In Arizona's low deserts, the invasive European Starlings compete with our native woodpeckers--Gilded Flickers, Gila Woodpeckers, and Ladder-backed Woodpeckers--for nesting cavities. The starlings outcompete the the latter two species, but the slightly larger Gilded Flickers hold their own, and "knives drawn" aerial battles such as this one, while not uncommon, are wildly interesting.