Effect of landscape matrix type on nesting ecology of the Northern Cardinal
Spatial distribution of forests relative to other habitats in a landscape may influence nest success of songbirds. For example, nest predation in mature forests increases as the percentage of clear-cut land in the surrounding matrix increases (Yahner and Scott 1988). Blake and Karr (1987) noted that birds breeding in forest fragments may incorporate adjacent habitats, such as second growth forests, into their territories. In the southeastern United States, many hardwood 48 THE ORIOLE vol. 80 • 3 – 4 forests exist as small stands in association with extensive pine forests, the dominant forest cover in the region. Pine forests comprise about 28% of South Carolina’s land area (Tansey and Hutchins 1988). We tested the hypothesis that a pine forest matrix would function as a buffer, insulating birds in hardwood forests from the high nest predation and parasitism rates commonly recorded in truly isolated forests. We compared the nest success and nest-site selection of Northern Cardinals (Cardinalis cardinalis) in South Carolina hardwood forests enclosed by a matrix of either mature pine forest or agricultural fields.