Golden-cheeked Warbler (Dendroica chrysoparia: Parulidae) Territory and Non-territory Habitat Choice in Fragmented Ashe Juniper Patches on the Kerr Wildlife Management Area

Abstract

Golden-cheeked Warblers (Dendroica chrysoparia) use a variety of cues for selecting appropriate habitat. This study examined habitat variables associated with Golden-cheeked Warbler habitat choice in territories and non-territory areas in fragmented Ashe juniper (Jumperus ashei) patches on the Kerr Wildlife Management Area. The point-centered quarter method was used to gather vegetational data. Woody vegetational characteristics in both the canopy (> 1.5 m) and understory (< 1.5 m) in territory (n = 25) and non-territory (n - 25) areas were analyzed through stepwise (backwards) logistic regression. The normal approximation to the Mann-Whitney U test was used to examine differences between territory and non-territory areas. Canopy and understory statistics were handled separately. Differences in territory and non-territory areas were found to be a combination of woody plant structure and species composition. Territory areas had greater patch size, less total density of all plants, greater mean area per plant, and greater mean canopy coverage per plant in both the canopy and understory. Canopy in territories had fewer individual plants, a greater point-to-plant distance, less mean total canopy coverage for all species, and less mean total density than non-territory areas while territory understories had a greater number of plants, relatively equal pointto-plant distance, greater mean total canopy coverage for all species, and less mean total density than non-territory areas. The logistic regression model was tested for discrimination and calibration by ROC analysis mid the Hosmer and Lemeshow goodness-of-fit test.