Ornithology, Evolution, and Philosophy 123

Zoogeography 177
Table 4.2. Degree of endemism in montane species of Passeres on three New Guinea mountains
(after Mayr 1940c); two percent values under Arfak slightly changed
Arfak Cyclops Saruwaget
Not endemic 36 = 40.4 % 21 = 72.4 % 59 = 68.6 %
Endemic subspecies 46 = 51.7 % 8 = 27.6 % 23 = 26.7 %
Endemicsemispecies 5=5.6% 0=0% 3=3.5%
Endemicfullspecies 2=2.2% 0=0% 1=1.2%
Total species 89 = 100 % 29 = 100 % 86 = 100 %
a button quail) indicated to Mayr (1943h) that this plant formation is older than
human colonization.
Geographical isolation of the faunas inhabiting the three New Guinea mountain
ranges which Mayr explored in 1928–1929 led to the differentiation of the respective
taxa of birds as illustrated in Table 4.2. There are several endemic species and
numerous endemic subspecies. Even most of those species which are listed as
undifferentiated are slightly different on each mountain, only these differences are
below the “taxonomic threshold” of subspecies (Mayr 1940c).
IntheintroductiontohisList of New Guinea Birds Mayr (1941f) explained: “In
1930, on my return from New Guinea, I planned to write an ornithogeography of
the Papuan region. It soon became apparent to me that no such work was possible
without a reliable list of the birds of the New Guinea region and that it would be
my first task to prepare such a list” (p. V). At the annual meeting of the American
Ornithologists’ Union in Pittsburgh (1936) he presented a zoogeographical analysis
entitled “The birds of the New Guinea region,” illustrated with lantern slides, and
in 1969 (e, p. 11) he stated “a more detailed study [of bird speciation in New Guinea]
by Mayr is in preparation,” but the manuscript was never completed. It should be
noted, however, that several aspects of the zoogeography and speciation of New
Guinea birds are treated in Mayr’s book of 1942(e).
Meanwhile, some data on the changing distribution of rainforest and more open
vegetation in the lowlands of New Guinea and the Malay Archipelago during the last
several million years have become known (Hope 1996, Morley 2000). According
to Pratt (1982, Beehler et al. 1986) these changes caused temporary separation
and differentiation (i.e., subspeciation and speciation) of animal populations in
ecological refugia.
Australia
Mayr’s zoogeographic analysis of the Australian avifauna (1944e, 1944k), still valid,
revealed endemic families, genera, species, and subspecies. Most immigrants came
from Asia and the region of the Malay Archipelago across ocean barriers (see also