The ability of songbirds to survive and reproduce depends on many factors, one of which is the ability to acquire enough food. We quantified foraging behavior, nestinghabitat vegetation composition, and available arthropod prey of the Vireo atricapilla (Black-capped Vireo) in Texas during 2010 and 2011. We used observational surveys of foraging behavior and vegetation time-use to quantify the Black-capped Vireos' foraging behavior and vegetative use versus availability (i.e., mean proportion of use vs. vegetative species availability). We collected descriptive data on the Black-capped Vireos' foraging use of available vegetative species and compared among vegetative species, year, and within-season sampling periods. In 2010 and 2011, we identified and mapped 49 and 63 breeding territories and repeatedly surveyed 30 and 58 territories for foraging activity, respectively. Data analysis focused on the foraging use of the 3 most commonly used and available tree species: Juniperus ashei (Ashe Juniper), Quercus sinuata (Shin Oak), and Q. fusiformis (Live Oak). Ashe Juniper, Shin Oak, and Live Oak together made up 78.8% and 83.6% of total proportion of substrate for foraging efforts in 2010 and 2011, respectively. Ashe Juniper had the highest proportion (~28–50%) of foraging effort in 2010, 2011, and all but 1 sampling period for both years. We also repeatedly collected branch clippings from within a random subset of surveyed Black-capped Vireo territories to identify potentially available arthropod foods. We evaluated by order richness, total abundance, and dry biomass to make comparisons among vegetative species, year, and within-season sampling periods. We found significant differences in the biomass of arthropod orders Acari and Thysanoptera in 2010 and between orders Acari and Hymenoptera in 2011 among the 3 focal vegetative species. Examination of additional descriptive data suggests seasonal changes in potentially available arthropod foods. Our research underscores the importance of vegetation composition to Black-capped Vireos that may help habitat managers select for potential vegetative species distributions to optimize food resources throughout the breeding season for this species.