the predictions. It is proposed that maps of uncertainty would help in the interpretation of these summaries, and to emphasize patterns in uncertainty such as spatial clustering or links with particular covariates. This paper reviews the aspects of uncertainty that are relevant to habitat maps developed with logistic regression, and suggests methods for investigating and communicating these uncertainties. It addresses the problems of subjective judgement, model uncertainty and vague concepts along with the more commonly considered uncertainties of random and systematic error. Methods for developing realistic confidence intervals are presented along with suggestions on how to visualize the information for use by decision-makers. [Copyright &y& Elsevier]

(1) This study tested the hypothesis that mechanical alteration of habitat, near Prince George, British Columbia, Canada, would reduce peak populations of snowshoe hares and their feeding, damage to coniferous seedlings. (2) In the altered habitat, population density and residency of hares were dramatically reduced, juvenile and subadult hares dominated the age class structure, and male hares were in consistently poor physical condition compared with those in the control habitat. (3) Despite favourable demographic responses, seedling mortality from hare browsing reached 80% in the altered habitat. (4) Complete scarification and/or application of herbicide would further reduce or eliminate vegetative food and cover and perhaps depress and maintain hare densities at levels below which damage. (<5%) to seedlings could be tolerated. [ABSTRACT FROM AUTHOR]

Non-indigenous species are often identified as threats to native species and communities. Yet, the mechanisms that enable many of these invaders to thrive and alter their newly invaded habitats are still not fully understood. This applies to habitats such as widespread sedimentary shorelines characterized by the presence of scattered biogenic clumps of blue mussels (Mytilus edulis) structurally more complex than bare sediments. In Atlantic Canada, some of these shorelines are numerically dominated by native mud crabs (Dyspanopeus sayi) but have been gradually invaded by the European green crab (Carcinus maenas). This study describes between-habitat (mussel clump vs. bare sediment) differences in density and diversity of invertebrates. It also tests the impact of juvenile green crabs in comparison to native mud crabs using two approaches: First, measuring habitat-related differences in these crabs' feeding rates on a common prey (soft-shell clams, Mya arenaria). Second, measuring their influence on invertebrate communities associated with mussel clumps. The results show that mussel clumps hold higher invertebrate density and diversity than surrounding sedimentary bottoms. In the laboratory, the feeding rates of native mud crabs were dependent on the type of habitat (sand flat > mussel clump), whereas those of green crabs were significantly higher and unrelated to the habitat in which predation occurred. In field experiments, juvenile green crabs were also the only predators that changed community structure in the mussel clump habitat. These results indicate that green crabs can cause a significant impact on native species and communities. Moreover, they suggest that the ability of this species to overcome the refuge provided by complex biogenic habitats for prey may represent an unexplored mechanism to explain this invader's expansion here and elsewhere. [ABSTRACT FROM AUTHOR]

Aim: To evaluate current and future dynamics of 25 tree species spanning United States and Canada. Location: United States and Canada. Methods: We combine, for the first time, the species compositions from relative importance derived from the USA's Forest Inventory Analysis (FIA) with gridded estimates based on Canada's National Forest Inventory (NFI‐kNN))‐based photo plot data to evaluate future habitats and colonization potentials for 25 tree species. Using 21 climatic variables under RCP 4.5 and RCP 8.5, we model climatic habitat suitability (HQ) within a consensus‐based multimodel ensemble regression approach. A migration model is used to assess colonization likelihoods (CL) for ~100 years and combined with HQ to evaluate the various combinations of HQ + CL outcomes for the 25 species. Results: At a continental scale, many species in the conterminous United States lose suitable climatic habitat (especially under RCP 8.5) while Canada and USA's Alaska gain climate habitat. For most species, even under optimistic migration rates, only a small portion of overall future suitable habitat is projected to be naturally colonized in ~100 years, although considerable variation exists among species. Main conclusions: For the species examined here, habitat losses were primarily experienced along southern range limits, while habitat gains were associated with northern range limits (especially under RCP 8.5). However, for many species, southern range limits are projected to remain relatively intact, albeit with reduced habitat quality. Our models predict that only a small portion of the climatic habitat generated by climate change will be colonized naturally by the end of the current century—even with optimistic tree migration rates. However, considerable variation among species points to the need for significant management efforts, including assisted migration, for economic or ecological reasons. Our work highlights the need to employ range‐wide data, evaluate colonization potentials and enhance cross‐border collaborations. [ABSTRACT FROM AUTHOR]

While there is no denying that oil sands development in the Athabasca Oil Sands Region (AOSR) has large impacts upon the habitat it disturbs, developers are legally required to return this land to “an equivalent land capability.” While still early in the process of reclamation, land undergoing reclamation offers an opportunity to study factors influencing reclamation success, as well as how reclaimed ecosystems function. As such, an Early Successional Wildlife Dynamics (ESWD) program was created to study how wildlife return to and use reclaimed upland boreal habitat in the AOSR. Wildlife data comprising 182 taxa of mammals, birds, and amphibians, collected between 2011 and 2017 and from five oil sands leases, were compared from multiple habitat types (burned [BRN], cleared [CLR], compensation lakes [COMP], logged [LOG], mature forest [MF], and reclaimed sites [REC]). Overall, similarity of wildlife communities in REC and MF plots varied greatly, even at 33 years since reclamation (31–62% with an average of 52%). However, an average community similarity of 52% so early in the successional process suggests that current reclamation efforts are progressing towards increased similarity compared to mature forest plots. Conversely, our data suggest that REC plots are recovering differently than plots impacted by natural (BRN) or other anthropogenic disturbances (LOG), which is likely due to differences associated with soil reconstruction and development on reclaimed plots. Regardless of the developmental trajectory of reclaimed habitats, progression towards increased wildlife community similarity at REC and MF plots is apparent in our data. While there is no expectation that reclaimed upland habitats will resemble or function identically to naturally occurring boreal forest, the degree of similarity observed in our study suggests that comparable ecological functionality is possible, increasing the probability that oil sands operators will be able to fulfill their regulatory requirements and duty to reclaim regarding wildlife and wildlife habitat. [ABSTRACT FROM AUTHOR]

Tree cavities provide a critical resource for cavity-nesting animals, and high quality cavities can be difficult for animals to acquire in habitats where competition is high. We investigated the breeding performance of Lewis's Woodpeckers in three habitat types in British Columbia, Canada in 2013 and 2014. We also assessed whether the number of nest competitors and cavity availability influenced the habitat specific breeding performance of this threatened cavity nesting species. We found that daily nest survival rate was lower in burned habitat (0.15 ± 0.08 (0.05–0.37)) than in live pine (0.72 ± 0.10 (0.51–0.87)) or cottonwood (0.69 ± 0.09 (0.51–0.83)) habitats. However, hatching success (the proportion of eggs that hatch) was lower in live pine habitat (0.59 ± 0.09 95% CI) than burned (0.77 ± 0.19 95% CI) or cottonwood (0.80 ± 0.07 95% CI) habitat, and the fledging success of successful nests in live pine and burned habitat (1.86 ± 0.31 and 1.88 ± 0.59 95% CI, respectively) was slightly lower than in cottonwood habitat (2.61 ± 0.45 95% CI). Consequently, Lewis's Woodpeckers in cottonwood habitat produced more fledglings per nesting attempt (2.05 ± 0.49 95% CI) than in live pine (1.53 ± 0.35 95% CI) or burned (0.79 ± 0.49 95% CI) habitat. Habitats differed in the number of nesting competitors and the number of suitable cavities surrounding active Lewis's Woodpecker nests. Our results showed that cavity density best explained breeding performance differences although the mechanisms remain unclear. There was no evidence that the number of heterospecific nest competitors, including the invasive European Starling (Sturnus vulgaris), explained or influenced Lewis's Woodpecker breeding performance. Cavity density influenced the productivity of successful nests but did not explain habitat differences in hatching success or daily nest survival. Further work is required to understand the mechanistic basis for the habitat specific breeding performance of Lewis's Woodpeckers. Habitat differences in breeding performance in British Columbia are not consistent with those in other regions, highlighting the importance of regionally-specific demographic data for managing species at risk. [ABSTRACT FROM AUTHOR]

Genetic diversity at immune genes and levels of parasitism are known to affect patterns of (dis)assortative mating in several species. Heterozygote advantage and/or good genes should shape mate choice originating from pathogen/parasite-driven selection at immune genes. However, the stability of these associations, and whether they vary with environmental conditions, are still rarely documented. In this study, we describe mating patterns in a wild population of tree swallows (Tachycineta bicolor) over 4 years and assess the effects of haemosporidian parasite infection and immune genetic diversity at β-defensin genes on those patterns within two habitats of contrasting environmental quality, in southern Québec, Canada. We first show that mating patterns were only very weakly related to individual status of infection by haemosporidian parasites. However, we found a difference between habitats in mating patterns related to infection status, which was likely due to a non-random distribution of individuals, as noninfected mating pairs were more frequent in lower quality habitats. Mating patterns also differed depending on β-defensin heterozygosity at AvBD2, but only for genetic partners outside of the social couple, with heterozygous individuals pairing together. Our study underlines the importance of considering habitat heterogeneity in studies of sexual selection. [ABSTRACT FROM AUTHOR]

A survey of the United States and Canadian governmental agencies investigated the environmental impact and relative invasiveness of free-roaming domestic non-native carnivores--dogs, cats, and ferrets. Agencies represented wildlife, fish, game, natural or environmental resources, parks and recreation, veterinary and human health, animal control, and agriculture. Respondents were asked to document the number and frequency of sightings of unconfined animals, evidence for environmental harm, and the resulting "degree of concern" in their respective jurisdictions. Results confirmed the existence of feral (breeding) cats and dogs, documenting high levels of concern regarding the impact of these animals on both continental and surrounding insular habitats. Except for occasional strays, no free-roaming or feral ferrets were reported; nor were there reports of ferrets impacting native wildlife, including ground-nesting birds, or sensitive species. This is the first study to report the relative impact of free-roaming domestic carnivores. Dogs and cats meet the current definition of "invasive" species, whereas ferrets do not. Differences in how each species impacts the North American environment highlights the complex interaction between non-native species and their environment. Public attitudes and perceptions regarding these species may be a factor in their control and agency management priorities. [ABSTRACT FROM AUTHOR]

Copyright of Environmental Reviews is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Phenacomys ungava Merriam, 1889, is an arvicoline rodent commonly known as the eastern heather vole. A small vole with a short tail and reddish to yellowish nose and eye rings, it is 1 of 2 currently recognized species in the genus Phenacomys. The species occurs in diverse habitats of the boreal forest ecosystem of Canada from Labrador to southern Yukon and from southern Quebec to southern Alberta, with isolated records from northeasternMinnesota. P. ungava is listed as ''Least Concern'' by the International Union for Conservation of Nature and Natural Resources. [ABSTRACT FROM AUTHOR]

Until recently, the sea ice habitat of polar bears was understood to be variable, but environmental variability was considered to be cyclic or random, rather than progressive. Harvested populations were believed to be at levels where density effects were considered not significant. However, because we now understand that polar bear demography can also be influenced by progressive change in the environment, and some populations have increased to greater densities than historically lower numbers, a broader suite of factors should be considered in demographic studies and management. We analyzed 35 years of capture and harvest data from the polar bear ( Ursus maritimus) subpopulation in Davis Strait, including data from a new study (2005-2007), to quantify its current demography. We estimated the population size in 2007 to be 2,158 ± 180 (SE), a likely increase from the 1970s. We detected variation in survival, reproductive rates, and age-structure of polar bears from geographic sub-regions. Survival and reproduction of bears in southern Davis Strait was greater than in the north and tied to a concurrent dramatic increase in breeding harp seals ( Pagophilus groenlandicus) in Labrador. The most supported survival models contained geographic and temporal variables. Harp seal abundance was significantly related to polar bear survival. Our estimates of declining harvest recovery rate, and increasing total survival, suggest that the rate of harvest declined over time. Low recruitment rates, average adult survival rates, and high population density, in an environment of high prey density, but deteriorating and variable ice conditions, currently characterize the Davis Strait polar bears. Low reproductive rates may reflect negative effects of greater densities or worsening ice conditions. © 2013 The Wildlife Society. [ABSTRACT FROM AUTHOR]

The population of loggerhead shrike (Lanius ludovicianus excubutirudes) in Grassland National Park of Canada (GNPC) has undergone a severe decline due to habitat loss and limitation. Shrike habitat availability is highly impacted by the biophysical characteristics of grassland landscapes. This study was conducted in the west block of GNPC. The overall purpose was to extract important biophysical and topographical variables from both SPOT satellite imagery and in situ measurements. Statistical analysis including Analysis of Variance (ANOVA), measuring Coefficient Variation (CV), and regression analysis were applied to these variables obtained from both imagery and in situ measurement. Vegetation spatial variation and heterogeneity among active, inactive and control nesting sites at 20 m × 20 m, 60 m × 60 m and 100 m × 100 m scales were investigated. Results indicated that shrikes prefer to nest in open areas with scattered shrubs, particularly thick or thorny species of smaller size, to discourage mammalian predators. The most important topographical characteristic is that active sites are located far away from roads at higher elevation. Vegetation index was identified as a good indicator of vegetation characteristics for shrike habitats due to its significant relation to most relevant biophysical factors. Spatial variation analysis showed that at all spatial scales, active sites have the lowest vegetation abundance and the highest heterogeneity among the three types of nesting sites. For all shrike habitat types, vegetation abundance decreases with increasing spatial scales while habitat heterogeneity increases with increasing spatial scales. This research also indicated that suitable shrike habitat for GNPC can be mapped using a logistical model with ATSAVI and dead material in shrub canopy as the independent variables. [ABSTRACT FROM AUTHOR]

Lewis's Woodpecker (Melanerpes lewis) has experienced population declines in both Canada and the United States and in 2010 was assigned a national listing of threatened in Canada. We conducted a two-year study (2004-2005) of this species at its northern range limit, the South Okanagan Valley in British Columbia, Canada. Our main objective was to determine whether the habitat features that influenced nest-site selection also predicted nest success, or whether other factors (e.g. cavity dimensions, clutch initiation date or time of season) were more important. Nest tree decay class, density of suitable cavities and total basal area of large trees were the best predictors of nest-site selection, but these factors were unrelated to nesting success. Estimates of demographic parameters (mean ± SE) included daily nest survival rate (0.988±0.003, years combined), nest success (0.52±0.08), clutch size (5.00±0.14 eggs), female fledglings per successful nest (1.31±0.11), and annual productivity (0.68±0.12 female fledglings per nest per year). Although higher nest survival was associated with both early and late initiated clutches, early-initiated clutches allowed birds to gain the highest annual productivity as early clutches were larger. Nests in deep cavities with small entrances experienced lower predation risk especially during the peak period of nest predation. We concluded that nest-site selection can be predicted by a number of easily measured habitat variables, whereas nest success depended on complicated ecological interactions among nest predators, breeding behaviors, and cavity features. Thus, habitat-based conservation strategies should also consider ecological factors that may not be well predicted by habitat. [ABSTRACT FROM AUTHOR]

Copyright of Conservation Biology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Malyshev, A., and Quijón, P. A. 2011. Disruption of essential habitat by a coastal invader: new evidence of the effects of green crabs on eelgrass beds. – ICES Journal of Marine Science, 68: 1852–1856.Eelgrass (Zostera marina) beds have been declining in Atlantic Canada and elsewhere, partly as a result of sediment disruption and direct feeding/cutting of basal meristems by the green crab (Carcinus maenas). Green crabs are detrimental to eelgrass beds, and field and laboratory experiments have confirmed that the deleterious role of this invasive species is mediated by at least two mechanisms, depending on the size/age of the crabs: uprooting by adults and grazing by juveniles. Eelgrass uprooting and grazing by green crabs are likely to contribute to further declines or a lack of recovery of eelgrass beds. [ABSTRACT FROM PUBLISHER]

Determining how biological traits are related to the ability of groups of organisms to become economically damaging when established outside of their native ranges is a major goal of population biology, and important in the management of invasive species. Little is known about why some taxonomic groups are more likely to become pests than others among plants. We investigated traits that discriminate vascular plant genera, a level of taxonomic generality at which risk assessment and screening could be more effectively performed, according to the proportion of naturalized species which are pests. We focused on the United States and Canada, and, because our purpose is ultimately regulatory, considered species classified as weeds or noxious. Using contingency tables, we identified 11 genera of vascular plants that are disproportionately represented by invasive species. Results from boosted regression tree analyses show that these categories reflect biological differences. In summary, approximately 25% of variation in genus proportions of weeds or noxious species was explained by biological covariates. Key explanatory traits included genus means for wetland habitat affinity, chromosome number, and seed mass. [ABSTRACT FROM AUTHOR]

The macfarlanei subspecies of the Western Screech-owl (Megascops kennicottii) resides in the dry southern interior of British Columbia and is federally endangered in Canada. We captured and radio-tagged 11 adult screech-owls (6M, 5F) between July 2005 and January 2008 to collect ecological information needed to direct effective conservation. We collected point radiolocations from tagged owls to estimate seasonal and year-round home ranges with the 95% isopleth of the utilization distribution calculated using fixed kernel methods. Screech-owl home ranges averaged 64.5 ha (s = 10.6, n = 5), with no substantial difference in size between males and females. Owls used considerably smaller areas during the breeding season (t = 20.4 ha, s = 15.3, n = 7) than the non-breeding season (x = 88.6 ha, s = 44.5, n = 6). During the breeding season, males and females of a single pair overlapped extensively, whereas outside the breeding season very little overlap occurred within pairs. We did not detect overlap between neighbouring pairs. Home ranges of Western Screech-owls were highly associated with riparian forests; most screech-owls had ⩾10 ha of riparian forested habitats within their home ranges. These results have implications for habitat conservation for this endangered species. [ABSTRACT FROM AUTHOR]

Microtus miurus Osgood, 1901, is a cricetid commonly called the singing vole. An average-sized, short-tailed vole, it is 1 of 62 species in the genus Microtus. It occurs in northwestern Canada and Alaska, where it inhabits well-drained tundra and extends into subalpine and alpine regions. It is unique among arvicolines in that it not only hoards underground but also constructs haypiles above ground. It is listed as a species of ''Least Concern'' by the International Union for Conservation of Nature and Natural Resources. [ABSTRACT FROM AUTHOR]

Estimating the range at which harbor porpoises can detect prey items and environmental objects is integral to understanding their biosonar. Understanding the ranges at which they can use echolocation to detect and avoid obstacles is particularly important for strategies to reduce bycatch. Transmission loss (TL) during acoustic propagation is an important determinant of those detection ranges, and it also influences animal detection functions used in passive acoustic monitoring. However, common assumptions regarding TL have rarely been tested. Here, TL of synthetic porpoise clicks was measured in porpoise habitats in Canada and Denmark, and field data were compared with spherical spreading law and ray-trace (Bellhop) model predictions. Both models matched mean observations quite well in most cases, indicating that a spherical spreading law can usually provide an accurate first-order estimate of TL for porpoise sounds in porpoise habitat. However, TL varied significantly (±10 dB) between sites and over time in response to variability in seafloor characteristics, sound-speed profiles, and other short-timescale environmental fluctuations. Such variability should be taken into account in estimates of the ranges at which porpoises can communicate acoustically, detect echolocation targets, and be detected via passive acoustic monitoring. [ABSTRACT FROM AUTHOR]

We conducted a mark–release–recapture survey of a peatland dragonfly ( Leucorrhinia hudsonica) in each of two years (2002; 2003) in a harvested forest landscape in western Newfoundland, Canada. The odds of an individual male moving between peatlands was influenced by both the distance between peatlands and the type of intervening habitat (the matrix). Specifically, at meso scales (>700 m) there was a positive effect of the amount of cut matrix between peatlands on the odds of moving, but at fine scales (<700 m) there was the opposite effect; proportionally fewer individuals moved between peatlands. The odds of moving out of a peatland decreased as the surface area of water in the peatland increased. Multi-state mark–recapture models showed that the daily probability of a male moving between any two peatlands was 1.9% in 2002 and 6.9% in 2003 (n=1527 and 1280 marked individuals). The results suggest that additional empirical studies that directly measure patterns of movement with respect to landscape structure at multiple spatial scales in other taxa and situations are needed in order to uncover other possible non-linear changes in behavior. [ABSTRACT FROM AUTHOR]

We investigated the relationships among landscape quality, gene flow, and population genetic structure of fishers ( Martes pennanti) in ON, Canada. We used graph theory as an analytical framework considering each landscape as a network node. The 34 nodes were connected by 93 edges. Network structure was characterized by a higher level of clustering than expected by chance, a short mean path length connecting all pairs of nodes, and a resiliency to the loss of highly connected nodes. This suggests that alleles can be efficiently spread through the system and that extirpations and conservative harvest are not likely to affect their spread. Two measures of node centrality were negatively related to both the proportion of immigrants in a node and node snow depth. This suggests that central nodes are producers of emigrants, contain high-quality habitat (i.e., deep snow can make locomotion energetically costly) and that fishers were migrating from high to low quality habitat. A method of community detection on networks delineated five genetic clusters of nodes suggesting cryptic population structure. Our analyses showed that network models can provide system-level insight into the process of gene flow with implications for understanding how landscape alterations might affect population fitness and evolutionary potential. [ABSTRACT FROM AUTHOR]

The fisher ( Martes pennanti) has recently recovered from historic extirpations across much of its geographic range. There are at least five explanations for the recovery of the fisher, including changes in the amount of habitat, the suitability of habitat, trapping pressure, societal attitudes toward predators, and climate. We evaluated a recovering fisher population in Ontario to test two conditions we viewed as necessary to support the hypothesis that fisher populations have increased due to an increase in the amount of forested land. First, we tested whether the amount of forested land has increased. Second, we tested whether contemporary fisher abundance (and therefore habitat quality) was related to the amount of forest. Topographic maps showed that the proportion of forested land in the study area had increased by 1.9% per decade since 1934 and 3.3% per decade since 1959, likely as a result of land conversion from agricultural uses. Overall the proportion of the study area that was forested increased from 29% to 40% during 1934 to 1995. Census data from the region indicated that there had been a decline in the amount of land area being farmed during the last 50 years. Recent livetrapping data showed that fisher abundance was positively related to the proportion of landscapes that were forested. Based on our results, we could not reject the hypothesis that an increase in the amount of forested land has contributed to the recovery of fisher populations. [ABSTRACT FROM AUTHOR]

On NW Atlantic rocky shores, the main basal organisms in intertidal communities are seaweeds ( Ascophyllum nodosum, Fucus spp. and Chondrus crispus) and filter feeders (barnacles, Semibalanus balanoides, and mussels, Mytilus spp.). Their ecology has been extensively studied in New England (United States), but knowledge gaps exist for northern shores, which are subjected to stronger environmental stress. Therefore, we studied the above organisms on Canadian shores. We quantified the summer abundance of these seaweeds and filter feeders across full vertical (intertidal elevation) and horizontal (wave exposure and winter ice scour) environmental gradients on the Gulf of St. Lawrence and open Atlantic coasts of Nova Scotia. At the regional scale along the open Atlantic coast, seaweeds showed similar abundances in Nova Scotia than values reported for New England. However, both filter feeders were considerably less abundant in Nova Scotia. At the local scale in Nova Scotia, intense winter ice scour (which only occurs on the Gulf of St. Lawrence coast) was associated with a very low abundance of all species except barnacles. Spatial trends in Nova Scotia were similar to patterns known for certain species elsewhere, such as A. nodosum being almost restricted to sheltered habitats, regardless of elevation, and C. crispus being almost restricted to low elevations, regardless of exposure. Other trends were, however, characteristic of Nova Scotia, such as C. crispus being frequent at low elevations in exposed habitats, unlike in New England, where mussels often predominate there because of competitive advantages. In Nova Scotia, mussels were always restricted to cracks and crevices, unlike in New England, where they form extensive intertidal beds on exposed shores. The direct effects of increased environmental stress and indirect effects through altered interspecific interactions might explain the regional differences in local species distribution, which will require experimental validation. [ABSTRACT FROM AUTHOR]

The mountain pine beetle (Dendroctonus ponderosae) outbreak in western Canada poses significant conservation concern; thus, insights into its effects on wildlife habitat are essential. We used generalized linear mixed models to examine the influence of quaking aspen (Populus tremuloides) and mountain pine beetle-infected lodgepole pine (Pinus contortus) on nest patch selection of red-breasted nuthatches (Sitta canadensis) in central British Columbia, Canada. Prior to the outbreak, nuthatches selected nest patches with 64% more suitable nest trees (standing dead aspen, ≥12.5 cm dbh) than available (103 trees/ha vs. 63 trees/ha, respectively), but in outbreak years nuthatches chose nest patches with 37% more beetle-infected pine trees than available (63 trees/ha vs. 46 trees/ha, respectively). Our results suggest that nuthatches select sites that maximize nesting and foraging opportunities and, during food pulses, may trade off higher densities of suitable nest trees for higher densities of foraging trees. [ABSTRACT FROM AUTHOR]

The combined effects of multiple ecological stressors determine the net impact of global change on environmentally sensitive alpine and polar environments. For example, climate warming and nitrogen deposition both increasingly affect ecosystems at high elevations. We hypothesized that the net impact of warming and nitrogen on alpine plankton differs between consumers and producers because of the greater environmental sensitivity of higher trophic levels. Also, we expected that habitat conditions would mediate the responses of plankton to these two stressors as sediments function as ecological buffers against environmental change. These hypotheses were tested in a growth chamber by applying temperature (8 vs. 15°C) and nitrogen (200 vs. 1000 μg N L-1) treatments to a planktonic alpine community in the presence and absence of sediments obtained from Pipit Lake, Banff National Park, Alberta. A significant nitrogen-temperature interaction affected phytoplankton abundance because the positive effect of fertilization depended on warming. Warming also amplified the effect of nitrogen on herbivores while suppressing the fecundity of omnivores. The presence of sediments suppressed the positive effect of warming on herbivores, but stimulated omnivores. The observed prevalence of non-additive effects highlights the strong potential for global change causing future ecological surprises in alpine environments. [ABSTRACT FROM AUTHOR]

Standardized survey methods are important for obtaining reliable information on wildlife populations. As a precursor to creating a regional bat-survey (Chiroptera) protocol, we distributed a questionnaire via e-mail to biologists responsible for conducting bat surveys in the United States and Canada. We received 415 responses from 45 states and 7 Canadian provinces or territories. Most of the responses were from western North America. Based on these responses, we characterized the biologists responsible for bat surveys, their objectives and methods, and the habitat types and spatial scales surveyed. Most respondents were government employees, had <5 years of experience working with bats, and had <20% of their professional responsibilities dedicated to bats. Surveys were most likely to occur in forests and at sites ≤ 1 km² in area. The 3 most important objectives identified by respondents for conducting bat surveys, in rank order, were to 1) create a list of species in an area, 2) monitor presence or abundance of a species at a structure, and 3) determine presence of a single species in an area. Experienced (> 10 yr) surveyors tended to employ a wider variety of methods than those with less experience. We discuss how the results of this questionnaire will be used to draft a regional bat-survey protocol to better address the needs of its target audience. Using the Internet to survey the target audience proved to be a very useful step in the development of a standard bat-survey protocol. We believe similar methods should be considered for other taxa as a precursor to creation of standard survey methods. [ABSTRACT FROM AUTHOR]