Guenter Lamsfus - CBCN October 2007 page 166 to 167

It appears that taxonomy changes of the gulls of the argentatus / fuscus complex have become a never-ending story. In my paper pub­lished in Ceylon Bird Club Notes December 2006 (p.166-168) I wrote that the process might soon settle with two 'full' species of the group occurring as winter visitors to Sri Lanka: the dark-backed Heuglin's Gull Larus heuglini and the grey-backed Steppe Gull L. barabensis.

Now the situation is about to change again. In the latest issue of Ibis (Vol.149: 853-857) the British Ornithologists' Union makes new taxo­nomic recommendations, largely based on genetic findings (mtDNA), which "better reflect recent advances in knowledge of the evolution and systematics of large gulls". The results are as follows.

- Caspian Gull L. cachinnans (monotypic)
- Lesser Black-backed Gull L. fuscus with subspecies fuscus, inter- medius, graellsii, heuglini, taimyrensis, barabensis- American Herring Gull L. smithsonianus with subspecies smithson- ianus, vegae, mongolicus
- Yellow-legged Gull L. michahellis with subspecies michahellis, atlantis
- Armenian Gull L. armenicus (monotypic)
- Herring Gull L. argentatus with subspecies argentatus, argenteus.

Only one species of this group visits Sri Lanka, i.e. the Lesser Black-backed Gull L. fuscus in the two races heu­glini and barabensis, the lat-ter of which is grey-, not black-backed.

In principle this is equivalent to the taxonomy of Rasmussen & Ander­ton in their Birds of South Asia: the Ripley Guide (2005) except for the use of the taxon fuscus instead of heuglini. Now it remains to be seen whether or not this will generally be accepted. For the time being the taxonomy of these two authors may be used although a defi­nite change to the B.O.U. recommendations could be expected in the near future.

In this connection, I would like to submit an addendum to my paper of December 2006.

In Volume 2 of Birds of South Asia Rasmussen describes the Steppe Gull as uncommon in Sri Lanka, with "few if any definite records". At this point it must be recalled that any grey-backed gull of the present group recorded in Sri Lanka was designated until the 1990s as Herring Gull L. argentatus, and then as Yellow-legged Gull L. cachinnans, later and newly called Caspian Gull. Currently we believe that it is the Steppe Gull L. h. barabensis which visits the island.

Over the years, the number of records in Sri Lanka of these grey-backed birds has indeed been low and - to my knowledge - there are only a few specimens of immatures classified as L. argentatus in the Colombo Museum, still awaiting re-examination. Based on records from west and south India where barabensis has been clearly identified and occurs in greater numbers during winter it must be assumed that grey-backed gulls of this group seen in Sri Lanka belong to the same form.

In Sri Lanka both forms, heuglini and barabensis are mainly met with along north-eastern and northern coasts and off-shore islands, the for­mer more or less regularly and sometimes in large numbers, the latter only occasionally and very sparsely.