Ornithology, Evolution, and Philosophy 123

Classification 327
ticular families or groups of genera by various ornithologists of this institution
(Amadon, Chapin, Delacour, Mayr, Vaurie, Zimmer). Mayr prepared a number
of influential papers on swallows (1943f, with Bond), shrikes (1943d), and ducks
(1945e, with Delacour). In these macrotaxonomic studies, Mayr took into consideration
many details of the birds’ ecology, habits, and behavior such as nesting and
courtship. With respect to the swallows Sheldon and Winkler (1993: 807) concluded
the discussion of their recent biochemical analysis stating “The groups of genera
outlined by Mayr and Bond (1943) based on nesting habits and plumage patterns
conform to our clades to a remarkable degree.” Mayr outlined the text of the paper
on Anatidae (Delacour and Mayr 1945e, 1946j) and wrote the more general discussions,
whereas Delacour supplied most of the factual detail. They had both agreed
that it was unnatural to separate the mergansers (Mergus) from the goldeneyes
(Bucephala), to lump the pochards (Netta) with the sea ducks, etc. It was one of
the first papers in English-language ornithology (after the comprehensive work
of O. Heinroth and K. Lorenz in German) in which life history data were extensively
used for reclassification. Both authors believed in large genera, since it is
the function of the generic name to express relationship, not distinctness which is
expressed by the species name. The broadening of the (polytypic) species necessitated
a corresponding adjustment of genus limits. Compared with Peters’ Check-list
(vol. 1, 1931), Delacour and Mayr (1945e) recognized 40 genera in the Anatidae
(instead of 62) of which only 22 (instead of 42) were monotypic. They consistently
indicated superspecies in the species list. Their macrotaxonomic conclusions were
in nearly complete agreement with those reached by K. Lorenz (1941) based on
comparative ethological studies of freshwater ducks (Delacour and Mayr were able
to comment on this paper in their supplement, 1946j, after receipt of a copy of
Lorenz’s article which had appeared during World War II). Many publications of
later authors have substantiated this early discovery that highly conservative behavior
patterns contain historical evolutionary (phylogenetic) information at the
level of genera and subfamilies.
The article on the “Classification of Recent Birds” (Mayr and Amadon 1951a)
summarized all this work, which gave considerable attention to the Old World
families, especially Australasian groups, and separated many of them as distinct
families, subfamilies and tribes (Monarchini, Rhipidurini, Pachycephalini, Cinclosomatini;
Subfamily Malurinae; family Grallinidae). This was the first classification
to emphasize the large and independent radiation of songbirds (Oscines) in the
Australasian region comparable to the large radiations of the suboscines in South
America and of the nine-primaried oscines in the New World. The authors determined
the total number of all bird species as 8,590 compared with 8,616 species
listed by Mayr in 1946(a); in later years Mayr’s estimate was somewhat higher (9,000
or even near 10,000 species), because it became increasingly clear that a portion
of geographical isolates previously interpreted as subspecies of polytypic species
possibly have, in fact, reached species status. Mayr and Amadon (1951a) exposed
“the abysmal ignorance of the relationships of most songbird families.” They stated
that habits like, e.g., nest-building behavior are often a better clue to relationship
in birds at the level of species and genera than structure.