Thanks for the question, Mary.

After many years of debate, the AOS (American Ornithological Society) in 2017 moved the Yellow-breasted Chat (Icteria virens) to the Icteriidae family. It is the only member of this family…..(NOT many bird species are an “only child” in their own family in N. America.)

As you may know, this seven-inch songbird was once a member of the New World warbler family (Parulidae)

The reorganization does not end the controversy among researchers. Several still believe blood analysis suggests the chat should remain in the Parulidae. In my view, they are NOW in the minority opinion, yet remain steadfast that the traditional Biological Species Concept (based on song/call expressions; behavior; skull/anatomical features) should, thus, persist……as the taxonomical organization device for separating the world’s bird species into orders and families (e.g., Parulidae, Icteriidae, etc…..There’s ~262 families in the world.)