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To recover species at risk, it is necessary to identify habitat critical to their recovery. Challenges for species with large ranges (thousands of square kilometres) include delineating management unit boundaries within which habitat use differs from other units, along with assessing any differences among units in amounts of and threats to habitat over time. We developed a reproducible framework to support identification of critical habitat for wide-ranging species at risk. The framework (i) reviews species distribution and life history; (ii) delineates management units across the range; (iii) evaluates and compares current and (iv) potential future habitat and population size and (v) prioritizes areas within management units based on current and future conditions under various scenarios of climate change and land-use. We used Canada Warbler (Cardellina canadensis) and Wood Thrush (Hylocichla mustelina) in Canada as case studies. Using geographically weighted regression models and cluster analysis to measure spatial variation in model coefficients, we found geographic differences in habitat association only for Canada Warbler. Using other models to predict current habitat amount for each species in different management units, then future habitat amount under land use and climate change, we projected that: (1) Canada Warbler populations would decrease in Alberta but increase in Nova Scotia and (2) Wood Thrush populations would increase under most scenarios run in Quebec, New Brunswick and Nova Scotia, but not in Ontario. By comparing results from future scenarios and spatial prioritization exercises, our framework supports identification of critical habitat in ways that incorporate climate and land-use projections. [ABSTRACT FROM AUTHOR]

Seabird bycatch in commercial fisheries has been a growing conservation concern over the past 25 years. Large-scale fisheries employing gears known to incidentally catch seabirds operate off eastern Canada, however, regional bycatch information is limited., Using data collected from 1998-2011 by observers onboard Canadian domestic and foreign vessels, fishery sectors and target fisheries taking seabirds were identified, as were the seabirds most frequently taken. In addition, maps of seabird bycatch rates were used to identify localized areas where catch rates were high., Seabird bycatch was widespread. Despite generally low observer coverage, > 5000 bird deaths were recorded; most observed mortalities occurred in gillnet and longline sectors during summer and autumn. While the overall magnitude of seabird bycatch has likely decreased substantially since closure of the Atlantic cod Gadus morhua and Atlantic salmon Salmo salar gillnet fisheries in 1992, localized areas with high bycatch rates persist., For example, in Baffin Bay and Davis Strait, bycatch rates of northern fulmars Fulmarus glacialis were high in gillnet and longline fisheries targeting Greenland halibut Reinhardtius hippoglossoides near breeding colonies. In offshore areas of the Grand Bank, catch rates of migrant shearwaters ( Puffinus and Calonectris spp.) were high in deep-set gillnet fisheries for Greenland halibut and monkfish Lophius americanus during summer. In inshore regions of eastern Newfoundland, gillnets set for Atlantic cod near breeding colonies resulted in high bycatch rates of murres Uria spp. and shearwaters during summer. High bycatch rates were also observed in pelagic longline fisheries along the Scotian Shelf., While the observer data have highlighted several localized areas with high bycatch rates, information for inshore gillnet fisheries, which take seabirds but are poorly covered by the observer programme, and regional information on fishing effort must both be considered for comprehensive assessment of seabird risk areas and consequent management needs in eastern Canada., Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Bogs, or ombrotrophic peatlands, are well represented in parts of southeastern Canada but are subjected to increasing pressure from the peat industry. We assessed the impact of peat mining on small mammals inhabiting unexploited bog fragments on the periphery of mined bogs. We conducted two separate studies in bogs mined to different levels (0-83%) in southeastern Québec and New Brunswick. The first study used a low sampling effort over 1 month in 26 bogs, while the second used a high sampling effort of 6 months spread across 2 years in 12 bogs. Of the 15 small-mammal species encountered, only 2 were bog specialists. Abundance and species richness of small mammals in bog fragments increased significantly with percentage of area mined and, in some cases, increased with bog area. Both studies suggest that disturbances resulting from peat mining facilitate the invasion of more generalized small-mammal species. Furthermore, small mammals were more abundant near forest or mined edges than at bog centers, and some species responded strongly to vegetation cover. The response of small mammals to peat mining contrasts with the one documented for birds, amphibians, and plants.Les bogs, ou tourbières ombrotrophes, recouvrent une partie importante du sud-est canadien. Ils subissent toutefois des pressions croissantes de l'industrie de la tourbe. Nous avons évalué l'impact de l'exploitation de bogs sur les petits mammifères occupant des fragments naturels situés en périphérie de bogs exploités. Nous avons effectué deux études distinctes dans des bogs soumis à différents degrés d'exploitation (0-83 %) au Québec et au Nouveau-Brunswick. La première comportait un effort d'échantillonnage restreint à 1 mois dans 26 bogs, et la deuxième, plus intensive, portait sur 6 mois d'échantillonnage répartis sur 2 ans dans 12 bogs. Quinze espèces de petits mammifères ont été capturées, dont 2 spécialistes des tourbières. Dans les fragments naturels en périphérie de bogs exploités, la richesse en espèces et l'abondance de petits mammifères augmentaient en fonction de l'importance de la surface exploitée du bog, et dans certains cas, avec la superficie du bog. Les deux études indiquent que l'exploitation des bogs favorise l'invasion de petits mammifères d'espèces généralistes. De plus, les petits mammifères étaient plus abondants près des bordures exploitées et forestières. Certaines espèces étaient également influencées par la structure de la végétation. La réaction des petits mammifères à l'exploitation des bogs diffère de celle rapportée pour les oiseaux, les amphibiens et les plantes. [ABSTRACT FROM AUTHOR]

Lake Ontario and St. Lawrence River (LOSL) wetland bird abundance and diversity are greatly influenced by lake and river hydrology. Our study used an interdisciplinary ecosystem approach, blending avian and plant ecology, ecohydraulic, statistical ecology and modelling to evaluate potential impacts of water level fluctuations on indicator species representative of the wetland breeding bird assemblages in the entire LOSL freshwater system. Multi-year (2000-2003) bird surveys captured bird distribution and density in wetland habitats under varying degrees of water inandation, depth and fluctuation. Analyses revealed strong associations between estimated breeding pair densities and plant communities, water depth, and degree of water level fluctuation during the breeding season for a suite of wetland bird species using marsh, wet meadow, shrub swamp and treed swamp habitats. These quantitative associations were used to develop wetland bird performance indicators for use in a LOSL water regulation review study. Several bird species also nest at or near the water surface and are thus vulnerable to nest flooding or stranding. Changes to the seasonal hydrology of Lake Ontario and St. Lawrence River that result in an increased frequency or magnitude of these nest failure events may have a significant impact on regional population sustainability. Long term nest record databases were analyzed to create nesting flooding and stranding probability equations based on water level increases and decreases during the breeding season. These species-specific nesting relationships were incorporated into a reproduction index. Many breeding bird species were strongly associated with specific wetland plant communities. Predicted habitat suitability, as measured by estimated breeding pair density, can also change significantly within a specific wetland plant community based solely on changes in water depth during the breeding season. Three indicator species, Black Tern, Least Bittern and Virginia Rail were selected as key environmental performance indicators for alternate regulation plan comparisons. Water regulation criteria should be such that the long term diversity and abundance of wetland plant communities and frequency of spring flooding in marsh habitats during breeding are not reduced. Magnitude and frequency of water level change during the nesting season (May-July) can also adversely impact reproductive success of many wetland bird species. As such, regulation criteria that increase the seasonal magnitude and frequency of water level change may be detrimental to the long term viability of certain regional breeding bird populations.