3 The New York Years (1931–1953)

40 2 The Budding Scientist
Fig.2.1. Ernst Mayr and Erwin Stresemann at the XIVth International Ornithological
Congress in Oxford, July 1966 (phot. E. Hosking; reproduced from the Proceedings of
the XIVth IOC)
forged links, directly and indirectly, between ornithology and genetics, functional
anatomy, physiology, ecology, and ethology, when he published his seminal volume
Aves (1927–1934) in W. Kükenthal’s Handbook of Zoology. These accomplishments
were of greater general importance and had broader consequences than his ideas
on species, speciation and biogeography. He also supervised a large number of PhD
students including Ernst Mayr as one of the first. He organized biweekly meetings
of the DOG in Berlin, edited the Journal für Ornithologie and the Ornithologische
Monatsberichte which, during the 1930s, were the best among ornithological
journals in the world, and he has been President of the VIIIth International Ornithological
Congress in Oxford in 1934 (Haffer 2000, 2001a,b; Haffer et al. 2000;
Bock 2004a).
The problems of the theoretical species concept and the difficulties of the delimitation
of species taxa in birds as well as the questions of speciation were at the
center of Stresemann’s studies. As one of the first zoologists to do so, he discussed,
around 1920, the biospecies concept based on genetic-reproductive isolation betweengroupsofpopulations.Suchisolationcanonlydevelopinrelativelysmalland
geographically separated populations, he said. He described numerous species and
subspecies of birds from his own collections made in the islands of the Moluccas
and from the material of other expeditions that he received for study: from Balkan
Peninsula, northern Iran, New Guinea, China, Sikkim, and Burma (Myanmar).
His monograph on the birds of Celebes or Sulawesi (1939) was largely responsible
for the new ecological approach to the old science of zoogeography. During the
1920s and 1930s he cooperated closely with his friends Ernst Hartert (1859–1933)
in Tring, England and Leonard Sanford (1868–1950) in New York and New Haven.