Long-tailed Tit - Taxonomy

Taxonomy

The Long-tailed Tit was first classified as a true tit of the Parus group. Parus has since been split from the Aegithalidae, becoming a distinct family containing three genera:

• Aegithalos (long-tailed tits), five species including A. caudatus
• Psaltria (Pygmy Bushtit), monotypic
• Psaltriparus (American Bushtit), monotypic.

This is the only representative of the Aegithalidae in northern Eurasia. The Long-tailed Tit exhibits complex global variation with 19 races recognised, divisible into four groups:

• the caudatus group in northern Europe and Asia. A. c. caudatus has a pure white head
• the europaeus group in southern and western Europe, north-east China, and Japan. Separating rosaceus from other members of the Europaeus group though is problematic, relying on varying thickness of the crown stripes and amount of streaks and colour on the underparts
• the alpinus group in Mediterranean Europe and south-west Asia.
• the glaucogularis group in China.

Where the groups meet there are extensive areas occupied by very variable ‘hybrids’. The British Long-tailed Tit, subspecies rosaceus, belongs to the europaeus group. Biochemical evidence has shown Aegithalidae to be closely related to the babblers.