Ornithology, Evolution, and Philosophy 123

Birds of Australia, the Malay Archipelago and Southeastern Asia 159
Study of the birds of the Philippines led to several taxonomic reviews, comments,
descriptions of new subspecies, e.g., of the Honey Buzzard (Pernis apivorus, 1939d)
and Tailorbird (Orthotomus, 1947b) and revisions of the classification and nomenclature
of various other taxa (Delacour and Mayr 1945m). These articles were
byproducts of a book, Birds of the Philippines by J. Delacour and E. Mayr (1946k)
published to facilitate the identification of birds in the field. The work associated
withthisprojectwasaboutevenlysharedbybothauthors.Numerousexcellent
line drawings by E.C. Poole and A. Seidel illustrate many species. Keys permit the
determination of species; subspecies are also briefly described. Remarks on ecology
and habits of the birds point to insufficient knowledge and gaps to be filled.
Zoogeographically, most Philippine birds show Malaysian affinities, but some have
closer ties with Oriental and Palearctic elements.
Mayr’s discussion of the “Evolution in the family Dicruridae” (Mayr and Vaurie
1948d) was based on a taxonomic revision of the drongos by Vaurie (1949) and
therefore published in coauthorship. This family is widespread in the Old World
tropics. Several of the 20 species are well differentiated in the Malay Archipelago
(Fig. 4.8). Mayr emphasized here again that the more distinct subspecies and
semispecies are geographically isolated and occur in peripheral parts of the species
range, where they vary rather unpredictably. Those which readily cross water gaps
formed widespread polytypic species and superspecies.
Southeastern Asia
Mr. Arthur S. Vernay, a Trustee of the AMNH, sponsored several zoological expeditions
to northern Burma (Chindwin region) during the period 1932–1936, with
MajorJ.K.Stanfordinchargeofbirdcollecting.E.Mayr,whowasaskedtostudythe
collectionsgiventotheAMNHpublishedtheresultsinThe Ibis of 1938 and 1940–41
(with J.K. Stanford supplying field notes). Several British ornithologists had been
rather unhappy that an inexperienced American colleague who had never done
any work in this region should study this important collection. However, eventually
they admitted that they themselves could not have done a better job.
An interesting example of discontinuous geographic variation of alternative
plumage colors (white, gray, black) is presented by the Black Bulbul (Hypsipetes
madagascariensis). The populations are fairly uniform, where they are isolated
on high mountains (Fig. 4.9). However, hybrid populations develop where
several of these forms come in contact with one another, which occurs from
northeastern Burma into China south of the Yangtze River (Mayr 1941n, 1942e:
83–84).
Mayr’s real triumph of working up the Burma collection provided the colorful
minivets (Pericrocotus) (Fig. 4.10). Two exceedingly similar species were always
confounded under the name P. brevirostris until Mayr (1940e) discovered a sibling
species mixed in with the series of brevirostris. A name (ethologus) was already
available for the newcomer. The two species co-exist over a wide range from Sikkim
eastward. At first Mayr’s finding was doubted by Ticehurst, Whistler, Kinnaer,