Temminck, C.J. (1836): Discours préliminaire destiné à servir d'introduction à la Faune du Japon. Coup-d'oeil sur la faune des iles de la Sonde et de l'empire du Japon. Type locality: Mt. Lamantsjieri, Fakfak Div., Lobo district, near Triton Bay, West Papua, Indonesia (Husson, 1955; Groves, 1982, 2005).
Taxonomy: This is the most primitive member of the short-footed species group compromising eleven species in the Genus Dendrolagus (D. ursinus, D. goodfellowi, D. matschiei, D. dorianus, D. stellarum, D. pulcherrimus, D. mayri, D. notatus, D. spadix, D. mbaiso, D. scottae) which share the derived character states of short feet, yet it is so different from the remaining species in the short-footed group that it merits placement in a subgroup of its own. It is, in several ways, the least specialized member of the group. The description of this species was published by Coenraad Jacob Temminck (the first director of the Rijksmuseum in Leiden) as Hypsiprymnus ursinus in a footnote to a work on the fauna of Japan (Temminck, 1836), and it was the first Dendrolagus to receive a scientific name. The specimens upon which Temminck's description was based were collected in 1828 by the two Dutchmen Dr. Salomon Müller and his companion Heinrich Christian Macklot, who had been sent to the Dutch East Indies in June 1826 by the Natural History Commission for the Netherlands Indies. This commission had been formed, in part at the instigation of Temminck himself, in order to increase scientific knowledge of the Dutch colonial possessions. Müller and Macklot visited the Lobo district on the southwestern coast of New Guinea aboard the Dutch Corvette Triton. In all they obtained four specimens of a small, blackish tree-kangaroo from local hunters which had kept them as pets for some time, three of them were killed and entered the stewing pot but an adult female was kept alive and subsequently brought by Müller and Macklot to Keopang, Timor and later to Ambon where it died, for almost 50 years virtually everything Europeans knew about living tree-kangaroos were learned from their observations of this animal (Flannery et al. 1996).
In 1841, when Schlegel & Müller named the genus Dendrolagus ascribing to it D. ursinus and D. inustus (Schlegel & Müller, 1841). This species is considered to be monotypic (Groves, 1982; Flannery 1990, 1995b; Flannery et a. 1996; Martin, 2005) but the taxonomic history of this species remains debated. It was the first tree-kangaroo to receive a scientific name, but it subsequently been neglected by researchers and as a result very little is still known about it. Some authors have argued that two distinct forms exist, one with reddish-brown cheeks and another with white cheeks.
Rothschild & Dollman (1936) recognized seven species which they assigned to three groups primarily according to the position of the median dorsal hair-whorl, with D. ursinus placed in group 3 along with D. inustus, D. bennettianus and D. lumholtzi. The genus was revised again by Tate (1948) who was unwilling to opine the exact number of valid species but divided the genus into three groups, with this species placed in the D. ursinus group together with D. inustus, D. keiensis and D. finschi. This revision, however, appears to have been based on a few actual specimens of D. inustus, D. dorianus and D. lumholtzi. The other names would seem to have been allocated to one or other of these three "groups" from their original descriptions only. He was, however, prepared to urging very strongly that D. ursinus and D. inustus were actually colour phases of the same species. He listed fourteen characters purporting to distinguish his three species-groups. At best, they characterize the three species of which he actually had specimens at his disposal (D. inustus, D. dorianus and D. lumholtzi), but many of the characters are so variable as to be useless taxonomically (Groves, 1982). Unfortunately the revision by Tate was accepted more readily than that of Rothschild & Dollman due to his authority. Lidicker & Ziegler (1968) were inclined, on Tate's authority, to synonymise D. inustus with D. ursinus. Tate's decision based on little convincing evidence (the same type locality, and his own "unproved suspicion") to align D. ursinus with D. inustus, even to the extent of making them probably synonymous, was more unfortunate. Rothschild and Dollman (1936) had assigned them to the same species-group and it is ironic that this decision, the only one with which Tate concurred, was their only serious error. Husson (1955) listed a whole suite of characters distinguishing them (based on the type series) but his paper was not noted by Lidicker and Ziegler (Groves, 1982). Kirsch & Calaby (1977) listed the species as recognized by Rothschild and Dollman, but without species groups. Gorge & Schurer (1978) provided some notes on the distinguish characters of three species commonly seen in zoos but liable to be misidentified, clearly distinguish D. inustus from D. ursinus.
The white-cheeked form was described as a new species (D. leucogenys) by Matschie (1916b) from Dorei Bay. Husson & Rappard (1958) suggested that leucogenys may be a valid race or even an distinctive species. However, both the red-cheeked and white-cheeked forms occurs at the same localities, as well as a rare form with golden-red cheeks (Groves, 1982). Hence it is likely that these are just colour forms of the the same species. However, it remains obvious that detailed fieldwork as well as further examinations of available museum material is necessary to clarify these matters (Flannery et al. 1996).
Characteristics and identification: This is one of the largest species of Dendrolagus, with males being considerably larger than females. It is a short-footed species, with medium toe-shortened; ear large, furry internally and tufted externally; tail short; one or two whorls, somewhat behind scapula. Interorbital region flat; orbital rims ridged; nasals extremely constricted in the middle; temporal lines remain separate; toothrow straight; maxillary-premaxillary suture runs up and then angles back; a bregma bone usually present; a small, even tiny forearm below postorbital process; inferior lacrimal forearm larger than superior; secator much the same as in D. inustus, but mesial prominence reduced.
It can be distinguished from all other Dendrolagus species by the back which is covered in long black fur and its belly which has a dirty brownish colour. Set off from light pale-coloured face, and the cheeks are either reddish or white, the tail is long and black, and often bears a white tip with a brownish spot at base, and the long-tufted ears are unique in the genus. The underside is short-haired and buffy. The measurements of this species is as follows Head-body: 660mm (male), 530-650mm (female). Tail: 720mm (male), 590-720mm (female). Hindfoot: 110mm (male), 108mm (female). Ear: 36-48mm (female). Skull characters: the forehead is flat, with little or no convexity and depressed in the midline. The superior orbital margins are ridged, and evenly rounded. The nasal bones are strongly constricted between the premaxillae and re-expanded at their tips. A bregmatic ossicle is usual in this species, and the nasal bones showing steeper regression slopes than in most other species of Dendrolagus species (Dollman & Rothschild, 1936; Groves, 1982; Flannery, 1990, 1995b).
Distribution: Endemic to the Papuan region this species has a limited geographic distribution restricted to the Bird's Head (Vogelkop) Peninsula and Bird's Neck region, and it is distributed as far east the mountains fringing the western shores of Etna Bay, Papua Province (Flannery, 1990, 1995b; Flannery et al. 1996; Groves, 1982, 2005). The occurrence of this species on the Bird's Head (Vogelkop) Peninsula remains poorly known, it has been reported as having an extraordinary elevational range ranging from sea-level to at least 2,300m asl. In his revision of the genus Groves (1982) examined a total of 16 specimens from four localities (including the type locality), namely the Arfak Mts, Dorei Bay (= Manokwari) in the north-east as well as Teluk Berau situated on the southern coast of the Bird's Head (Vogelkop) Peninsula.
Following extensive fieldwork, however, Timothy Flannery begun to doubt whether it occurred in the lowlands. There is reports of it from seasonally dry lowland rainforest but this is based upon sightings and old reports from the nineteenth century so may be in error (Flannery et al. 1996). To the best of our knowledge there is still no confirmed records of this species from the Tamrau Mountains, situated to the west of the Arfak Mts, but during a visit to the southern foothills of this mountain range trading skins and tails representing adult individuals of this species was observed (S. Hogberg pers. obs). However, there has been long been a traditional trade in tree-kangaroos and their fur throughout New Guinea, and many have been traded from distant regions (Flannery et al. 1996).
It is probably present on the Fakfak Peninsula (Fakfak and Kumawa Mts) but documented records is currently lacking (Flannery 1990, 1995b; Flannery et al. 1996; Leary in litt 2008). During fieldwork in early 1996 Timothy Flannery located the easternmost distribution boundary of this species, at an elevation of 1,000m asl. in the mountains on the western shores of Etna Bay on the Bird's Neck. Local hunters in the area were unanimous that the species occurred no further east. Thus, the lowlands around the Etna Bay form an effective barrier to it (Flannery et al. 1996).
Natural History: it is now found from ca. 1,000m and up to at least 2,300m (Flannery, 1995b, 1996). Has been reported as having an extraordinary elevation range, from sea-level to high mossy forest, this is based upon a sighting from seasonally dry lowland forest (Husson & Rappard, 1958) but which may be erroneous (Flannery, 1996; see "Conservation Status" for more information). It certainly occurs at middle elevations up to extremely mossy upper montane forests, it occur sympatric with the D. i. inustus in parts of the distribution while in the Arfak Mts this species is restricted to higher altitudes while the Grizzled Tree-kangaroo inhabits the lowlands. Little is known about the diet of this species, in 1828 Müller and Macklot kept a specimen a pet on Timor which generally stayed high in the crowns of trees and almost exclusively feed upon the fruits and leaves of two large figs when the trees were fruiting (Schlegel and Müller, 1845). Van Musschenbroek (1883) also kept a specimen as a pet and noted that it would eat smoked beef and sardines among other food. Husson & Rappard (1958) noted that a captive specimen kept in dry lowland forest seemed to prefer the leaves, twigs and bark of Morus alba trees imported from Java but that it also browsed on the leaves of Antocarpus sp. it never grazed but would eat rice, bread and vegetables. An sub-adult male kept as a pet in the Arfak Mts ate a wide variety of plant food. These old reports suggest that it may eat considerable quantities of fruit, which is clearly unusual as most members in the genus are leaf-eaters (Flannery, 1996). A female with a single short-furred pouch young was collected in early October 1986 in the Arfak Mts, while in April 1992 a half-grown young was captured near the summit of Mount Gripo, Arfak Mts (Flannery, 1990, 1995a).
(The individual acquired by Bronx Zoo in 1914-15)