Birds of paradise, biogeography and ecology in New Guinea: a review

908 M. Heads
Figure 30 The distribution of Paradisaea rudolphi in central
PNG (there are additional records of P. r. rudolphi further SE).
Figure 32 Orchidaceae. Corybas royenii Kores (triangles), Dendrobium
kerewense van Royen (stars), D. guttatum J.J. Smith (squares),
D. semeion van Royen (squares) (the af®nities of this species with
West Irian species are indicated by arrow), D. chamaephytum
Schlechter (continuous line), D. euryanthemum Schlechter (continuous
line), D. kerigomnense van Royen (at K ˆ Mount Kerigomna),
D. auranti¯avum van Royen (dots connected by dotted
line), D. alpinum van Royen (hatched line) and D. teligerum van
Royen (broken line).
Figure 31 The distribution of Loboparadisaea in the PNG Highlands
(L. s. sericea extends further west).
other species have races on the outlying Schrader Range,
north of the craton margin and between the Jimi and Ramu
Rivers, that are distinct from birds in the remainder of the
highlands: Melidectes rufocrissalis Reichenow, M. belfordi
De Vis, and Astrapia stephaniae.
It is interesting that parts of the Schrader terrane strongly
resemble the northern part of the Owen Stanley terrane
geologically (Pigram & Davies, 1987). If the Schrader
terrane should prove to be a dismembered portion of the
Owen Stanley terrane it would imply a left-lateral offset of c.
300 km along the Ramu-Markham and Bundi Fault Zones.
Similar biogeographical breaks at the craton margin occur
in other plant and animal taxa. The shrub Drimys piperita
entity `reducta' (Diels) Vink: Wissel Lakes, Mount Wilhelmina,
Mount Giluwe and the Kubor Mountains, and entity
`subalpina' Vink: Mount Wilhelm, act as a pair of `replacing
taxa' (Vink, 1970). Vink reported the `unexplained circumstance'
that the form of reducta most distinct from subalpina
is found at the Kubor Mountains ± the locality closest to
Mount Wilhelm, while the form which connects the two
morphologically, entity `subpittosporoides' Vink, is restricted
to Mount Wilhelmina. Again, this arrangement could be
explained by (right) lateral movement of terranes.
Other examples of plant differentiation around the craton
boundary include species of orchids (Corybas Salisb.,
Dendrobium Sw., Fig. 32; Glossorhyncha Ridl., Fig. 33),
Rhododendron L. (Fig. 34), Compositae (Tetramolopium
Nees, Fig. 35; Olearia Moench, Fig. 36) and Rubiaceae
(Amaracarpus Blume, Fig. 37) (distributions from van Royen,
1979±1983). Sometimes these angiosperms are assumed to
be recent groups, but recent molecular work has found that
Orchidaceae, for example, may have evolved `much earlier
than is traditionally believed' (Cameron, 2000).
Vertebrates other than birds also show the biogeographical
break at the craton margin clearly. The lizard Emoia p. purari
Brown ranges in PNG east to Karimui, while the second
member of the species, Emoia p. physicae (DumeÂril &
Bibron), replaces it from Wau eastwards (Brown, 1991).
Colubrid snakes (Fig. 38) show a similar distributional break.
In mammals, similar distributions are shown in marsupial
genera (Fig. 39) (Flannery, 1995) and bat species (Figs 40 &
41) (Bonaccorso, 1998).
Flannery (1995) observed that SE New Guinea (south of a
line: Kerema ± Garaina) is biogeographically distinct from
the central PNG highlands and has a `particularly high
Ó Blackwell Science Ltd 2001, Journal of Biogeography, 28, 893±925