Caspian Gull - Classification and Subspecies

Classification and Subspecies

This form has a troubled taxonomic history, summarised in the Herring Gull article. The Caspian Gull used to be treated as a as a subspecies of the Herring Gull but it is now treated as a full species by many authorities (e.g. the British Ornithologists' Union Records Committee). Some authorities include the Yellow-legged Gull (L. michahellis) within L. cachinnans but it is now commonly considered to be a separate species.

The Steppe Gull or Baraba Gull (L. (cachinnans) barabensis) may be regarded as a subspecies of the Caspian Gull or as a separate species. It is also very similar genetically to its northern neighbour, the taimyrensis race of Heuglin's Gull. The Steppe Gull breeds in Central Asia, particularly northern Kazakhstan. Its non-breeding range is still little-known but most are thought to winter in south-west Asia from the Persian Gulf to north-west India. There are possible records of this form from Hong Kong and South Korea.

The Mongolian Gull (L. (vegae/cachinnans) mongolicus) may be classed as a subspecies of the Caspian Gull, a subspecies of the East Siberian Gull or as a species in its own right. It breeds in Mongolia and surrounding areas and migrates south-east in winter.

• Young Caspian Gulls in Poland