Use & Availability of Habitats & Foods Resource selection Measurements of use & availability –Food –Habitat Design & analysis Modeling Sampling
Use & Availability of Habitats & Foods Understanding use, availability, selection, and limiting factors –Management & conservation
Use & Availability of Habitats & Foods Resource selection or preference –Resource unit? –Use v. availability Importance?
Wildlife Habitat Habitat selection –Use –Availability Quantity Accessibility Digestibility (food) –Selection –Density as a misleading indicator of habitat quality (Van Horne 1983) Vegetation Association % Use% AvailableSelection Field5060- Forest35 0 Wetland155+ Total100
Use & Availability of Habitats & Foods Levels of selection & effects of scale –Management implications Spatial & temporal scales
Wildlife Habitat Levels of selection & scale –Food, water, cover, & space A hierarchical process involving a series of innate & learned behavioral decisions made by an animal about what habitat or habitat components it would use at different scales of the environment –Microhabitat, macrohabitat, & landscape
Wildlife Habitat Levels of selection & scale (Johnson 1980) –First-order Physical or geographic range (landscape level habitat) –Second-order Home range within geographic range (landscape or macrohabitat) –Third-order Use of habitat components within home range (macrohabitat) –Fourth-order Procurement of a third-order habitat component from those available at that site (microhabitat)
Wildlife Habitat Levels of selection & scale for ruffed grouse –First-order Sauer, J. R., J. E. Hines, and J. Fallon The North American Breeding Bird Survey, Results and Analysis Version USGS Patuxent Wildlife Research Center, Laurel, MD
Wildlife Habitat Levels of selection & scale for ruffed grouse –Second-order
Wildlife Habitat Levels of selection & scale for ruffed grouse –Third-order e.g., edge
Wildlife Habitat Levels of selection & scale for ruffed grouse –Fourth-order e.g., this particular edge
Use & Availability of Habitats & Foods Levels of selection & effects of scale –Sampling & designs Researcher must consider scale of selection –Temporal »Daily, seasonal, etc. –Spatial »Resolution (grain) - Landsat image v. ground mapping »Extent (size)
Use & Availability of Habitats & Foods Selection – Sampling & designs Used v. unused Used v. available – Is there a difference?
Use & Availability of Habitats & Foods Levels of selection & effects of scale – Sampling & designs General designs differ depending on whether or not selection of units by individual animals can be identified and whether or not resource units are defined to be available to the population of animals or individuals – Designs I, II, & III » Johnson’s level of selection?
Use & Availability of Habitats & Foods Selection – Sampling & designs Design I – Used, unused, or available resource units are sampled or censused for the study area and use by the population of animals is recorded
Use & Availability of Habitats & Foods Selection – Sampling & designs Design II – The study area (availability) is defined for a population of animals, but individual animals are identifiable and resource units selected are recorded for individual animals
Use & Availability of Habitats & Foods Selection – Sampling & designs Design III – Individuals are uniquely identified for resource unit use and availability
Use & Availability of Habitats & Foods Selection – Sampling & designs: comparison Design I – Most commonly used in the past – Least specific info. Designs II & III – More specific info.: sex, age, etc. – More costly (e.g., radio-telemetry) – More assumptions » Random/representative sample » Independence of samples (locations and animals) – Territorial v. non-territorial species?
Use & Availability of Habitats & Foods Resource selection functions (RSF) –Models predicting the relative probability of selection of different resource units among those available Based on use v. availability
Use & Availability of Habitats & Foods Measuring resource use & availability –Techniques: use Direct –Observation –Capture –Radio-telemetry Indirect –Tracks –Scat –Evidence of feeding
Use & Availability of Habitats & Foods Measuring resource use & availability –Techniques: availability Mapping –GIS »Landsat, aerial photographs, ground, etc. - resolution Random or systematic sampling of sites –Johnson’s levels –Design type (I, II, or II)
Use & Availability of Habitats & Foods Design considerations & analyses –General Sample size Representative sample Quality –Census, survey/sample, index
Use & Availability of Habitats & Foods Design considerations & analyses –Standard analyses E.g., t-test/ANOVA –Used vs. available/unused Vegetation Association Use ( ± SE) Available ( ± SE) P Field Forest Wetland
Use & Availability of Habitats & Foods Design considerations & analyses –Chi-square analyses
Use & Availability of Habitats & Foods Modeling resource selection –Logistic regression –Log-linear modeling –Discrete choice models –Compositional analysis –Others
Vegetation Sampling & Measurement Initials steps –Develop objectives Sampling: what, when, and where –General aspects of vegetation and other components Species composition Spatial distribution –Vertical & horizontal Temporal variations Stand & landscape structure –Study site selection
Vegetation Sampling & Measurement Preparation & getting started –Leadership –Initial planning Time, labor, and cost considerations
Vegetation Sampling & Measurement Techniques –Next class
Vegetation Sampling & Measurement Multiple scale surveys
Vegetation Sampling & Measurement Applications of measurement –See examples in chapter 20 Proper inference