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

904 M. Heads
Figure 25 The two related species Astrapia nigra and A. rothschildi.
Figure 26 The black, blue-eyed Parotia species, and P. carolae.
Figure 27 Paradisaea subgen. Paradisaea. The three species with
`decomposed' ¯ank plumes ± P. rubra, P. guilielmi and P. decora.
The ®rst two are a related pair with green forecrown and reddishbrown
iris.
share a longer tail and behavioural similarities (E. Scholes,
pers. comm., September 2000).
Likewise, in their cladogram Frith & Beehler (1998) have
Paradisaea rubra Daudin, of Waigeo and Batanta Islands
(ophiolite terrane) just off the Vogelkop, as the sister species
of P. guilielmi Cabanis, of the Huon Peninsula mountains
(Fig. 27). Neither Frith & Beehler (1998) nor Gilliard (1969)
give any characters linking these two but they do seem
related: in the males of both, but in no other species, the oilgreen
throat colouration extends above the eye to cover the
front of the crown, and the eye is reddish-brown, not yellow.
In addition the tail wires (central rectrices) are longer
relative to body size in these two species. Finally, P. rubra
and P. guilielmi have the outermost primaries with no
emargination on the inner vane, unlike the other species.
Whatever rank this grouping warrants, the biogeographical
af®nity is of great interest and could be investigated further.
Frith & Beehler's (1998) only comment is that the two
species are each an `aberrant sister form' of the main
Paradisaea clade. This interpretation ®ts with the theory
postulating colonization of the offshore islands and coastal
ranges from the central ranges, but it is not consistent with
the cladogram, in which P. rubra and P. guilielmi together
form the sister group to the rest of Paradisaea subgen.
Paradisaea. The invasion theory would predict the two
outlying species to be separately related to the central group
of species, as implied in Frith & Beehler's comments. The
mutual af®nity of the two species is inexplicable under the
dispersal theory, but is easily compatible with an accreted
terrane model of New Guinea biogeography (Heads, 1999),
or indeed any model that accepts geological change, such as
strike-slip movement, as relevant to biological distribution.
In a similar example, Melipotes (Meliphagidae) comprises
three species: the black-breasted M. gymnops Sclater (Arfak,
Tamrau and Wandammen Mountains) and M. ater Roths
child & Hartert (Huon Peninsula mountains), separated by
M. fumigatus Meyer with a slaty lower breast (Rand &
Gilliard, 1967). Melipotes' putative sister group is another
frugivore, Macgregoria De Vis (Cracraft & Feinstein, 2000)
(formerly considered a bird of paradise), which itself shows a
disjunction between the Star Mountains and the Papuan
Peninsula.
Other Vogelkop disjunctions involve taxa known only
from there and western PNG, especially the Karius Range ±
Muller Range area. Examples in the birds of paradise are the
black, blue-eyed Parotia species (with the gap ®lled by
P. carolae Meyer) (Fig. 26), and the long-tailed Astrapia
species (with the gap ®lled by A. splendidissima Rothschild)
(Fig. 28). Drepanornis albertisi cervinicauda Sclater has a
very similar disjunction: Weyland Mountains ± Doma Peaks.
Frith & Beehler (1998) downplay these Vogelkop disjunctions
± in the Astrapia species the `curious' plumage
similarities may represent symplesiomorphies (no evidence
is given), the disjunction in Paradisaea is hardly mentioned,
in the black parotias the disjunct forms are `certainly' sister
taxa but the mode of their differentiation is `unclear', and
in Drepanornis the distribution is `peculiar in the extreme'
and may be a taxonomic `artefact'. Nevertheless, the
Vogelkop ± Huon Peninsula disjunction and related patterns
occur in many other animals and plants and are
probably important clues to the history of northern New
Guinea and their biota.
The Vogelkop ± Huon disjunction is seen in invertebrates
such as the spiders Argiope aemula (Walckenaer) and
A. appensa (Walckenaer) (Levi, 1983) and in plants such
as the following:
Hartleya Sleum. (Vogelkop, disjunct south of Lae at
Mounts Shungol and Kaindi) (Sleumer, 1971),
Ó Blackwell Science Ltd 2001, Journal of Biogeography, 28, 893±925