The effect of understory foliage density on American Redstart (Setophaga ruticilla) distribution near Douglas Lake.

Abstract

This study investigated whether there is a correlation between American Redstart (Setophaga ruticilla) density and foliage density in a deciduous forest on Douglas Lake, Michigan. Birds were counted by observing and listening to American Redstarts as they sang early on four mornings at ten selected points in this forest. At the same ten points, understory foliage density was scored. A linear regression and scatter plot with a best fit line calculated by SPSS revealed a significant positive correlation (R2 = 0.76) between the average number of American Redstarts at a given data collection point and its corresponding foliage density score, which supported the hypothesis that there would be more American Redstarts in areas with more foliage. This information can be used in maintaining the habitat of the American Redstart and related species.