Yellow-breasted Chat

Chats (formerly sometimes known as "chat-thrushes") are a group of small Old World insectivorous birds formerly classified as members of the thrush family (Turdidae), but following genetic DNA analysis are now considered to belong to the Old World flycatcher family (Muscicapidae).
The name is normally applied to the more robust ground-feeding flycatchers found in Europe and Asia and most northern species are strong migrants. There are many genera and these birds in particular make up most of the subfamily Saxicolinae.
Other songbirds called "chats" are:

Australian chats, genera Ashbyia and Epthianura of the honeyeater family (Meliphagidae). They belong to a more ancient lineage than Saxicolinae.
American chats, genus Granatellus of the cardinal family (Cardinalidae), formerly placed in the wood-warbler family. They belong to a more modern lineage than Saxicolinae.
Yellow-breasted chat (Icteria virens), an enigmatic North American songbird previously placed in the wood-warbler family (Parulidae) and now in the monotypic Icteriidae; its true relationships are unresolved.