NOTES ON THE PHALANGERID MARSUPIAL GENUS
SPILOCUSCUS, WITH DESCRIPTION OF A NEW SPECIES
FROM PAPUA
KRISTOFER M. HELGEN AND TIMOTHY F. FLANNERY
Department of Environmental Biology, School of Earth and Environmental Sciences, University of Adelaide,
Adelaide SA 5005, Australia and
South Australian Museum, North Terrace, Adelaide SA 5000, Australia
A new small-bodied species of spotted cuscus is described from Biak and Supiori, neighboring oceanic islands in
Cenderawasih Bay, northwest New Guinea. The nonvolant mammal fauna of Biak-Supiori is almost entirely
endemic. The geographic origin of another insular species of the genus (Spilocuscus kraemeri) is also discussed:
S. kraemeri is a distinctive species known only from the Admiralty Islands but, due to its putative absence from
the fossil record of those islands, it is thought to have been introduced there from an unknown source population
in prehistoric times. Based on new evidence, we suggest that kraemeri is either native to the Admiralty Islands, or
originally differentiated on the large island of New Britain in the Bismarck Archipelago.
Key words: Admiralty Islands, Biak-Supiori, Bismarck Archipelago, Indonesia, Papua New Guinea, Phalangeridae,
marsupials, Spilocuscus, spotted cuscuses, taxonomy
The spotted cuscuses (the phalangerid genus Spilocuscus
Gray, 1862) comprise a group of colorful, medium sized,
arboreal frugivore-folivores endemic to tropical forests in the
Australo-Papuan region. The distribution of the genus includes
the lowlands of New Guinea, tropical northeastern Australia,
and many Melanesian islands, including several New Guinean
land bridge islands (Yapen, Misool, Salawati, and the Aru
Islands) and several oceanic islands near New Guinea, in-
cluding the Bismarck Archipelago, Waigeo and Batanta, Biak-
Supiori, Numfoor, and the Kai Islands (Flannery 1994). The
range of 1 species of the genus (S. maculatus chrysorrhos) also
extends to the island of Salayer south of Sulawesi (as a result
of human-sponsored introduction?George 1987), and to the
Central Moluccas (Seram, Ambon, Buru, and the Banda
Islands) where it might be either native or introduced (Flannery
1995b; Helgen 2003).
Drawing on their studies of features of the cranium, dentition,
and integument, Flannery et al. (1987) and George (1987) argued
that species of Spilocuscus should be separated generically from
those of Phalanger (sensu stricto, i.e., with content as defined by
Groves [in press]), with which they were previously considered
congeneric (Feiler 1978; Laurie and Hill 1954; Thomas 1888;
Tate 1945). The monophyly of Spilocuscus and its generic-level
separation from other phalangerids has since been supported by
studies using DNA hybridization techniques (Kirsch and Wol-
man 2001; Lapointe and Kirsch 2001) and mtDNA sequence
data (Hamilton and Springer 1999; Osborne and Christidis
2002). Among phalangerid genera, Spilocuscus is characterized
by a strikingly unique combination of traits, including sexual
dichromatism in pelage coloration, ranging from subtle differ-
ences in spotting in S. papuensis of Waigeo to markedly
divergent patterns in S. rufoniger of northern New Guinea and
S. kraemeri of the Admiralty group; pronounced sexual
dimorphism, with females larger than males; a reduced and
internally furred outer ear, rendered relatively inconspicuous in
the pelage; an eye with vertically slit pupils; an enlarged frontal
sinus (the bulging forehead of Spilocuscus skulls); and presence
of a protocone on P3.
Historically, species-level systematics of Spilocuscus have
been highly labile (Feiler 1978; Flannery et al. 1987; Flannery
and Calaby 1987; George 1987; Gray 1862; Laurie and Hill
1954; Schwarz 1934; Tate 1945). Within the last decade,
however, taxonomy within the genus has stabilized. Recent
authors recognize a large-bodied species endemic to the
lowlands of northern New Guinea (S. rufoniger), a smaller,
widespread and variable species ubiquitous in the lowlands
of New Guinea and in tropical northeastern Australia (S.
maculatus, widely sympatric with S. rufoniger in northern New
Guinea), and 2 distinctive insular species, 1 endemic to Waigeo
(and probably Batanta) off northwestern New Guinea (S.
papuensis) and the other endemic to the Admiralty group of the
northwestern Bismarck Archipelago (S. kraemeri?Flannery
* Correspondent: kristofer.helgen@adelaide.edu.au

 2004 American Society of Mammalogists
www.mammalogy.org
825
Journal of Mammalogy, 85(5):825?833, 2004
1994, 1995a, 1995b; Groves, in press). Here we modify this
scheme by describing a 3rd distinctive insular species from
Biak-Supiori in Cenderawasih (? Geelvink) Bay in north-
western New Guinea (Fig. 1).
METHODS AND MATERIALS
Museum specimens discussed here are deposited in the collections
of the Australian Museum, Sydney (abbreviated AM); American
Museum of Natural History, New York (AMNH); Natural History
Museum, London, United Kingdom (BMNH); Museum di Storia
Naturale, Genoa, Italy (MSNG); Museum Zoologicum Bogoriense,
Cibinong, Indonesia (MZB); Nationaal Museum van Natuurlijke
Historie (formerly Rijksmuseum van Natuurlijke Historie), Leiden,
Netherlands (RMNH); Western Australian Museum, Perth (WAM);
and Museum fu?r Naturkunde, Humboldt University, Berlin (ZMB).
Dental terminology follows Luckett (1993). All measurements are
in millimeters. Craniodental variables were measured to the nearest
0.01 mm by the authors with handheld digital calipers.
All handling of animals conformed to guidelines established by the
American Society of Mammalogists Animal Care and Use Committee
(1998).
SYSTEMATICS
Order Diprotodontia Owen, 1866
Family Phalangeridae Thomas, 1888
Genus Spilocuscus Gray, 1862
Spilocuscus wilsoni new species
Holotype.?RMNH 12727, juvenile male, skin, skull (Fig.
2), and postcranial skeleton, from Biak, Cenderawasih (?
Geelvink) Bay (Papua, Indonesia), collected April 1955 by
L.D. Brongersma. This immature specimen is chosen as the
holotype because it has more exact collection information than
the adult paratype.
Paratype.?RMNH 64, adult male, skin and skull (Fig. 3),
??brought by natives from the Schouten Islands?? (?Biak-Supiori,
Papua, Indonesia), collected by T. H. Ruys (date of collection
unrecorded?registered at RMNH on 17 April 1906). An
immature individual living as a family pet on Biak was
photographed but not collected by the 2nd author in September
1992 (Fig. 4), and constitutes an additional paratype.
Diagnosis.?S. wilsoni is a very small-bodied species of
Spilocuscus (condylobasal length about 90 and hindfoot about
55 in the adult paratype) with blue-green eyes (unique in the
genus), a pure white coat in the adult male paratype (shared
only with S. m. maculatus), a reduced inflation of the frontal
sinus (relative to all other congeners), and a spicule-like P2
variably retained in the maxilla (as in all congeners except S. m.
maculatus and S. kraemeri).
Distribution.?S. wilsoni is endemic to the neighboring
oceanic islands of Biak-Supiori in Cenderawasih Bay (Fig. 1).
Interestingly, S. m. maculatus (not S. wilsoni) occurs on
Numfoor (specimens at ZMB), Pulau Num (specimens at
MSNG), and Yapen (specimens at BMNH, ZMB), the other
major islands of Cenderawasih Bay (Fig. 1).
Etymology.?This species is named for Don E. Wilson of the
Division of Mammals at the United States National Museum of
Natural History (Smithsonian Institution), Washington, D.C.,
friend and mentor of the 1st author. We suggest Blue-eyed
spotted cuscus as an appropriate common name.
Description.?S. wilsoni might be the smallest of the spotted
cuscuses. No field measurements are available for adult S.
wilsoni, although the hindfoot of the adult paratype measures
about 55 (without claws) on the dry skin, smaller than any
FIG. 1.?The islands of Cenderawasih (? Geelvink) Bay, Papua,
Indonesia. Spilocuscus wilsoni is endemic to Biak-Supiori. Black bar?
100 km.
FIG. 2.?Cranium and mandible of RMNH 12727, juvenile
holotype of Spilocuscus wilsoni, showing unworn dentition.
826 JOURNAL OF MAMMALOGY Vol. 85, No. 5
Spilocuscus except S. kraemeri (cf. Flannery 1994). S. wilsoni
is similar in size only to S. kraemeri of the Admiralty Islands,
from which it differs in pelage coloration (see below), eye
color, its relatively less pronounced frontal swelling, and
variable possession of P2. S. wilsoni most closely resembles
S. maculatus maculatus in adult coat color and general
craniodental features (e.g., in having high molar crests, finely
crenulate molars, a well-developed buccal kink in the cristid
obliqua of the lower molars, contact between the nasal and
lacrimal on the anterior cranium, and a well-excavated anterior
orbit), but the two differ in size (Table 1), eye color, immature
pelage coloration (cf. Fig. 4; Flannery and Calaby 1987), and in
possession of P2 (generally absent in S. m. maculatus).
The adult paratype (Fig. 3) is a very old individual, with all
molars, upper canines, left I2 and both upper 3rd incisors
excessively worn. Right I2 is missing and the underlying
portion of the premaxilla is completely worn through, and right
i1 is fractured at about one-third to one-half of its height to
apex. There is no sign of the upper 1st incisors. P2 is absent,
although this absence possibly results from heavy wear, as all
teeth (and often the underlying bone of the maxillae and
premaxillae) are heavily worn (for example, only 1 mandibular
unicuspid remains on each side of the jaw; Fig. 3). The occiput
appears to have been sawn off dorsally at the posterior base of
the sagittal crest, abbreviating the basicranium at the posterior
edge of the basioccipital just anterior to the foramen magnum.
Despite the very old age of the paratype, and the tendency for
the cranium of phalangerids to grow throughout life (Menzies
and Pernetta 1986), the skull is small compared to all
S. maculatus (e.g., Table 1). The shape of the skull agrees
closely with S. m. maculatus, although the fronto-parietal
inflation (often grotesquely expanded in adult males of other
Spilocuscus taxa that approach this specimen in age) is
remarkably unpronounced. The sagittal crest is well developed
and the canines (although worn) are relatively large. The
lacrimal and nasal contact one another to separate the frontal
and maxilla (though the resulting border is precariously
narrow). The toothrow is large relative to other elements of
the skull in S. wilsoni (e.g., Table 1; Fig. 5).
The young male holotype is very small compared to
specimens of S. m. maculatus of similar age. Selected
measurements of the holotype followed by the range of
variation in 3 specimens of S. m. maculatus of roughly
equivalent dental development (AM M14597, AM M21857,
AM M21858) include the following: condylobasal length 62.2
mm (versus 73.0?83.4 mm), zygomatic width 39.0 (versus
46.0?49.9), interorbital constriction 10.1 (versus 12.7?13.5),
and nasal length 21.3 (versus 25.4?31.1). Nearly all cranial
sutures (including the basioccipital-basisphenoid suture) are
well-evident in the holotype. In all quadrants of the jaw the 1st
and 2nd molars are fully erupted, the 3rd molars are unerupted,
FIG. 3.?Cranium (lateral, dorsal, and ventral views) and mandible
(lateral and dorsal views) of specimen RMNH 64, paratype of
Spilocuscus wilsoni, adult male from Biak-Supiori (Papua, Indonesia).
!
October 2004 827HELGEN AND FLANNERY?INSULAR SPOTTED CUSCUSES (SPILOCUSCUS)
and there is no sign of the 4th molars. The position of the left I1
is occupied by 2 separate incisors each about half the size of the
right I1 (presumably a congenital abnormality). P2 is present,
and the nasal shares a fairly extensive border with the lacrimal.
S. wilsoni is the only species of Spilocuscus with blue-green
eyes (Fig. 4). All other congeners have a brown or hazel iris
(Flannery 1994, 1995a, 1995b; Gray 1862), although Jentink
(1885) reported a carmine-red iris in S. papuensis (1 specimen
of S. papuensis that we examined [Farid, unpublished
photograph] had a light reddish-brown iris). Phalanger ornatus
matabiru, a recently described phalanger from the islands of
Ternate and Tidore in the North Moluccas, also has blue eyes
(Flannery and Boeadi 1995).
The adult male coat is pure white dorsally and ventrally (at
least in 1 individual?the adult paratype), as in some
individuals of S. m. maculatus of northern New Guinea
(Flannery 1994); the adult female coat is unknown. The
distinctive juvenile coat is creamy buff with brown and gray-
FIG. 4.?Immature Spilocuscus wilsoni on Biak, September 1992. Photograph by T. F. Flannery.
828 JOURNAL OF MAMMALOGY Vol. 85, No. 5
brown mottling on the back and limbs, suffused everywhere
with silvery-buff hairs. The face and upper neck are light
brown (with a slightly lighter crown), the cheeks and venter are
pure creamy buff without mottling, the tail is lighter colored
than the back with less pronounced mottling, and a white flash
is present behind the ear. The nose is pink and the dorsal
surfaces of the manus are a darker shade of brown than the
mottling on the limbs. Both the immature holotype and the
immature individual photographed on Biak (Fig. 4) agree in
this color pattern, which is potentially diagnostic for S. wilsoni
(cf. Flannery 1994; Flannery and Calaby 1987).
DISCUSSION
Comments on Spilocuscus wilsoni.?Jentink (1907) pointed
out the small size of the specimen here designated as the
paratype of S. wilsoni, and was apparently the only author to
discuss Spilocuscus from the Schouten Islands before Flannery
(1995b) noted that a spotted cuscus kept as a family pet on
Biak ??may represent a distinct taxon?? (Fig. 4). Tate (1945) and
Laurie and Hill (1954) previously included Biak in the range of
S. maculatus, presumably based on Jentink?s (1907) comments.
Given its pelage coloration, general craniodental conforma-
tion, and geographic range, there can be little doubt that S.
wilsoni is most closely related to S. maculatus of northern New
Guinea (and other Cenderawasih Bay islands). However, the 2
differ markedly in size, and certain traits observed in specimens
of S. wilsoni (such as a blue-green iris and a variably present
P2) do not apparently occur in S. maculatus (as reviewed by
Flannery and Calaby 1987). Both other Spilocuscus taxa
described from Melanesian islands (S. papuensis from Waigeo
and S. kraemeri from the Admiralty group) are currently
accorded full species status (Flannery 1995b; Groves 2004);
because of its unique combination of morphological traits, we
suggest that species status is most appropriate for S. wilsoni as
well. However, the 4 subspecies of S. maculatus from mainland
New Guinea and Australia (S. m. maculatus, S. m. chrysorrhos,
S. m. goldiei, and S. m. nudicaudatus?Flannery 1994) are
nearly as distinctive as each of these insular taxa, suggesting
that all 7 maculatus-like taxa should probably possess equal
taxonomic rank. All of these taxa are allopatric or parapatric
and characterized by diagnostic combinations of external and
craniodental traits (see Feiler 1978; Flannery 1994; Flannery
and Calaby 1987), but there is evidence that interbreeding is
possible between some forms (Singadan 1996). This suggests
that each of these taxa may be best recognized as allospecies
(sensu Mayr and Diamond 2001) of a superspecies S.
[maculatus]. Nevertheless, pending a formal taxonomic re-
vision of this complex (and elucidation and study of contact
zones between the various taxa on mainland New Guinea), we
refrain from making any formal changes to the current
taxonomic boundaries of S. maculatus (i.e., as defined by
Flannery 1994; Groves, in press).
Biak is more densely populated than any other offshore West
Papuan island (Wikramanayake et al. 2002) and extensive
logging has apparently destroyed considerable forest cover on
the island in recent decades (Petocz 1989; Stattersfield et al.
1998), although the mountainous forests of Supiori are less
disturbed. The 2nd author did not encounter S. wilsoni in the
wild during 2 weeks of intensive mammal survey work on
Supiori in 1992, nor is it present among important series of
nonvolant mammals collected by P. Temple and N. Dixon
FIG. 5.?Selected bivariate plot of Spilocuscus m. maculatus (m) and S. wilsoni (w). (All specimens are adult males, and measurements
are in mm.)
October 2004 829HELGEN AND FLANNERY?INSULAR SPOTTED CUSCUSES (SPILOCUSCUS)
o 
o 
o 
*?> 
i- 
o 
Q. 
a. 
c 
(D 44      46      48      50      52      54      56      58      60      62 
Width of occiput behind external auditory meatus (mm) 
during survey work on Biak in 1962 (specimens at AM and
AMNH) or among collections amassed by the NAMRU-2
expeditions to Biak and Owi in 1976 (specimens at AMNH,
MZB, and WAM?Bergmans and Sarbini 1985). Its apparent
rarity is notable, as certain congeners (S. maculatus and S.
kraemeri) are relatively common throughout their range, even
in disturbed habitats or areas of relatively high hunting pressure
(Flannery 1994, 1995b). However, the largest species of
the genus, Spilocuscus rufoniger, is nearly extinct due to
expanding human population pressure and concerted hunting
throughout its range (Flannery 1995a).
Given its very restricted range and seeming rarity, we
recommend an IUCN ranking of Critically Endangered for this
new species. Additional fieldwork is needed to investigate the
conservation status and general biology of S. wilsoni and other
poorly known endemic vertebrates from Biak-Supiori (see
below).
Mammalian endemism in the Biak-Supiori fauna.?Biak and
Supiori are oceanic islands, and all native elements in the fauna
show signs of having arrived overwater, either by flying (in the
case of birds and bats?Mayr and de Schauensee 1939) or via
sweepstakes dispersal (in the case of nonvolant mammals).
Many species and subspecies of birds are endemic (or near-
endemic) to Biak-Supiori (Aplin 1998; Beehler et al. 1986:24;
Mayr and de Schauensee 1939; Stattersfield et al. 1998), as are
several species of fruit bats, including Dobsonia emersa (a near
endemic species shared only with the adjacent oceanic island of
Numfoor?Flannery 1995b) and an undescribed, endemic
species of Pteropus allied to P. pohlei.
The nonvolant mammal fauna of Biak-Supiori is almost
entirely unique taxonomically. Four marsupial species occur on
these islands (the bandicoot Echymipera kalubu, the glider
Petaurus breviceps, and the cuscuses Phalanger orientalis and
Spilocuscus wilsoni); of these, 1 is an endemic species
(Spilocuscus wilsoni) and 2 are represented by distinctive
endemic subspecies (E. kalubu philipi?Troughton 1945; P.
breviceps biacensis?Ulmer 1940). The remaining species,
Phalanger orientalis, is not taxonomically distinctive and
might have arrived relatively recently to the island as a human-
sponsored introduction (Flannery 1994, 1995b). Several
marsupial lineages that are common and widespread on
mainland New Guinea (such as macropodids, dasyurids, and
pseudocheirids) are poor overwater dispersers (Flannery
1995b) and are absent from the Biak-Supiori fauna.
Five native murid rodents occur on Biak-Supiori (including
the adjacent small island of Owi): Uromys boeadii and Uromys
emmae (each an endemic species known by a single museum
specimen?Groves and Flannery 1994); Rattus jobiensis (a
near-endemic species shared only with the adjacent land-bridge
island of Yapen); the widespread Australo-Papuan species
Hydromys chrysogaster (represented by specimens at AM and
AMNH); and an undescribed Paramelomys allied to P.
platyops (Flannery 1995b; Menzies 1996b). The introduced
commensal rats Rattus exulans and R. rattus are also present on
Biak-Supiori, and Owi (Taylor et al. 1982?specimens at AM,
AMNH, RMNH, WAM).
In addition to many endemic birds and mammals, Biak-
Supiori supports at least 1 endemic frog, Oreophryne kapisa
(see Gu?nther 2003). Given this remarkable range-restricted
vertebrate endemism, the forests of Biak-Supiori must
necessarily be considered 1 of the most important conservation
priorities in Papua.
On the geographic origin of Spilocuscus kraemeri.?Two
species of Spilocuscus occur in the Bismarck Archipelago of
eastern Papua New Guinea: S. maculatus maculatus, which
occurs on the islands of Mussau (in the St. Matthias group) and
New Ireland; and S. kraemeri of the Admiralty group (see
Flannery [1995b] for vouchered insular records). S. m.
maculatus was apparently introduced to Mussau in recent
millennia (Flannery 1995b:106) and to New Ireland in 1929
(Flannery and White 1991), and these populations are mor-
phologically indistinguishable from those of mainland New
Guinean S. m. maculatus. In contrast, the unique features of S.
kraemeri (which include an immediately diagnostic pelage
coloration pattern and small body size) have been appreciated
since its description by Schwarz (1910), although its taxonomic
affinities and geographic origin have never been clear. Tate
(1945) allied kraemeri with Spilocuscus rufoniger, Laurie and
Hill (1954) and George (1987) treated it as a subspecies of
Spilocuscus maculatus, and Flannery and Calaby (1987)
considered its status uncertain. After examining extensive
museum material of S. kraemeri and collecting new specimens
TABLE 1.?Selected craniodental and mandibular measurements for
adult males of Spilocuscus m. maculatus and Spilocuscus wilsoni from
northwest New Guinea. (Immature male specimen of S. wilsoni
included for molar measurements.)
S. m. maculatus S. wilsoni
Condylobasal
length
Mean (SD) 104.5 (5.01) about 90
n 9 1
Range 97.6
108.8
Zygomatic
width
Mean (SD) 70.6 (2.97) 65.9
n 10 1
Range 68.0
76.5
Length of P4 to M4 Mean (SD) 32.8 (1.64) 31.3
n 8 1
Range 29.5
34.4
Nasal length Mean (SD) 41.0 (3.05) 33.4
n 10 1
Range 37.6
46.4
Width of frontal
swelling
Mean (SD) 25.7 (2.97) 18.4
n 7 1
Range 21.7
30.7
Length of M1 Mean (SD) 7.4 (0.35) 6.2
n 10 2
Range 6.7
7.8 5.4
7.1
Width of M1 Mean (SD) 6.2 (0.43) 6.3
n 10 2
Range 5.6
7.0 6.0
6.5
Length of incisive
foramina
Mean (SD) 7.8 (0.58) 6.4
n 7 1
Range 6.9
8.8
Coronoid height
of mandible
Mean (SD) 41.8 (2.13) 35.7
n 8 1
Range 38.2
44.6
830 JOURNAL OF MAMMALOGY Vol. 85, No. 5
from Manus, Flannery (1994, 1995b) argued that S. kraemeri
should be recognized as a distinctive insular species. However,
citing preliminary archaeological evidence suggesting that it
was absent from the fossil record of Manus prior to ??the last
one to two thousand years,?? Flannery (1995b) posited that S.
kraemeri must have been transplanted to the Admiralty group
from an as yet far undiscovered source population. (Human
history in Manus is thought to extend to about 13,000 years
before the present (BP), if not earlier [Kirch 2000].)
Recent archaeological research refutes this claim. At
Pamwak, a rockshelter site in southern Manus, ??C14 dates
taken from charcoal, shell, and Celtis seeds range back to
12,000 BP (14,000 BP calibrated)?? (Williams 1999:242), and
S. kraemeri is represented erratically in the record at least as far
back as about 11,000 years ago. This ancient and spotty
occurrence in the subfossil record suggests to us that S.
kraemeri might be a natural element in the Manus fauna.
(Likewise, the bandicoot Echymipera kalubu is common at all
levels throughout the Pamwak deposit back to about 12,400
years ago; it too could be native to Manus?contra Flannery
1995b:68?and its taxonomic status deserves study.)
Alternately, S. kraemeri might have originally evolved on
the large Bismarck island of New Britain, where (surprisingly)
it might occur today. On zoogeographic grounds Tate (1945)
suspected that a species of Spilocuscus might inhabit New
Britain, but until recently there were no published records of
any species of the genus from the island. In a report describ-
ing recent mammal survey work on New Britain, Anthony
(2001:38) discussed a specimen of ??Spilocuscus maculatus??
purchased in a New Britain market and supposedly hunted on
the tiny island of Bali off New Britain; the photograph of the
skin of this animal clearly reveals that this is S. kraemeri, not S.
maculatus. According to its label, another museum specimen of
S. kraemeri (AM M5117, immature male, skin and skull, with
meager accompanying collection details, registered 10 April
1931) was also collected on ??New Britain.?? If S. kraemeri
actually occurs on New Britain it must be rare there (in contrast
to Manus, where it is common), as very few specimens have
come to light. This potential difference in abundance between
S. kraemeri on Manus compared to New Britain might have an
ecological explanation: another phalangerid, Phalanger ori-
entalis breviceps, is common on New Britain but absent on
Manus (Flannery 1995b); competitive interactions with this
species could potentially explain the relative rarity of S.
kraemeri on the former island. Judging from museum series
and field observations, species of Spilocuscus are generally
rarer than P. orientalis on islands where both species occur,
including the Indonesian islands of Biak-Supiori, Seram,
Ambon, Buru, and Batanta, although the reverse might be the
case on Waigeo, because European museums hold several large
series of S. papuensis but very few specimens of P. orientalis
from that island (see George 1987).
S. kraemeri is commonly sold as a living animal in coastal
markets on Manus (Flannery 1995b; Menzies 1996a), and both
New Britain records could represent translocated individuals or
populations that ultimately originated from Manus. Alternately,
the Admiralty population could have originally differentiated
on New Britain before being introduced to the Admiralties in
prehistoric times, or S. kraemeri could be a widespread
Bismarck endemic that occurs naturally both on New Britain
and throughout the Admiralties. Recourse to the subfossil
record of New Britain and further study of fossil and
archaeological deposits in the Admiralty group will offer
a means of discriminating between these scenarios. A New
Britain origin for S. kraemeri is most attractive in some aspects;
for example, like Biak-Supiori and Waigeo-Batanta (the other
islands with endemic Spilocuscus species), New Britain is
a very near oceanic island, assumably much more easily
reached by sweepstakes dispersal (e.g., chance rafting in
a hollow log) than Manus.
In any case, the origin of S. kraemeri is now less enigmatic:
it has not been translocated from a ??founder population from
further west that remains undiscovered?? (Flannery 1995b);
rather it is probably a true Bismarck endemic, native to the
Admiralty group, New Britain, or both. If Admiralty
populations of S. kraemeri were established naturally by
sweepstakes dispersal, then isolated populations from various
outlying Admiralty island groups (e.g., the Hermits, Exche-
quiers, and Wuvulu) deserve additional systematic attention.
ACKNOWLEDGMENTS
For access to museum specimens and other assistance, we thank C.
Smeenk (RMNH), S. Ingleby and T. Ennis (AM), P. Jenkins, R.
Harbord, and D. Hills (BMNH), D. Lunde and R. Voss (AMNH), P.
Giere and I. Thomas (ZMB), G. Doria (MSNG), I. Maryanto (MZB),
and N. Cooper and R. O?Shea (WAM). We additionally thank C. and
N. Smeenk for many kindnesses during our visits to Leiden, L.
Johnston for producing the map, and S. Richards, Farid, K. Aplin, S.
Donnellan, and D. Wilson for helpful discussion and other assistance.
The first author thanks C. Yuan, A. Chien, and C. Trapani for
hospitality during travels to American and European museums. The
first author is supported by fellowships from the U.S. National Science
Foundation, the Australian-American Fulbright Commission, and the
University of Adelaide. Our research in American and European
museums was supported by grants from the South Australian Museum
and the Smithsonian Institution (to KMH) and the Winifred Violet
Scott Foundation (to TFF).
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Submitted 24 September 2003. Accepted 7 December 2003.
Associate Editor was Eric A. Rickart.
October 2004 833HELGEN AND FLANNERY?INSULAR SPOTTED CUSCUSES (SPILOCUSCUS)