Andy's masterful summary of the long-running Iceland/Thayer's/Herring
(etc.) controversy illustrates the difficulties of sorting out
relationships among the gulls, and underscores the need for a *lot*
of new field, museum, and laboratory work on this complex. An
article by Phil Chu, published in the journal *Cladistics* in 1998
and summarized in a recent issue of *Dutch Birding* (21:207-218),
adds even more fuel to the speculative fire. Jon King elegantly drew
out the most startling of Chu's conclusions in a posting to the
Frontiers of Field Identification list last fall. Here is an excerpt
from his posting:

"The Chu paper presents a new phylogeny of 58 gull taxa using dozens
of plumage and skeletal characters. Although Chu's study appears to
be very sound, many aspects of his phylogenetic tree are poorly
supported, and hence should be treated with some caution until
verified by further work. A handful of the most intriguing
conclusions applicable to North America are:

"- Thayer's Gull is a valid species most closely related to
Glaucous-winged Gull, not to the Iceland Gull group. This is not a new
suggestion, but one that has received little credence in recent decades.
- Nominate Iceland Gull is the sister-taxon of Glaucous Gull. Kumlien's
Gull is more distantly related to both, with dark pigmentation
apparently being ancestral in this group of three species, having been
retained only by kumlieni.
- Kamchatka (kamtschatschensis) and Mew (brachyrhynchus) gulls are more
closely related to one another than to Common (canus) Gull. Given that
earlier studies suggest Kamchatka and Mew may be separate species, it
may now be appropriate that all three forms are considered valid
species.
- herring gulls from NE Asia (Vega) are not sister-taxa of American
Herring Gulls (smithsonianus). Unfortunately, Chu's study did not
include many other herring gull taxa, so relationships within the
Palearctic remain unclear.
- the Kelp (or Cape) gull of southern Africa (vetula) is not the
sister-taxon of the Kelp Gull (nominate dominicanus) of Australasia and
S America. The former does not even fall out among the dark-backed
gulls, but actually near a group that includes californicus.

"Those with a serious interest in issues of gull systematics and
identification will want to consult at least the DB summary, if not
the original work (though the former is more accessible, and is
lavishly illustrated with some superb photos)."

We should be grateful to gulls for their big contribution to making
the world an interesting place.

Hal Opperman
Medina, Washington
mailto:halop at accessone.com