Cornell: “A large, assertive flycatcher with rich reddish-brown accents and a lemon-yellow belly, the Great Crested Flycatcher is a common bird of Eastern woodlands. Its habit of hunting high in the canopy means it’s not particularly conspicuous—until you learn its very distinctive call, an emphatic rising whistle. These flycatchers swoop after flying insects and may crash into foliage in pursuit of leaf-crawling prey. They are the only Eastern flycatchers that nest in cavities, and this means they sometimes make use of nest boxes.”