Inventory of landbirds in San Juan Island National Historical Park tabular data, 2002.

The Institute for Bird Populations (IBP) collaborated with personnel at San Juan Island National Historical Park to initiate a Park-wide inventory of landbirds. The goals of the inventory were to estimate habitat-specific density and park-wide abundance for a large suite of species, and to produce information that will assist park managers and cooperators in designing the park's long-term landbird monitoring program.

We used variable circular plot point counts to describe avian presence and abundance at specific points in a parkwide grid pattern. We recorded all species detected and the linear distance to each bird when first seen, date, time, and level of ambient noise. A journal was kept for each field day describing location (UTM coordinates), habitat type (cover type), and elevation. At each point, vegetation was sampled to describe habitat structure and composition within a circular 50 m radius plot centered at the point count survey point. Data from this rapid characterization included aspect, slope, vegetation cover (herbaceous, shrub, and tree), and densiometer readings recorded along 20 m transects in the 4 cardinal directions.