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NORTHERN SPOTTED OWL (Strix occidentalis caurina)

Appendix 2

Preliminary List of Research Topics

Broad TopicsInformation Gaps for Decision ProcessSpecific Research TopicsaType of Studyb
   
POPULATION  
Demography / trends  
 RangeDistribution relative to known range as index of healthInventory (appropriately designed)
    
  Pattern of distribution in the landscape at different spatial scales, e.g., international and regional (metapopulations, U.S. comparison; subpopulations for local)Assess existing information / literature, and database gathering
 AbundanceIndex of number of animals (animals or habitat [ha] over time)Inventory and research
 Quality of populationProportion of breeders and non-breeders, and age-specific issues 
 Population parametersSurvivorship, natality, immigration/emigration 
  Dispersal distances 
Genetic profiling  
 Measure of variabilityRelative to southern populations 
  Relative to ecosystem types 
 Identification of individualsPopulation tool to track lineage 
  Population tool to estimate population size 
Population modeling / trends  
 Population viabilityMinimum number of breeders and distribution to sustain population over time 
  Minimum spatial distribution of breeders 
  Population projections for management decisions 
   
HABITAT  
Features of habitat (topography, vegetation, forest structure) 
 Nesting habitatDescribe nest trees 
  Describe nest patches (immediate proximity to nest) 
  Describe nest stands (area of similar habitat type immediately surrounding the nest patch) 
  What is the availability of type A and B suitable habitats, and within-stand variation of these habitats? 
 Home range (nesting / foraging)Describe area used/selected during breeding period (area most used by adults [male] while young in nest) 
  Describe post-fledging area used (i.e., before juvenile dispersal) 
  Describe overwintering area used (i.e., after young disperse) 
  What area of habitat must be suitable in a home range (e.g., 67%) and how should it be distributed? 
Dispersal habitat  
 Habitat-specific survivorshipDo SPOW juveniles have higher survivorship in some habitat types? 
 Selection of habitatWhat habitats are selected by juveniles for dispersal? 
 BarriersAre young forests, roads, lakes, ridges, etc., barriers to juvenile dispersal? 
Modeling habitat  
 Suitability / capabilityAmount and availability over time at different population levels 
  Change in habitat availability over time with natural disturbance (fire) 
  Connectivity of habitat 
  Fragmentation (patch size, distribution, and connectivity) 
   
PREY  
Population  
 Abundance and distributionAvailability of prey relative to different spatial criteria (e.g., broad ecosystem, stand/forest type, geographic region, and SPOW habitat) 
  Is prey availability limiting SPOW survival? 
  Does the importance of flying squirrels and bushy-tailed wood rats in diet differ by ecosystem? 
 Population trendsRelative to weather, food availability 
 Ecology of preyPrey habitat 
  Prey breeding requirements 
  Prey foraging requirements 
  
PREDATORS / COMPETITORS (niche overlap) 
Barred Owl (BDOW)  
 PopulationTrends in BDOW population 
  How does adult and juvenile survivorship and dispersal for BDOW differ from SPOW? 
  Do BDOW breed with SPOW?  Under what conditions? 
 HabitatDo BDOW select wetter ecosystems (thus distribute differently in the landscape) than SPOW? 
  What are features in nesting and home range habitat of BDOW? How do they compare to SPOW? 
  Do BDOW move seasonally and does this change how they might overlap SPOW habitat 
  What is home range size of BDOW 
  What habitats do BDOW select for foraging in the landscape? Does they differ by ecosystem, or overlap with SPOW habitat requirements? 
  Does the BDOW population now saturate available habitat? 
 PreyWhat are prey of BDOW? How do relative proportions in the diet compare to those reported for SPOW? 
 BehaviourDoes BDOW behaviour change when overlapping home ranges of SPOW? 
Great Horned Owl (GHOW)  
 PopulationWhat is the density of GHOW in coastal ecosystems? 
 HabitatHow are GHOW distributed in the landscape compared to SPOW? 
  Where do GHOW forage and does this present high risk to SPOW? 
 PreyWhat is diet of GHOW? 
Other predators  
 TypeWhat are other potential predators of SPOW? 
 HabitatWhat habitats do these predators generally forage within? 
   
HABITAT ENHANCEMENT  
Foreststructure  
 Stand conversionCan unsuitable habitats for breeding and/or foraging be converted to suitable within home ranges? 
 Recruitment of younger standsCan stand development be accelerated so suitable stands are grown in less than average years? 
  Can stand structure (e.g., snags, vertical and horizontal complexity, large branches) be created? If so, how long does this take? 
 Landscape connectivityCan stands be enhanced to provide connectivity for dispersal? 
Prey  
 AbundanceCan abundance or density of prey be increased using alternative systems to enhance prey forage or nesting/denning habitat? 
   
HABITAT MAINTENANCE  
Foreststructure  
 Stand-level operationsCan alternative silvicultural systems be applied that do not reduce habitat quality short term/long term? 
 Landscape patternsCan landscapes be altered while maintaining dispersal habitat? 
Prey  
 AbundanceWill retention of legacy stands help maintain prey abundance when silvicultural systems are applied to adjacent stands? 

aStudy questions.

bFor example, inventory, monitoring, research, or adaptive management.