Species analysis
Statistical exploration
Classification trees
Variables
Redhead
Occurred the most disproportionately in hexagons with more than 4%
wetlands and wet shrubland and less than 6% recently cutover/burnt
forest and any area of lakes/reservoirs. Somewhat less likely where
less wetlands and wet shrubland, but present if July maximum
temperature (hex. avg.) is more than 26� C and June minimum
temperature (hex. med.) is more than 8� C. Also occurred in eastern
Oregon hexagons without wetlands and wet shrubland if some other
freshwater habitat is present. The logistic regression analysis showed
positive or negative association with lakes/reservoirs, wetlands and wet
shrubland, Douglas-fir - w. hemlock - red cedar forest, elevation (hex.
avg.), April minimum temperature (hex. max.), topographic variation,
and-to a lesser degree-road density, the extent of public land, and
June minimum temperature (hex. avg.).
Classification trees
Hexagons: using ONHP land cover classification (accuracy score: 88.14)
Squares: using ONHP land cover classification (accuracy score: 96.61)
Hexagons: using AVHRR land cover classification (accuracy score: 83.49)
