Species analysis
Statistical exploration
Classification trees
Variables
American Goldfinch
Occurred the most disproportionately in hexagons with elevation (hex.
avg.) less than 975 ft. and less than 2%. of Douglas-fir and Port Orford
cedar forest. Somewhat less likely to occur at elevation (hex. avg.) of
975-1333 ft., and then mainly if there is little hexagon variation in the
maximum May temperature. Occurred above 1333 ft. (in hexagons
with an elevation [hex. avg.] of up to 2002 ft.) mostly where there are
more than 56 mi. of stream per square mile. The logistic regression
analysis showed positive or negative association with elevation (hex.
avg.), stream density, April minimum temperature (hex. avg.), July
minimum temperature (hex. min.), the extent of public land, and-to a
lesser degree-April precipitation (hex. med.) and towns and cities.
Classification trees
Hexagons: using ONHP land cover classification (accuracy score: 84.19)
Squares: using ONHP land cover classification (accuracy score: 84.64)
Hexagons: using AVHRR land cover classification (accuracy score: 85.35)
