Habitat selection in the yellow-breasted chat

Abstract

During the spring and early summer of 1978, boundaries were determined for 19 yellow-breasted chat (Icteria virens) territories in southwestern Virginia. The gross structural characteristics of the vegetation found within these areas were analyzed. Each vegetation variable was regressed against territory size and against a measure of chat density. It was assumed that both smaller territories and territories having a greater number of territories surrounding them contained better quality habitat. Chats appear to choose their habitat on the basis of the total brushiness present. of several different components. This value may result from the summation In this study, bramble (Rubus spp.) cover and total shrub cover were the two major components involved. The vegetation contributing to the total brushiness value should minimally provide about 25% cover and average about 0.75 min height. Increased greenbrier (Smilax spp.) cover is associated with better quality chat habitat. Presumably, it is indicative of the types of vegetation, such as thickets and open woods, which are characteristic of chat habitats. However, the measure of greenbrier cover seems limited in its ability to distinguish preferred chat habitat. Chat territories may include wooded areas provided there is a fairly dense growth of vegetation below about 1.5 m. Generally, this situation would occur only in a woods with a reasonably open canopy. If only an edge of a woods bordering a brushy field is involved, side-lighting may be sufficient for the growth of ground-level vegetation, even if under fairly dense overstory vegetation.