3 The New York Years (1931–1953)

148 4 Ornithologist and Zoogeographer
since 1940, most have been described from specimens collected earlier, only 23
from newly discovered populations (Mayr and Diamond 2001g: 34).
Studies of the Whitney Collections
In January 1931, Ernst Mayr plunged into his work on the Whitney collections
which had arrived in New York since 1921 but not studied in detail (including his
own collections from the Solomon Islands). He had about ten papers published or
inpressbytheendofthatyear.
“I work here really like a madman. The revisions of Pachycephala are in press;
currently I study the Polynesian flycatchers. As soon as the revisions of the genera
are finished, I shall prepare books on (1) Polynesia, (2) Solomon Islands and
Bismarck Group and (3) New Guinea” (to W. Meise on 11 April 1932; transl.)
and “I sit on two undescribed genera and many new species, among them an
eagle. I would never have dreamed of something like that; I no longer describe
‘dirty’ subspecies unless for zoogeographical reasons” (to W. Meise, October 1931;
transl.).
Mayr took notes on plumage colors and measured thousands of bird specimens
(wing, tail, bill, tarsus) determining the individual variation of local populations
and the geographical variation of subspecies and species. “He worked as a field
naturalist but to laboratory standards of inference and proof–the essence of border
practice” (Kohler 2002: 265). In some of his articles Mayr treated the avifauna
of particularly interesting islands, in others he revised differentiated genera or
species groups monographically. In the first paper (1931b) which appeared only
two months after he had started to work at the AMNH, he introduced into the
international literature the important concept of “superspecies” as an equivalent
of the term “Artenkreis” coined by Rensch (1928, 1929). Mayr had read Rensch’s
book, The Principle of Polytypic Species and the Problem of Speciation (1929) upon
his return from the Solomon Islands in 1930 and admired it greatly. He defined
superspecies as “a systematic unit containing geographically representative species
that have developed characters too distinct to permit the birds to be regarded as
subspecies of one species” (1931b) explaining:
“I regard superspecies as a convenient compromise between diverse schools
of ornithologists, the extremely modern ones, on one side, who want to put together
as a species all geographical representatives, disregarding the most striking
morphological differences, and the conservatives, on the other side, who demand
perfect intergradation as a criterion” (p. 2).
This paper (1931b) is devoted to a study of the widespread Collared Kingfisher
(Halcyon chloris). Mayr described several new subspecies from the New Hebrides,
Santa Cruz Islands, and Rennell Island noticing the conspicuous differentiation
of peripheral isolates: “The birds of the outposts, especially at the periphery of
distribution, show advanced characters that lead to pronounced differences in
appearance” (p. 1). “The sympatric occurrence of two taxa on the same island
proves that they cannot belong to one species” (p. 3).