Ornithology, Evolution, and Philosophy 123

328 10 Systematics and Classification
His global macrotaxonomic knowledge of several songbird families enabled
Mayr (1955b) to comment critically on published studies of songbird phylogeny
evaluating the methods and principles of the respective authors. He agreed with
the separation of the Chaffinch (Fringilla coelebs) from the Carduelinae and recommended
for it a separate subfamily Fringillinae within the Fringillidae because
of this species’ cardueline resemblance in plumage coloration and bill structure,
in gape color of the nestling and the finely woven nest (see also Mayr 1956e).
James L. Peters’ Check-list of Birds of the World (16 volumes, 1931–1987, including
the index volume) is the most complete survey of all bird taxa that have been
described down to the subspecies level giving complete synonymies for all taxa
described. It was basically a list of subspecies until Ernst Mayr took over editorship
in 1953 (volumes 8–15) and “reintroduced,” so to speak, the species as a unit
symbolized by a binominal heading of the list of subspecies for each species taxon.
The work had been started by J. L. Peters, curator of ornithology at the Museum
of Comparative Zoology (Harvard University), in the late 1920s and the first seven
volumes had been published, when he died in 1952. Mayr’s appointment as an
Alexander Agassiz Professor in 1953 initiated his coeditorship of the Check-list
with J.C. Greenway, curator of ornithology. The overall plan for the continuation
of the work was Mayr’s, who asked numerous colleagues to participate as authors
of particular families. Some of the larger families were treated by several authors
(Bock 1990).
Ever since he arrived in New York in January 1931, Mayr had helped Peters with
the first volumes of the Check-list. Writing to Stresemann on 7 May 1931 he stated
(transl.):
“Tomorrow I travel to Boston to work with Peters. His Check-list is fine and
I admire how well he knows the new literature. I need to correct only very little
regarding New Guinea and the Solomons. This is the more surprising since he
is so little specialized in this region where Mathews makes work so difficult for
every non-specialist. I have the impression that the Check-list is an extraordinary
achievement. Of course, the American influence is noticeable with respect to the
delimitation of genera and species.”
Mayr’s first task in 1953 after arriving at Harvard was to develop a classification
and sequence for the families of passerine birds to be treated in the eight remaining
volumes (regarding the difference between a classification and a linear sequence
see p. 326). A choice was needed between sequences of the songbird families
which ended either with the nine-primaried songbirds (Wetmore 1951) or with the
crow family (Mayr and Amadon 1951a). Therefore an independent international
committee was appointed at the International Ornithological Congress in Basel
(1954) not to decide on classification but to recommend a standard sequence for
the oscine families (Mayr 1956d). This “Basel sequence” was intended to provide
a standard sequence for communication among ornithologists generally and which
Mayr and Greenway could use for planning the remaining volumes of the Checklist.
The committee voted unanimously for the second alternative, the crows-last
sequence. No claim is made in the report of the committee that the adopted
sequence is the best possible system or even a final one. At the same time, two