Ornithology, Evolution, and Philosophy 123

118 3 The New York Years (1931–1953)
taxonomic work on the Whitney Collections from the southwest Pacific, of course,
was immensely facilitated by the Rothschild Collection which provided valuable
comparative material including numerous type specimens.
The new classification of the combined collections permitted a species count
of the birds of the world, based partly on actual numbers, partly on estimates.
The results were 8,500 species (Mayr 1935d) and 8616 species (Mayr 1946a). The
stability of these figures would depend entirely on the future development of the
taxonomic viewpoint (1935d: 23). This turned out to be an amazingly perceptive
prediction, since the application of the concept of allospecies (and superspecies)
during the 1940s and 1950s led subsequently to the upgrading of many
peripheral and well-differentiated “subspecies” to the status of (allo)species so that
without an appreciable increase in the number of newly discovered species, the
present estimate is 9,500 to 10,000 species of the world (a “quiet revolution,” Mayr
1980d).
In the reference 1946(a), Mayr doubted “that in the entire world even as many
as 100 new species remain to be discovered” (p. 67). This turned out to be underestimated.
162 “good” species have been discovered between 1938 and 1990.
Periodically, Mayr reviewed critically the taxa described as new species in the
literature (Zimmer and Mayr 1943b; Mayr 1957a, 1971d; Mayr and Vuilleumier
1983g, 1987c; Vuilleumier et al. 1992m). In 1957, he felt that the bird fauna of the
world was then so well known that probably no more than 20 species would be
discovered during the next 10 years. This estimate was again surpassed. Thirtyfive
good species were described until 1965, a rate of 3.5 species per year. This rate
has only slightly decreased to 2.4 species per year until 1990 (Vuilleumier et al.
1992m). Most of these new species have been overlooked for so long because they
are sibling species or have exceedingly small ranges in regions of difficult access
like, e.g., parts of the tropical Andes Mountains. Recently, Mayr and Gerloff (1994t)
estimated the total of subspecies of birds as 26,206.
Colleagues at the American Museum
“There were (in the 1930s and 1940s) an intellectual excitement and a level of professional
competence and ornithological universality at the American Museum that
had nowhere existed previously and that perhaps can never again be duplicated”
(Mayr 1975c: 372). Chairman of the Bird Department was Frank Michler Chapman
(1864–1945), an outstanding ornithologist with imagination and a broadly
interested researcher (Fig. 3.9), who had published pioneering monographs on
the birds of Colombia, Ecuador, the Peruvian Urubamba Valley and the Roraima
Mountains (Mayr 1975c, 1980n; Lanyon 1995; LeCroy 2005; Vuilleumier 2005a).
He had popularized ornithology in North America, promoted the cause of conservation
and pioneered life history studies of tropical birds but now being in his
seventies was no longer an innovator. Mayr felt that it was not to the best of the
department to wait until Chapman, in 1942, would retire at the age of 78 years.
Robert Cushman Murphy (1887–1973) was employed in 1921 in order to write
a report on the birds collected by the Brewster-Sanford expedition to the coastal