Royal flycatcher

The royal flycatchers are a genus, Onychorhynchus, of passerine birds that the International Ornithological Committee (IOC) places in the family Tityridae.

Names
The genus name Onychorhynchus comes from the Greek words ὄνυξ onyx "nail" and ρυγχος rhynkhos "bill". The specific epithet of the type species, coronatus, and the common name royal flycatcher, refer to the striking, colorful crest, which is seen displayed very rarely, except after mating, while preening, in courtship as well as being handled.

Taxonomy and systematics
For many years the IOC and BirdLife International's Handbook of the Birds of the World (HBW) placed four species in genus Onychorhynchus. In 2024 the IOC combined ("lumped") the northern, Amazonian, and Pacific royal flycatchers as a single species, the tropical royal flycatcher (O. coronatus), leaving the Atlantic royal flycatcher unchanged.

However, the taxonomies of the genus and of the family Tityridae are unsettled. HBW retained the four-species treatment. The Clements taxonomy rocognizes the same two species of royal flycatcher as the IOC. However, Clements places them, four other species, and the sharpbill (Oxyruncus cristatus) in family Oxyruncidae, rather than in Tityridae like the IOC. The North American and South American Classification Committees of the American Ornithological Society (AOS) treat genus Onychorhynchus as having one species, the royal flycatcher (O. coronatus sensu lato), with multiple subspecies. The AOS committees place the sharpbill by itself in family Oxyruncidae, and place the royal flycatcher and the same four additional species as Clements in family Onychorhynchidae. The South American committee is seeking a proposal for reevaluation of the taxa.

The IOC and Clements recognize these two species in genus Onychorhynchus.