Barred Owl Conservation Management Plan 2016-2021 - Alberta Species at Risk Conservation Management Plan No. 14
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Barred Owl Conservation Management Plan 2016-2021 Alberta Species at Risk Conservation Management Plan No. 14
ISBN 978-1-4601-2656-1 (PDF) ISSN: 1922-9984 Cover photo: Gordon Court For copies of this report, visit the Species at Risk Program web site at: http://aep.alberta.ca/fish-wildlife/species-at-risk/default.aspx This publication may be cited as: Alberta Environment and Parks. 2016. Barred Owl Conservation Management Plan 2016-2021. Alberta Environment and Parks. Species at Risk Conservation Management Plan No. 14. Edmonton, AB. 10 pp. ii
PREFACE Albertans are fortunate to share their province with a diversity of wild species. A small number of these species are classified as Species of Special Concern because they have characteristics that make them particularly sensitive to human activities or natural events. Special conservation measures are necessary to ensure that these species do not become Endangered or Threatened. Conservation management plans are developed for Species of Special Concern to provide guidance for land and resource management decisions that affect the species and their habitat. These plans are intended to be a resource tool for provincial and regional fish and wildlife, land and resource management staff in Alberta Environment and Parks and other government departments. Conservation management plans provide background information including species biology, threats to species and habitat, and inventory/monitoring history. Plans also provide a goal, objectives, and actions (management recommendations). Management recommendations are typically categorised into inventory and monitoring needs; habitat management and conservation; education and communication; and additional management considerations as required. Conservation management plans are generally prepared by an Alberta Environment and Parks fish and wildlife biologist who has been designated as the provincial species lead. Writers from outside the department are occasionally sought to prepare plans for species for which there is little in-house expertise. In order to ensure accuracy and utility, each plan is reviewed by a species expert and a designated provincial representative from forestry or land management programs. In some cases there may be additional reviewers from staff, industry, and other agencies. Conservation management plans are internal guidance documents. They are implemented under the guidance of the species lead and are “living” documents that can be revised at any time as required. Conservation management plans are more succinct than the recovery plans that are prepared for Endangered and Threatened species and do not involve participation of a multi- stakeholder team. Conservation management plans are approved by the Director of Species at Risk, Non-Game and Wildlife Disease Policy. Plans will be reviewed annually by the species lead and updated if necessary, and a more in-depth review will occur five years after a plan’s approval. iii
TABLE OF CONTENTS PREFACE ...................................................................................................................................... iii ACKNOWLEDGEMENTS ............................................................................................................ v EXECUTIVE SUMMARY ...........................................................Error! Bookmark not defined. 1.0 INTRODUCTION ................................................................................................................. 1 1.1 Breeding Biology and Habitat Requirements ....................................................................... 1 1.2 Threats to the Population ...................................................................................................... 4 1.3 Inventory and Monitoring History ........................................................................................ 4 2.0 GOALS AND OBJECTIVES ................................................................................................ 5 2.1 Goals ..................................................................................................................................... 5 2.2 Objectives ............................................................................................................................. 5 3.0 MANAGEMENT PLAN ....................................................................................................... 6 3.1 Monitoring and Assessment .................................................................................................. 6 3.2 Research and Management ................................................................................................... 6 3.3 Habitat Management ............................................................................................................. 6 3.4 Industrial Recommendations ................................................................................................ 7 3.5 Education and Communication ............................................................................................. 8 3.6 Regulation and Policy ........................................................................................................... 8 4.0 SUMMARY ........................................................................................................................... 9 5.0 LITERATURE CITED ........................................................................................................ 10 TABLE OF FIGURES Figure 1. Records from targeted barred owl survey stations .......................................................... 2 Figure 2. Current estimate of barred owl distribution within Alberta ............................................ 3 iv
EXECUTIVE SUMMARY The barred owl (Strix varia) is a Species of Special Concern in Alberta because it requires large tracts of old mixedwood forests and is subject to increased predation risk as these forests become more fragmented in Alberta. The increasing demand for forest resources and the expanding industrial footprint in the province threatens the persistence of habitat for the barred owl. Some populations of barred owls are expected to decline as old mixedwood forest declines and becomes more fragmented. The barred owl occupies a wide extent of ecological regions in Alberta where the forests are old and there is a mix of large deciduous trees and snags and old conifer forest. Barred owls nest in the cavities of large balsam poplar (Populus balsamifera) and trembling aspen (Populus tremuloides) formed by the decay and damage caused by natural processes. There are a number of species that also rely on intact old mixedwood forest whose status is listed as Sensitive or Species of Special Concern. Barred owls have much larger territories than many of these species and therefore are considered suitable as an indicator, focal species or perhaps even an umbrella species for a wider assemblage of species that rely on old mixedwood forests. Further evaluation of this consideration that barred owls are a useful and suitable indicator of the larger assemblage of species that rely on old mixedwood forest is recommended. This plan recommends managing for barred owl habitat at multiple scales by tracking habitat using existing barred owl models at landscape scales while also addressing objectives for habitat management at the operational, or stand-level scale. There are several habitat models that can be used to project changes across scenarios of industrial development and resource utilization habitat at the scale of the landscape. Examples of habitat management at operational scales include: implementing a habitat avoidance approach to site selection for industrial development, the retention of old forest patches, snags and structure within stands, and avoiding disturbance during the nesting period. ACKNOWLEDGEMENTS Several people provided input and/or reviewed comments throughout the various stages of plan development, including: Dave Stepnisky, Lisa Wilkinson, Michelle Bacon, Jessica Lockhart, and Sandi Robertson (Alberta Environment and Parks). v
1.0 INTRODUCTION The barred owl (Strix varia) is identified as a Species of Special Concern in Alberta. Barred owl populations, estimated to be less than 2000 breeding individuals (Alberta Sustainable Resource Development 2010), occur in mixedwood boreal, foothills and aspen parkland forests throughout the province. Often used as an indicator of old mixedwood forest in Canada, loss and degradation of mature forest habitat presents the highest concern for barred owl populations in Alberta. 1.1 Breeding Biology and Habitat Requirements Barred owls are widely distributed in old mixedwood forest throughout North America. In Alberta, barred owls inhabit mature forests in the mixedwood boreal, Rocky Mountain foothills and aspen parkland ecoregions (Figure 1). Barred owls are highly territorial, typically monogamous, and pairs maintain their territory in successive years. The average home range size of barred owls in Alberta is typically 300ha in forested regions (Olsen 1999, Russell unpublished data). The nesting period starts in early spring and lasts until late May. Eggs are laid in late March or early April, and a brood of 1-5 young hatches approximately 30 days later. Owlets are mostly flightless for 12 weeks but leave the nest after only 4-5 weeks. During this pre-flight period, owlets reduce their risk of predation by climbing leaning trees and perching high above the ground, often in cover. Consequently, maintaining structural diversity in stands, such as partially fallen trees and snags, will allow young owls to climb to safe perches. In addition, sites with more diversity in composition and vertical structure make it more difficult for potential predators to see the vulnerable young owls. Young owls are capable of sustained flight at 12 weeks at which time they become more self-sufficient. Young disperse at approximately 4-5 months of age (Mazur and James 2000, Alberta Sustainable Resource Development 2005). Due to their nesting and foraging strategies, barred owls require specific habitat features. Barred owls prefer unfragmented, mature and old growth mixedwood forest because of the greater availability of nesting cavities in old snags and the high availability and variety of prey (Mazur and James 2000, Priestley 2004, Alberta Sustainable Resource Development 2005). Tall trees or snags with large diameters, such as balsam poplar (Populus baslsamifera) and aspen (P. termuloides), are typically used as nest sites (Olsen et al. 2006). Barred owls nest in natural cavities that are formed from disease or broken branches, or in the tops or hollow “chimneys” of broken snags. The succession process that establishes these natural nest cavities takes over a century after a forest is disturbed and the appropriate nest structures (e.g. snags) have a finite lifetime as they degrade or fall down. Hence, effective management of barred owl nesting habitat should focus on retaining mature forest with many large diameter trees to better ensure that appropriate nesting cavities are available through time. Barred owls are an indicator or umbrella species for old growth boreal forests because they are non-migratory, have large home ranges, and require old forest within their territories for nesting (Olsen et al. 2006, Russell 2008). Protecting blocks of undisturbed forest with mature upland mixedwood overstory, large diameter snags, and more complex understory will benefit barred owl habitat as well as the potential to protect a wide assemblage of other species including Bay-
breasted warbler (Dendroica castanea), Canada warbler (Wilsonia canadensis), Black-throated green warbler (Setophaga virens), American marten (Martes americana), Myotis bats (Myotis sp.) and other old mixedwood dependent species. Figure 1. Records from targeted barred owl survey stations where barred owls were detected or not detected and all FWMIS locations of barred owls (presence only) from the Fish and Wildlife Management Information System maintained by Alberta Environment and Parks. The Natural Regions and Subregions are provided in the background to demonstrate the basis of range delineation. 2
Figure 2. Current estimate of barred owl distribution within Alberta. 3
1.2 Threats to the Population 1.2.1 Loss of Old Growth Forest Habitat Loss and fragmentation of old growth forest resulting from anthropogenic disturbances such as forestry and industrial development are the greatest threats to barred owls in Alberta. Forestry operations and fire impact forest age structure and composition, while energy and road development reduce forest amount, often permanently, and fragment otherwise contiguous tracts of habitat. Barred owls nest in cavities in old deciduous trees, typically over 100 years old, which have a large diameter (minimum dbh of 36 cm). In addition, they require old forest for roosting and foraging during both the breeding and non-breeding periods. Present forest management practices in Alberta aim to harvest deciduous trees at an average of 60 years of age and coniferous trees at an average of 80 years of age. Current forestry practices that target older forest stands for preferential harvest result in the loss of large diameter snags (Priestly 2004, Olsen et al. 2006, Fish and Wildlife Division 2008). While large tree retention, or buffers around existing nest sites may mitigate for short-term impacts to breeding owls, solely protecting nest sites in single, large diameter trees will not provide adequate management for barred owl habitat. Barred owls hold large territories and require contiguous tracts of mature forest throughout their home ranges. Management should therefore occur at both the local and landscape scale in order to ensure long-term habitat supply for the entire life cycle (not just nest features) for this owl species. 1.2.2 Increased Predation Risk Barred owls may become more susceptible to increased competition and depredation by other raptors in highly disturbed habitat. The fragmented landscape and increased edge habitat that result from dispersed clearcuts and energy developments provides greater opportunities for larger predators such as great horned owls (Bubo virginianus) to establish territories. Their presence negatively impacts barred owl populations due to increased predation risk and competition for food resources (Fish and Wildlife Division 2008, Olsen 1999, Russell 2008). 1.3 Inventory and Monitoring History The abundance, distribution and habitat requirements of barred owl in Alberta have been well documented. Barred owl occurrence and distribution in Alberta between 1912 and 1999 was compiled with records from published literature, museum collections, banding records and personal communications. Two hundred and ninety-seven occurrence reports were included in the 87-year summary although only 46 nests were located (Priestly 2004). Six intensive studies have been conducted on the barred owl in Alberta (Takats 1998; Olsen 1999; Grossman 2003; Piorecky 2003; Russell 2008; Alberta Sustainable Resource Development- Grande Prairie 2009- 2011, unpublished). Takats examined distribution and abundance of barred owls in the Foothills Model Forest (1998). The impacts of harvest regimes in north-central Alberta were studied by Olsen (1999). Barred owl presence and abundance at the landscape scale was analyzed relative to biophysical characteristics of the forest in east-central Alberta (Grossman 2003) and the Foothills Natural Region (Piorecky 2003). Habitat selection across numerous spatial scales in a forest patch within an agricultural landscape was modeled by Russell (2008). Barred owl presence and 4
abundance was surveyed within the northern boreal by the Joint Oil Sands Monitoring Program (2013) and existing habitat models were evaluated for this region (AEMERA 2015). In recent years, efforts to collect long-term trend data on the population status of barred owl in Alberta have been coordinated by provincial monitoring initiatives such as the Alberta Nocturnal Owl Survey and Alberta Biodiversity Monitoring Institute. The Alberta Nocturnal Owl Survey is a provincial survey largely conducted by volunteer citizen scientists to conduct auditory nocturnal owl surveys with the goal of collecting long term trend information on owls. The Alberta Nocturnal Owl Survey began as a full program in 2002 and continues to this day (Beaverhill Bird Observatory 2013). The Alberta Biodiversity Monitoring Institute (ABMI) has anecdotally recorded barred owls as part of their songbird bird monitoring initiatives, and have expanded their program to include owl monitoring. The historical surveys conducted by ABMI tend to be poor at detecting nocturnal owl species, as such, the ABMI staff and advisors are in the process of creating nocturnal monitoring protocols that will improve data collection for long term monitoring of species such as the barred owl (E. Bayne pers. comm.). The current population estimate of barred owls in Alberta is unknown, although some estimates have been extrapolated from the available information. The report listing barred owl as a Species of Special Concern states “the species is considered to be relatively rare and likely exceeds 1000 individuals” (Fish and Wildlife Division 2008), while the Wild Species General Status Listing of 2010 suggests less than 2000 breeding individuals in Alberta (Alberta Sustainable Resource Development 2010). 2.0 GOALS AND OBJECTIVES The following goals and objectives are based on current knowledge of barred owls. 2.1 Goals Maintain current barred owl population and distribution, and improve habitat availability to ensure species survival. 2.2 Objectives • Review and evaluate the available Resource Selection Function (RSF) and Habitat Suitability Index (HSI) models (Olsen 1999, Russell 2008, Fisher et al. 2009, Piorecky 2003), for various regions of Alberta. The resulting model(s) should be validated using local data when available and implemented in landscape plans (including but not limited to Forest Management Plans and Landuse Framework Plans) • Inform the public and industry about the importance of preserving barred owl habitat (e.g. old snags, mixedwood), and create educational material to aid in identifying barred owl nests. • Implement land use guidelines to reduce disturbance within barred owl habitat and especially during the nesting period. • Continue to encourage research aimed at understanding landscape requirements of barred owls relative to demographic performance and long-term persistence. 5
3.0 MANAGEMENT PLAN 3.1 Monitoring and Assessment Barred owls respond reliably to the broadcasts of conspecific vocalizations (Takats 1998, Olsen 1999, Grossman 2003, Piorecky 2003, Russell 2008), and as such call playback surveys can be used to effectively monitor trends in this species. In order to track trends in barred owl populations in the long-term, sampling of areas across the province should be conducted using recognized call playback survey methodology. Future efforts should focus on: • Ensuring surveys aimed at detecting barred owls are incorporated in provincial monitoring initiatives (i.e. Alberta Biodiversity Monitoring Program). • Ensuring that standard methodologies are adopted and agreed upon for any research program and/or long-term monitoring program being initiated in Alberta. 3.2 Research and Management Areas in the northeastern and northwestern parts of Alberta where there is a high industrial footprint are lacking data about occupancy and population trends of barred owls. Efforts to increase survey effort in the north have been initiated (Joint Oil Sands Monitoring Program, Alberta Environmental Monitoring, Evaluation and Reporting Agency, and the University of Alberta) and will continue to provide information on the distribution and relative density of barred owls in the boreal mixedwood and highland ecological subregions. Habitat models for barred owls in the Calling Lake (Olsen 1999), Athabasca (Russell 2008), Eastern Slopes (Piorecky 2003), and Lower Athabasca (Fisher et al. 2009) regions of Alberta have been developed. Efforts to test and validate these models across a large portion of barred owl range in Alberta are ongoing. The validation of existing barred owl habitat models has shown that not all of the predicted potential territories are occupied and the demographic performance of these territories are not homogenous. In order to improve and refine existing models, it will be important to collect information on demographic vital rates and long term measures of occupancy (persistence) within territories. The resultant information will facilitate more precise differentiation between poor territories (sinks) and productive territories (sources). Improving the resolution in habitat state between the existing habitat models will provide more effective management for the species and possibly other old mixedwood habitat associates. 3.3 Habitat Management Maintaining blocks of high quality mature forest where there are abundant snags for nests will ensure availability of suitable habitat for barred owls. Such habitat must be managed in a spatially explicit manner and retention targets and forest management planning should reflect this. If habitat models are used to ensure that contiguous tracts of intact forest are retained for barred owl management purposes, the spill-over effects for other old mixedwood dependent wildlife species will also be realized. It is important to note that although the maintenance of snags and old poplars is vital for ensuring suitable nesting structures for barred owls, it will not be effective without proper landscape management. In other words, managing nesting structures 6
will only be successful at maintaining owls on the landscape if the larger landscape (required for foraging and cover) is maintained in suitable condition for the barred owl. Habitat management must address the succession of stand types and management practices across time and therefore is best achieved through the incorporation of industrial recommendations into long-term plans (see section 3.4). 3.4 Industrial Recommendations 3.4.1 Forestry: Without proper planning, forestry activities can severely deplete and damage barred owl habitat by increased fragmentation, loss of nest trees and inappropriate retention strategies. Any harvest clearing that does occur within older forested habitats should use mitigation strategies with the goal of retaining important habitat features for barred owls when the harvested forest regenerates. These operational mitigation items include (but are not limited to) the following: • Timing of Harvest Activities should aim to avoid critical nesting and fledgling periods (March 14 to July 15). • Within-block retention should aim to retain the integrity of large diameter snags and decadent poplar overstory trees >34dbh. These trees and snags could again become valuable nesting structures when the adjacent forest regenerates. In addition, unmerchantable timber (e.g. birch, small aspen, and small spruce) should be retained if they are adjacent to large balsam trees or snags being retained. Larger clumps or patches of trees adjacent to larger trees and snags will be more likely to provide nesting habitat. • Roads should be temporary in nature, in order to ensure reduced risk of road mortality in the future and reduced fragmentation of the habitat when the adjacent forest regenerates. Although stand level mitigation (as outlined above) is an important tool in management, landscape level harvest strategies that address habitat composition (i.e. amount) and configuration (i.e. fragmentation) will be key in ensuring long term persistence of barred owl populations. To effectively identify the amount and patterns of suitable habitat required for barred owls on the landscape, barred owl habitat models are being developed by Wildlife Management staff in cooperation with the Forest Management Branch of Environment and Parks. The following recommendations are in place to ensure that barred owls are considered at the landscape level in relation to forest management: • At the Forest Management Planning stage, an analysis of barred owl habitat should be incorporated into the planning process. A suggested method to complete this task is to use the most relevant barred owl model for the FMA in question (this can be determined in consultation with the Wildlife Biologist and Forest Management Branch staff) and model barred owl habitat availability at the scale of the home range for each scenario run of the Spatial Harvest Sequence and Timber Supply Analysis. The outputs should be compared with each other and with the pre-harvest landscape conditions to evaluate impacts of the proposed landscape level harvest plan on barred owls. 7
3.4.2 Oil & Gas, or other industrial developments: Oil and gas development can impact barred owls by causing loss and fragmentation of habitat (at the landscape scale), loss of nest trees, and road associated mortalities. The alignment of infrastructure (road, pipeline, well pad clearance) should favour younger stands and avoid old mixedwood stands where possible. All new infrastructure should follow the policies outlined in the Enhanced Approval Process Integrated Standards and Guidelines (EAPISG), available on the Environment and Parks website) (e.g. no roads should be constructed to parallel each other within 250m). Known nest sites, or those discovered during a wildlife sweep (See 100.8.1 in the EAPISG) should be buffered a minimum of 100m and up to 500m depending on the level of activity and timing (see EAPISG). A pre-development survey is recommended to identify any old snags or large poplars that have high nesting potential for owls, so that they can be avoided by the development if disturbances are planned within an area of old forest (guidelines for conducting essential habitat surveys for boreal raptors are provided in the ESRD Sensitive Species Guidelines 2013). Reclamation of well pads and roads in suitable stands should avoid seeding and instead implement planting of the composition of surrounding cover types. 3.4.3 Agricultural development: Agricultural development within suitable barred owl habitat should be minimized to prevent habitat loss and land conversion that favours species that prey on or compete with barred owl (e.g. great horned owls), and to avoid cattle knocking over standing dead trees that are important for nesting. Range improvements (e.g. clearings, dugouts) should be avoided near old mixedwood forest stands, where possible. If grazing occurs near barred owl habitat, provide attractants (e.g. salt blocks, water) and shade for cattle away from the forest edge or fence out old mixedwood areas. Strategies to prevent cattle from rubbing against the structure should be implemented when a nest site is identified. For example, fencing off a buffer zone around the nesting tree may provide sufficient protection for nesting barred owls. 3.5 Education and Communication Barred owls are an important indicator species for boreal forest health, and maintaining their habitat results in the persistence of habitat for numerous other species as well. Sharing this information through education and stewardship programs for stakeholders and the general public will greatly benefit conservation of habitat and ensure species resiliency. Stewardship programs should emphasize the challenge of balancing the many interests associated with old mixedwood forest management in the boreal and foothills regions. Citizens should be engaged through public outreach about the value of this sensitive species and the role they play in the boreal forest. Environmental consultants, oil and gas employees and forestry employees need to have access to tools that will help identify barred owl nest sites and breeding habitat to ensure they are properly identified, located, and mapped. With this in mind, an educational brochure has been created by Environment and Parks, in cooperation with the Alberta Forest Products Association. This brochure is available through the Alberta Forest Products Association offices and most Fish and Wildlife offices within forested regions of Alberta. 3.6 Regulation and Policy Barred owls are a protected species under Alberta’s Wildlife Act. In addition, as a Species of Special Concern in Alberta, there is a higher degree of interest in ensuring that monitoring activities and actions to maintain habitat are closely evaluated into the future. The status of 8
barred owls in Alberta should be reviewed regularly (as part of the Species at Risk Program) to ensure that, if populations are determined to be in further decline, actions are taken to appropriately amend status and policy in relation to this species. The Land Use Framework is a significant government initiative that has the ability to set objectives and track biodiversity indicators. It is important that as these Landuse Framework plans developed throughout the forested regions of the province, barred owls are included in planning either indirectly (through habitat targets for old mixedwood obligate species) or directly (through setting targets specific to barred owls and monitoring these indicators over time) to ensure that barred owl populations persist on the landscape into the future. Policies are presently in place to ensure that Forest Management Planning captures non-timber values through the Forest Management Planning process and creation of VOITs (Values, Objectives, Indicators, and Targets) to track these commitments. In many recent plans, barred owl habitat has been selected as a key habitat feature to track in order to meet non-timber objectives for old mixed wood obligate species. Work should continue to ensure that planning documents, as part of the Forest Management Planning process used by companies across the province, capture barred owl habitat either directly or indirectly. 4.0 SUMMARY As a species that nests in cavities within older boreal forest landscapes, the long term persistence of barred owl populations in Alberta is highly dependent on maintenance of old mixed-wood forest and the structure within. Industrial activities such as forest harvesting and oil and gas development threaten suitable barred owl habitat through either direct removal of old mixed- wood habitat and/or fragmentation of the landscape. To manage for this species into the long-term, key action items to pursue as part of this management plan include: • Assurance that monitoring programs can adequately track trends in barred owl populations. • Assurance that research and monitoring programs focus on gaps in data in the North East and North West portions of Alberta, as well as focus on demographic performance in alternate habitat areas (determining source/sinks) • Assurance that old mixed-wood forests are maintained on the landscape through Forest Management Planning initiatives, stand-level mitigation associated with forest management activities, and pre-planning/mitigation for oil and gas activities. • Assurance that educational materials are made available to the public and private sectors to ensure that that individuals working and recreating in barred owl habitats are aware of the important features for this species. Monitoring and research initiatives will need to inform policy and regulations into the future. If barred owl populations are seen to decline over time, then more aggressive landscape planning and legislation will be required to ensure that habitat is maintained for this species for future generations of Albertans to appreciate. 9
5.0 LITERATURE CITED Alberta Sustainable Resource Development. 2010. The general status of Alberta wild species 2010. Alberta Sustainable Resource Development, Fish and Wildlife Service, Edmonton. URL: http://www.srd.alberta.ca/FishWildlife/SpeciesAtRisk/GeneralStatusOfAlbertaWildSpecies/Defa ult.aspx. Alberta Sustainable Resource Development. 2008. Report of Alberta’s Endangered Species Conservation Committee: June 2006. Alberta Sustainable Resource Development, Fish and Wildlife Division, Edmonton AB. 44 pp. Alberta Sustainable Resource Development. 2005. Status of the barred owl (Strix varia) in Alberta. Alberta Sustainable Resource Development, Fish and Wildlife Division, and Alberta Conservation Association, Wildlife Status Report No. 56, Edmonton, AB. 15 pp. Alberta Environment and Sustainable Resource Development. 2013. Sensitive Species Inventory Guidelines. April 2013. http://esrd.alberta.ca/fish-wildlife/wildlife-management/sensitive-species- inventory-guidelines.aspx Alberta Environmental Monitoring, Reporting and Evaluation Agency. 2015. Validating Barred Owl Habitat Models for the Oil Sands Monitoring Region of Alberta. July 2015. Beaverhill Bird Observatory. Nocturnal Owl Monitoring Survey. http://www.beaverhillbirds.com/owl_surveys.php Accessed on January 7th, 2013. Fisher, J. T., B. Eaton, and D. A. Kirk. 2009. Species-at-risk indicator habitat model: Barred Owl (Strix varia), Lower Athabasca Regional Plan. Alberta Research Council Inc., Vegreville, Alberta. Grossman, S. R. 2003. Owl responses to habitat change at the landscape and regional scale and effects of weather in east central Alberta. MSc. thesis. University of Alberta (Canada). Mazur, K. M., and P. C. James. 2000. Barred Owl (Strix varia). The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North American online: http://bna.birds.cornell.edu/bna/species/508 Olsen, B. T. 1999. Breeding habitat ecology of the barred owl (Strix varia) at three spatial scales in the boreal mixedwood forest of north-central Alberta. MSc. thesis, University of Alberta (Canada). Olsen, B. T., S. J. Hannon, and G.S. Court. 2006. Short-term response of breeding barred owls to forestry in a boreal mixedwood forest landscape. Avian Conservation and Ecology 1:1. [online] URL: http://www.ace-eco.org/vol1/iss3/art1. Piorecky, M. D. 2003. Distribution, abundance and habitat selection of northern pygmy and barred owls along the eastern slopes of the Alberta Rocky Mountains. MSc. thesis. University of Calgary (Canada). Priestley, L.T. 2004. The barred owl, Strix varia in Alberta: distribution and status. Canadian Field Naturalist 118 (2): 215-224. 10
Russell, M. S. 2008. Habitat selection of barred owls (Strix varia) across multiple spatial scales in a boreal agricultural landscape in north-central Alberta. MSc. thesis. University of Alberta (Canada). Takats, D. L. 1998. Barred owl habitat use and distribution in the Foothills Model Forest. MSc. thesis, University of Alberta (Canada). 11
List of Titles in the Alberta Species at Risk Conservation Management Plan Series (as of February 2016) No. 1 Long-toed Salamander Conservation Management Plan. No. 2 Sprague’s Pipit Conservation Management Plan, 2010-2015. No. 3 Long-billed Curlew Conservation Management Plan, 2010-2015. No. 4 Harlequin Duck Conservation Management Plan, 2010-2015. No. 5 Weidemeyer’s Admiral Conservation Management Plan, 2012-2017 No. 6 Western Small-footed Bat Conservation Management Plan, 2012-2017 No. 7 White-winged Scoter Conservation Management Plan, 2012-2017 No. 8 Bull Trout Conservation Management Plan, 2012-2017 No. 9 Prairie Falcon Conservation Management Plan, 2012-2017. No. 10 Black-throated Green Warbler, Bay-breasted and Cape May Warbler Conservation Management Plan, 2014-2019. No. 11 Great Plains Toad Conservation Management Plan, 2015-2020. No. 12 Prairie Rattlesnake Conservation Management Plan, 2015-2020. No. 13 Hare-footed Locoweed Conservation Management Plan, 2016-2021. No. 14 Barred Owl Conservation Management Plan, 2016-2021.
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