Handbook of the Mammals of the World - Volume 5

3

FAMILY ?????? ??????

FAMILY TACHYGLOSSIDAE Echidnas

The sprawling limb posture of the Eastern Long-beaked Echidna contributes to a distinct rolling gait that is unique among modern mammals. The hindquarters sway and amble during locomotion. The humeri are positioned at roughly right angles to the body as opposed to being held beneath the body as in other mammals. This type of limb positioning is similar to that of reptiles. The limb remains almost horizontal to the substrate during locomotion, forcing it to rotate about its axis rather than move in a front-and-back manner. This gait of the Eastern Long-beaked Echidna is slow and awkward in appearance and suggests limited running capabilities.

Zaglossus bartoni Papua New Guinea.

Photo: Jean-Paul Ferrero/AGEFotostock

than the surrounding area and have hairs that the young hold on to. Before a female lays her egg, a pouch forms as the underlying crescent-shaped mammary glands hypertrophy.

There is very little sexual dimorphism among species of echidnas. In Short-beaked Echidnas, the male-to-female mass ratio is 1·1:1, although in practice, echidna sexual dimorphism is even less obvious because both sexes show a large annual cycle of changes in their body masses. There are not enough data on long-beaked echidnas to detect any differences in body masses within geographical populations, but they seem likely to show a similar slight sexual dimorphism. Outside the breeding season, male echidnas can be distinguished from females by the presence of a spur. This spur is similar to that of Platypuses, but it is not firmly fixed to the ankle, suggesting that it can-

not be used aggressively. Juveniles of both sexes have a spur covered with a sheath. The sheath sloughs off when individuals reach reproductive maturity, leaving a shallow pit in females and an adult spur in males. The spur has a central canal, connected by a duct to a gland in the thigh area (the crural gland).

This gland hypertrophies during the breeding season and produces a milky fluid, but unlike the secretion from the Platypus femoral gland, it does not appear to be toxic.

Habitat The three extant species of long-beaked echidna are now confined to the central mountain ranges spanning the full ­east‑west

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Echidnas have been observed swimming in dammed pools and across streams. This activity is mostly likely a strategy to cool during periods of extreme heat.

Echidnas are susceptible to heat stress and body temperatures above 34°C are most likely lethal; they do not pant and lack sweat glands.

This Short-beaked Echidna is using its snout as a snorkel while swimming. On Kangaroo Island, Short-beaked Echidnas were observed swimming short distances from shore out into the ocean and back without any noticeable disturbances or pressure from predators. Other strategies to avoid heat include taking refuge in cool microenvironments, like abandoned rabbit burrows, rock caves, and hollow logs.

Tachyglossus aculeatus near Mount Molloy, NE Queensland, Australia.

Photo: Hans & Judy Beste/ Lochman Transparencies

FAMILY TACHYGLOSSIDAE Echidnas

These Short-beaked Echidnas illustrate common defense tactics.

A large muscle, the panniculus carnosus, is located just beneath the skin of the echidna. The muscle covers the sides and the dorsal surface of the body, but it is thicker on the dorsum. By contracting the muscle in selected regions of the body, the echidna can take on a variety of shapes that allow it to present its attacker with spines while protecting its soft underbelly.

This tactic proves useful in areas where hard substrates prohibit digging below the surface for protection. Echidnas have also been observed to discharge a strong stream of pungent urine toward a perceived threat. In the rear leg, the tibia and fibula of echidnas are rotated so that the hindfeet are pointed to the rear. The second, and sometimes third, digit on the hindfoot is long and recurved.

These are referred to as grooming claws and are used to comb through the spines to remove dirt, insects, and leaf litter.

Above: Tachyglossus aculeatus acanthion South of Carnarvon, Western Australia, Australia.

Photo: G端nter Ziesler

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Below: Tachyglossus aculeatus setosus Cape Range National Park, Western Australia, Australia.

Photo: Steven David Miller/ AGE-Fotostock

FAMILY ORNITHORHYNCHIDAE Platypus

Burrows of Platypuses are commonly established in soil banks of riparian habitat. Entrances are placed near the typical water level and are often difficult to see due to overhanging vegetation.

Burrows provide resting and nesting sites, protection from predators, and relief from extreme winter and summer temperatures.

Platypuses display a predominately nocturnal activity pattern, emerging from their burrows in late afternoon, foraging for ten to twelve hours along a water system, and returning in early morning.

Foraging efforts include swimming on the surface and multiple short dives to search for food on the substrate.

Ornithorhynchus anatinus Tasmania.

Photo: Dave Watts/Lochman Transparencies

Information regarding the food consumed by the Platypus has been reported since the early 1800s from investigation of the contents of its cheek pouches. The Platypus appears to be predominantly a dietary opportunist, exploiting temporal and spatial availability of prey items, especially insect larvae and nymphs. Caddisflies (Trichoptera), mayflies (Ephemeroptera), dragonflies (Odonata), and stoneflies (Plecoptera) are the dominant insect groups consumed, but adults of free-swimming species, such as shrimp, crayfish, water beetles (Coleoptera), aquatic bugs (Hemiptera), and occasionally tadpoles, small fish, water snails, small clams, and worms, are also consumed. Soft-bodied animals, including worms and dipteran larvae, may not persist in the cheek pouches for extended periods and their contribution to the diet may be underestimated.

Breeding

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The reproductive organs of male and female Platypuses begin to increase in size during winter and reach their maximum in

spring when mating normally occurs and males become more aggressive. Copulation has been observed a number of times in captive individuals held in various Australian zoos, but very seldom in wild individuals. Male Platypuses initiate most mating interactions, but the compliance of the female appears to determine if mating behavior culminates in copulation. Precopulatory behavior includes a range of courtship activities that last from less than a minute to one-half an hour or more, usually occurring over several days. These behaviors include the male and female grasping each other and rolling sideways several times, diving, touching, and swimming past each other.

Often such interactions are broken off and not recommenced.

The male Platypus frequently grasps the tip of the tail of the female, after which the pair swims in tight circles. During a typical copulation, the male grasps the female by the tail from behind with his bill. He then wraps his tail under the female’s body to one side of her tail and moves forward, nuzzling and gripping the fur on the shoulder or neck with his bill. With their bodies in this position, the male everts his penis through the cloacal opening and inserts it, via the cloaca of the female,

The hindfeet of the Platypus are partially webbed, have sharper claws than the forefeet, and are used for grooming and traction during burrow excavation. A venomous spur of about 1·5 cm in length is located on the ankle region of both hindlimbs in males.

The hollow spurs receive venom through a duct leading out of a venom gland located in the upper region of each hindlimb.

Males most likely use spurs during intraspecific fighting or for defense. In humans, the venom causes pain (in some cases severe), inflammation, and tenderness at the injection site.

Ornithorhynchus anatinus LOCATION PENDING Photo: D. Parer & E. Parer-Cook/ Minden Pictures/FLPA

FAMILY ORNITHORHYNCHIDAE Platypus

Above: Ornithorhynchus anatinus LOCATION PENDING Photo: D. Parer & E. Parer-Cook/ Minden Pictures/ASA Below: Ornithorhynchus anatinus Victoria, Australia.

Photo: J. Hauke/AGE/Fotostock

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Small bottom-dwelling macroinvertebrates are major parts of the diet of the Platypus.

Considered an opportunistic forager, Platypuses readily take advantage of seasonal hatchings of aquatic insect nymphs and larvae; analyses of cheek-pouch contents indicate a preference for mayflies (Ephemeroptera), dragonflies (Odonata), stoneflies (Plecoptera), and caddisflies (Trichoptera). The Platypus will also consume adults of small freshwater crustaceans, like the common yabby (Cherax destructor) captured by the male shown here, as well as other free-swimming species such as water beetles (Coleoptera) and aquatic bugs (Hemiptera). The Platypus occasionally feeds on tadpoles, aquatic snails, and small fish. Food items placed in cheek pouches during foraging dives are masticated when the Platypus surfaces. In adults, teeth consist of keratinous pads adjacent to the cheek pouches. These pads are continuously replaced as they wear down from grinding food.

Despite its streamlined body, powerful muscular limbs with webbed feet, and insulating pelage, the cost associated with feeding and swimming in cold water is not trivial for the Platypus. The use of the forelimbs for propulsion through the water rather than kicking with the hindfeet is less efficient, and the buoyancy resulting from trapped air in the pelage increases the energy demands of diving. The tail of the Platypus primarily serves the purpose of a fat storage area, holding up to 40% of the total body fat. The tail can be an indicator of body condition and has been observed to thin over the winter and during lactation in females. When startled the Platypus dives with an audible splash that is not heard during normal foraging dives, however, it is not know if this is used as a warning signal to other Platypuses in the area. There is no evidence of Platypuses using sound to communicate in the wild.

PLATE 7

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59

60

61

62

63

64 variants

inches

6

cm

15

Plate 7 Species Accounts

Genus PHILANDER Brisson, 1762

58. South-eastern Four-eyed Opossum Philander frenatus French: Opossum bridé / German: Südöstliche Vieraugenbeutelratte / Spanish: Filandro de Brasil

Taxonomy. Didelphys frenata Olfers, 1818, “Südamerica.” Restricted by J. A. Wagner in 1843 to Bahia, Brazil.

This species is monotypic.

Distribution. SE Brazil, from Bahia S (including Minas Gerais and Goiás inland) to E Paraguay and N Argentina.

Descriptive notes. Head–body 26·5– 32·7 cm, tail 25·3–32·6 cm; weight 220– 910 g. Dorsal fur and body sides of the South-eastern Four-eyed Opossum are dark gray, and there is no mid-dorsal stripe. Head is dark gray, with small creamywhite supraocular spots. Tail length is about the same as head–body length; tail has fur on proximal 17% of its length and is whitish on distal one-third of its naked part.

Ventral fur is creamy-gray to white, gray-based on throat, and there is a narrow ventral strip of cream to whitish fur. Fur is short, dense, and smooth. Feet are reddish-brown or dark gray, and ears are large and pinkish, with blackish borders and undefined creamy white fur at their bases. Females have a complete pouch that opens forward, with 5–9 mammae, 2–4 on each side and a medial mamma. The South-eastern Foureyed Opossum has a 2n = 22, FN = 20 karyotype, with all acrocentric autosomes, an acrocentric X-chromosome and a minute Y-chromosome. Skull size and shape are sexually dimorphic.

Habitat. Mainly Atlantic Forest.

Food and Feeding. Diet of the South-eastern Four-eyed Opossum has been well studied at a number of sites, mainly in south-eastern Brazil. It feeds mainly on arthropods and small vertebrates, supplementing its diet with fruits. In a restinga forest in southeastern Brazil, it most frequently consumed Coleoptera, Hymenoptera, and Arachnida, followed by Diplopoda, Diptera, Isoptera, Orthoptera, Blattodea, and Hemiptera.

Vertebrate taxa consumed included rodents such as the Cursorial Akodont (Akodon cursor), lizards (Ameiva and Tropidurus), skinks (Mabuya), and birds. Fruits of c.30 types, such as Anthurium (Araceae), Achmaea (Bromeliaceae), Erythroxylum (Erythroxylaceae), Passiflora (Passifloraceae), Paulinia (Sapindaceae), and Pilosocereus (Cactaceae), are consumed more frequently during drier months, probably as a water supplement.

Its diet in a rural area in the mountains near Rio de Janeiro is also composed of arthropods, vertebrates, and fruits, but in this more mesic habitat, fruits are consumed according to availabilities and not related to precipitation. In another lowland Atlantic Forest site, still in Rio de Janeiro, its diet included Coleoptera, Hymenoptera, Arachnida, Diptera, unidentified rodents, and seeds (Piper, Piperaceae) in one study. Another study reported arthropods in 85·7% of the samples and vertebrates in 25·7% of them, including Ingram’s Squirrels (Sciurus aestuans ingrami), forest rats (Delomys), hocicudos (Oxymycterus), short-tailed opossums (Monodelphis), and an unidentified species of primate. There were seeds in 65·7% of the samples, with 13 morphotypes, including families Melastomataceae, Moraceae, Piperaceae, and Poligonaceae. In southern Brazil, South-eastern Four-eyed Opossums feed mostly on invertebrates, which were found in all fecal samples analyzed. Vertebrate remains were recorded in c.50% and seeds in c.29% of samples. Consumed invertebrates included Coleoptera, Opiliones, Diplopoda, Blattodea, Hymenoptera (ants), snails, Orthoptera, and Decapoda. Vertebrates recorded included unidentified birds, mammals, and lizards, and there were seeds of Monstera adansonii (Araceae), Ficus luschnathiana (Moraceae), and other unidentified Solanaceae. Nutritional contents of preferred diets, determined with cafeteria experiments in captivity where individuals were free to choose food items according to their needs, resulted in 10·6 g of proteins, 11·5 g of carbohydrates, 2·3 g of lipids, and 1·8% of fibers per 100 g of dry matter.

Breeding. Female South-eastern Four-eyed Opossums make nests under trees, with entrance tunnels, but they also nest as high as 8–10 m in hollow trees or tree forks.

Captive individuals had a gestation of 13–14 days, and females exhibited post-lactation estrus but no sign of male-induced estrus. Weaning occurred at 70–80 days. Mean litter size in captivity was 5·5 young. Reported litter sizes in the wild were 1–8 young, with a modal number of eight young in an Atlantic Forest site, 5·7 (5–7 young) in another Atlantic Forest site, and 4·5 in yet another Atlantic Forest site (with a maximum of seven young recorded). Mean of 5·3 young/litter was recorded in a restinga forest. Breeding season lasted from July or August to April at several study sites in Rio de Janeiro (both rural Atlantic Forest sites) and July–February in a restinga forest. In another Atlantic Forest site in Rio de Janeiro, reproductive females were found throughout the year, and their occurrence was not linked to rainfall. Breeding season is September–February in Minas Gerais and August–February in Misiones, Argentina.

Activity patterns. There is no specific information available for this species, but the South-eastern Four-eyed Opossum is reported to be nocturnal.

Movements, Home range and Social organization. South-eastern Four-eyed Opossums move mostly on the ground, but they climb well, and when they do, they mostly

use understory, as determined by spool-and-line tracking. They can jump across gaps and may locate nests as high as 10 m. Estimated home ranges vary widely, depending on method used, from an average of 0·4 ha to up to 12 ha. In the same or nearby sites in lowland Atlantic Forest in Rio de Janeiro, home range of the South-eastern Four-eyed Opossum averaged 2·8 ha (range 0·6–7·4 ha) using radio-telemetry or 2 ha (0·1–12·1 ha) using capture-mark-recapture with multiple grids. Nevertheless, mean estimates of home ranges using a single grid were much lower: 0·4 ha (0·12–1 ha) was reported in a restinga forest in Rio de Janeiro, 0·4 ha (0·14–0·64 ha) in an Atlantic Forest site in São Paulo, and 0·67 ha in an Atlantic Forest site in Rio de Janeiro. In a restinga forest, densities were 191 ind/km2. Perceptual range of the South-eastern Four-eyed Opossum (maximum distance at which they can detect a landscape element) is 100 m, based on abilities of individuals released in a grass matrix to detect and head for forest fragments from which they had been removed; however, this distance depends on vegetation obstruction and decreases to 50 m in tall grass (c.50 cm) and 30 m in plantations. South-eastern Four-eyed Opossums can use low grass matrix to move between fragments and showed homing behavior, choosing to return to the fragment from which they were collected, even if it was farther away than other fragments. In a restinga forest, the most frequent movements were less than 30 m, with occasional movements of up to 300 m. Estimates using spool-and-line devices in the Atlantic Forest of south-eastern Brazil yielded similar values, with distances between successive captures of 20–83 m and maximum distances traveled of 156 m.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Southeastern Four-eyed Opossum has a wide distribution and presumably a large overall population; it occurs in several protected areas and is tolerant of various levels of habitat modification. Although it requires forested habitat, it seems to tolerate some level of fragmentation fairly well because populations living in Atlantic Forest fragments in south-eastern Brazil use edge and interiors of fragments and forage in surrounding matrices or move across fragments.

Bibliography. Astúa (2010), Astúa, Lemos & Cerqueira (2001), Astúa, Santori et al. (2003), Barros et al. (2008), Beisiegel (2006), Bergallo (1994), Biggers et al. (1965), Bonecker et al. (2009), Cáceres (2004, 2005), Carvalho, B.A. et al. (2002), Carvalho, F.M.V. et al. (1999), Castro-Arellano et al. (2000), Ceotto et al. (2009), Cerqueira et al. (1993), Chemisquy & Flores (2012), Crouzeilles et al. (2010), Cunha & Vieira (2002), D’Andrea, Cerqueira & Hingst (1994), D’Andrea, Gentile, Cerqueira et al. (1999), D’Andrea, Gentile, Maroja et al. (2007), Davis (1947), Delciellos & Vieira (2006, 2007, 2009a, 2009b), da Fonseca, G.A.B. & Kierulff (1989), Fonseca, S.D. & Cerqueira (1991), Forero-Medina & Vieira (2009), Gardner (2005), Gentile & Cerqueira (1995), Gentile, D’Andrea & Cerqueira (1995, 1997), Gentile, Finotti et al. (2004), Hingst et al. (1998), Lira & Fernandez (2009), Lira et al. (2007), Macedo, Loretto et al. (2007), Macedo, Fernandez & Nessimian (2010), Mendel & Vieira (2003), Miles et al.

(1981), Nunes et al. (2006), Paresque et al. (2004), Passamani (1995, 2000), Patton & Costa (2003), Patton & da Silva (1997, 2008), Pereira et al. (2008), Pires et al. (2002), Prevedello, Delciellos & Vieira (2009), Prevedello, Forero-Medina & Vieira (2010, 2011), Redford & Eisenberg (1992), Reig et al. (1977), Santori, Astúa & Cerqueira (2004), Santori, Astúa, Grelle & Cerqueira (1997), Smith (2009a), Talamoni et al. (1999), Vieira (1997), Vieira & Cunha (2008), Voss & Jansa (2012), Wagner (1843).

59. Anderson’s Four-eyed Opossum Philander andersoni French: Opossum de l’Orénoque / German: Andersons Vieraugenbeutelratte / Spanish: Filandro de Anderson Other common names: Black Four-eyed Opossum

Taxonomy. Metachirus andersoni Osgood, 1913, “Yurimaguas, [Loreto], Peru.”

This species is monotypic.

Distribution. SE Colombia, SC Venezuela (Bolívar, Amazonas), W Brazil (Amazonas, Acre), E Ecuador, and N & C Peru (S to Ayacucho) E of the Andes.

Descriptive notes. Head–body 22·3– 30·7 cm, tail 25·5–33·2 cm; weight 225– 600 g. Dorsal fur of Anderson’s Four-eyed Opossum is dark gray, and there is conspicuous mid-dorsal black stripe c.3–4 cm wide from neck to base of tail, contrasting with gray body sides. Head has creamy cheeks and large, distinct creamy supraocular spots; there is no mid-rostral stripe. Tail length is c.110% of head–body length, tail has fur on c.18% of its length, and distal one-third of naked rest of tail is white. Ventral fur is creamy to gray-based or pale gray. Fur is dense and c.10 mm long. Feet are black, and ears are pale brown, with a pale cream spot at their bases. Females have a complete pouch that opens forward, with seven mammae, three on each side and a medial mamma. Karyotype of Anderson’s Four-eyed Opossum is unknown. Skull shape is sexually dimorphic.

Habitat. Mature and disturbed lowland Amazonian rainforest.

Food and Feeding. There is no information available for this species.

Breeding. In Peru, a young female Anderson’s Four-eyed Opossum was collected with four pouch young in March, and a slightly older female was collected in July. Nursing females with litters of two young were captured in April and October in Peru, and three other nursing females, two with litters of four young and the other with a litter of two young, were captured in March, May, and July.

Activity patterns. There is no specific information available for this species, but Anderson’s Four-eyed Opossum is reported to be nocturnal.

On following pages: 60. Orinoco Four-eyed Opossum (Philander deltae); 61. McIlhenny’s Four-eyed Opossum (Philander mcilhennyi); 62. Mondolfi’s Four-eyed Opossum (Philander mondolfii); 63. Olrog’s Four-eyed Opossum (Philander olrogi); 64. Gray Four-eyed Opossum (Philander opossum).

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FAMILY DIDELPHIDAE Opossums

FAMILY CAENOLESTIDAE Shrew Opossums

The Incan Shrew Opossum is the only species in the genus Lestoros.

It is known from the east slope of the central Andes, from southeast Peru to western Bolivia.

Its dentition, in particular, differs markedly from that of Caenolestes species and its snout and jaw are shorter than in both the other shrew opossum genera.

Incan Shrew Opossums appear to favor drier, lower-elevation habitats with more shrubs and grasses than do Caenolestes species, which typically occupy moist upper montane forests, such as cloud forest and wet elfin forest.

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Lestoros inca La Esperanza, Cuzco, Peru.

Photo: Bruce D. Patterson/ Mammal Image Library of the American Society of Mammalogists

to be homologous with the second lower incisor of didelphoids and other marsupials, whereas the procumbent tooth in diprotodonts is derived from the lower third and fourth incisors. The upper and lower molar series of shrew opossums diminishes in size from the first molar to the third molar, with the fourth molar still further reduced. The dental formula is I 4/3, C 1/1, P 2–3/3, M 4/4 (× 2) = 44–46. An antorbital vacuity, at the juncture of the nasal, frontal, and maxillary bones, is usually open and prominent. The upper and lower lips have distinct fleshy flaps of skin superficial to the cheek teeth. The digits on the hindfoot are not syndactylous (webbed).

A superficial thymus is present, the stomach has three compartments, and the forebrain lacks a fasciculus aberrans (a part of the forebrain contributing to the anterior commissure, or tissue connecting the hemispheres of the brain). Pairing of spermatozoa occurs in the epididymes of shrew opossums and didelphoid marsupials but in no other marsupial group. In shrew opossums, the sperm head is rectilinear, not ovoid as in didelphimorphs, and pairing takes place across the flattened rostral surface. A 14-chromosome karyotype characterizes all shrew opossums sampled to date, providing further evidence that this karyotype is primitive for Metatheria and reinforcing the pattern of low karyotypic variation within families found in other marsupial orders.

The Condor Shrew Opossum is the largest known species of shrew opossum, with a skull length of more than 36 mm.

In most species of shrew opossums, males are somewhat larger than females. Species of northern shrew opossums (Caenolestes) are generally the largest, with maximum-recorded weights ranging from 45 g for the Blackish Shrew opossum to 53 g for the Sangay Shrew Opossum. The Dusky Shrew Opossum is often reported to be the smallest species of Caenolestes, with

weights of 25–32 g, but it is quite comparable in weight to the Incan Shrew Opossum (20–35 g) and the Long-nosed Shrew Opossum (23–30 g).

Habitat Shrew opossums occupy habitats from sea level in Chile to at least 4300 m in the northern Andes. Typical habitats are moist temperate forests, often filled with mosses and bryophytes, but shrew opossums also occur on the páramos (high-elevation grasslands) of the northern Andes, where they inhabit the dense undergrowth of scrub forest abutting the open grasslands. They frequently inhabit the ledges and tangled galleries formed by tree roots on steep mosscovered slopes, which are linked by holes and runways to other such ledges. Incan Shrew Opossums appear to favor drier, low-elevation habitats with more shrubs and grasses than do the other genera.

General Habits Shrew opossums are terrestrial and nocturnal or crepuscular.

Their vision is poor, judging from their small eyes, orbits, and optic nerves, but their sense of smell is very well developed, with a very large snout (four large ethmoturbinals and one nasoturbinal), large olfactory bulbs, and an olfactory tubercle. Shrew opossums also have acute hearing, aided by large pinnae and large inner ears, and touch, especially through sensory vibrissae on their snouts and cheeks, which are innervated by a greatly enlarged superior maxillary branch of the trigeminal nerve. The feet and limbs of shrew opossums

FAMILY CAENOLESTIDAE Shrew Opossums

Unlike those of other shrew opossums, the tail of the Longnosed Shrew Opossum swells seasonally with fat stores, expanding from 4–5 mm in diameter during summer, to 9–11 mm in early winter. The specific name raphanurus (“radish-tail”) refers to this feature.

The tail is equivalent to only two-thirds of body length, whereas in other species in this family, body and tail lengths are similar.

The only species in the genus Rhyncholestes, the Long-nosed Shrew Opossum has a head that is narrow and more elongated than in other shrew opossum genera.

It is the southernmost of the shrew opossums, found in south-central Chile and adjacent Argentina, and on Chiloe Island.

Rhyncholestes raphanurus La Picada Forest Preserve, Osorno, Chile.

Photo: P. L. Meserve/ Mammal Image Library of the American Society of Mammalogists

The Sangay Shrew Opossum appears to share insectivorous habits of other species of shrew opossums. Shrew opossums appear to be opportunistic, omnivorous feeders, and their diets include many kinds of insects and their larvae, earthworms, spiders, scorpions, small vertebrates, and fruits and fungi. They locate their food by continually poking their muzzles into moss and litter among tree roots and on the forest floor.

Food items may be held between the forepaws while the shrew opossum sits up on its hindlegs and tail to eat them.

Caenolestes sangay Tinguichaca, Sangay National Park, Morona-Santiago, Ecuador.

Photo: Reed Ojala-Barbour

Communication Practically nothing is known of social interactions of shrew opossums. Three vocalizations are known, but the context in which they are uttered is murky. The first is the typical marsupial hiss, usually taken as a distress call. The second is a squeak, like that of a rat, but lower pitched. The third is a sound produced by drawing air in and out between the lower incisors.

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are adapted to a terrestrial lifestyle and are ill-suited to climbing or prehensile use, despite prior suppositions that these animals might be partly arboreal. When exploring, their actions are jittery. Shrew opossums constantly poke their muzzles into the litter and moss in search of food. When alarmed, they run off rapidly, bounding on all fours; when cornered, they rear back and open their mouths, hissing with the tongues extended.

PLATE 13 inches

2

cm

5

1

2

FAMILY NOTORYCTIDAE Marsupial Moles

Plate 13 Species Accounts

Genus NOTORYCTES Stirling, 1891

1. North-western Marsupial Mole Notoryctes caurinus French: Kakarratul / German: Kleiner Beutelmull / Spanish: Topo marsupial septentrional

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Other common names: Kakarratul, Northern Marsupial Mole, Western Marsupial Mole

Taxonomy. Notoryctes caurinus O. Thomas, 1920, “Wollal [= Wallal], N.W. Australia.”

This species is monotypic.

Distribution. Sandy deserts of NW Australia (Western Australia), including Gibson, Little Sandy, and Great Sandy deserts, and possibly parts of the Tanami Desert, and approaching the coast in the hinterland of the Eighty Mile Beach between Port Hedland and Broome.

Descriptive notes. Head–body 8·6– 9·3 cm, tail 1·6–1·8 cm; weight 30–50 g. The North-western Marsupial Mole is slightly smaller and of more slender build than its relative, the Central Desert Marsupial Mole (N. typhlops). Two large claws on forelimb of the North-western Marsupial Mole are consistently narrower, rhinarial pad is smaller in height and width, and tail is narrower at its base. Cranium of the North-western Marsupial Mole is smaller than that of the Central Desert Marsupial Mole and has a proportionally shorter rostrum and larger auditory bullae. In upper dentition of the North-western Marsupial Mole, last molar (M4) is more reduced in size and complexity than in the Central Desert Marsupial Mole. Lower dentition features a reduction in tooth number in incisor-to-premolar region, with three small, single-rooted teeth present rather than 4–5 teeth. Notable features of postcranial anatomy of the North-western Marsupial Mole include a reduced number of ribs (14 rather than 15 in the Central Desert Marsupial Mole), a loss of one sternal segment (five rather than six sternebrae between manubrium and ziphoid cartilage), and an even greater reduction of epipubic element to thin cartilaginous rod (small but ossified in the Central Desert Marsupial Mole).

Habitat. Sandy habitats including extensive tracts of linear dune-field, areas of parabolic dune complexes, and sandy washouts of ephemeral watercourses, with spinifex (Triodia, Poaceae) hummock grassland and a variable shrub layer of acacias (Acacia, Fabaceae) and other woody plants. The North-western Marsupial Mole has been collected at fewer than 15 localities in Gibson, Little Sandy, and Great Sandy deserts of Western Australia; however, information from Aboriginal informants suggests a much broader distribution that probably takes in c.30% of the land area of Western Australia—a huge and largely unpopulated area. At the south-eastern extremity of its distribution, in the vicinity of the Warburton Range, the North-western Marsupial Mole may occur in regional sympatry or syntopy with the Central Desert Marsupial Mole.

Food and Feeding. The diet of the North-western Marsupial Mole has not been studied either in the field or from examination of gut contents. A captive individual held in the laboratory of P. Withers of the University of Western Australia initially proved difficult to maintain, although it later seemed to feed avidly on large insect larvae collected from the stems of dead grass trees (Xanthorrhoea sp., Xanthorrhoeaceae).

Mealworm larvae (Tenebrio molitor, Tenebrionidae) were refused. The individual inexplicably stopped eating and died after five weeks in captivity.

Breeding. There is no specific information available for this species, but if the specimen in the South Australian Museum from Sturt Creek in Western Australia is a Northwestern Marsupial Mole, then it provides a record of twin pouch young.

Activity patterns. The only information on activity patterns of the North-western Marsupial Mole comes from observations on a single captive individual that was maintained for five weeks. Its general behavior conformed to reports on captive Central Desert Marsupial Moles. Whether above or below the surface, it alternated between bouts of frenetic activity and periods of immobility during which it appeared to be asleep. When brought to the surface, it usually burrowed again rapidly.

Movements, Home range and Social organization. Trackways made by the Northwestern Marsupial Mole lack central tail drag mark, and it is assumed that they hold the tail off the ground while walking or running. More detailed information on locomotion and burrowing ability come from observations on a single captive individual. This individual was unable to burrow into dry sand because any excavation filled with sand as fast as it was removed. Burrowing became possible only when sand was moistened, thereby providing some cohesion. During initial burrowing, the tail was used to brace the body as head and forelimbs were plunged downward into the sand. When placed in an experimental rotating chamber full of dry sand, the individual could sand-swim successfully. Energetic cost of sand swimming is similar for the marsupial mole (81 J/m) and the Namib Golden Mole (Eremitalpa granti namibensis; 73 J/m), which shows a high degree of morphologically convergence.

Nevertheless, the Namib Desert Golden Mole burrows through sand considerably faster (15–40 m/h) than the marsupial mole (2–18 m/h), which is thus a relatively inefficient sand swimmer under the test conditions. Withers and coworkers described the surface gait of the captive North-western Marsupial Mole as “a slow and seemingly laborious shuffling action.” Nevertheless, running could be maintained for more than 60 minutes at a remarkably constant average speed of 484 m/h (range = 319–688 m/h). Metabolic rate of the marsupial mole was similar whether it was running or sand swimming. Because much higher speeds were achieved during surface running than during sand swimming, the former is a much more energy efficient (1·4 J/m compared to 81 J/m for sand swimming). If these values are at all representative of the natural energetic regime of a free-living marsupial mole, it can only be presume that individuals are able to encounter prey items in sufficiently quantities below ground and, furthermore, that this “high-cost” lifestyle is rewarded by safety from predation. Nevertheless, sand swimming along sand-filled tunnels may require much less energy if an individual is able to obtain purchase on the walls or roof of the tunnel through use of its front claws, tail, and ischiotergal patch on its lower back. No information is available on home range or social organization of the North-western Marsupial Mole.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. A recent assessment by A. Burbidge and coworkers in 2014 recommends a conservation status of least concern. Each known locality for the North-western Marsupial Mole has yielded only 1–2 specimens, and there is nothing to match the large singlelocality samples available for the Central Desert Marsupial Mole. While this might reflect a genuine ecological contrast in abundances between the two species, it is more prudent to conclude that it represents circumstances of collecting. All capture records of North-western Marsupial Moles since 1990 come from localities in the north-western part of its distribution. This is an area of active resource development, and several North-western Marsupial Moles have been uncovered during road construction.

Bibliography. Benshemesh (2004), Benshemesh & Aplin (2008), Benshemesh & Burbidge (2008), Burbidge & Aplin (1996), Burbidge et al. (1988), Maxwell et al. (1996), Thomas (1920b), Thompson et al. (2000), Troughton (1973), Warburton (2006), Warburton et al. (2003), Withers et al. (2000), Woinarski et al. (2014h).

Plate 13 Species Accounts

2. Central Desert Marsupial Mole Notoryctes typhlops French: Itjari-itjari / German: Großer Beutelmull / Spanish: Topo marsupial meridional Other common names: Central Marsupial Mole, Itjaritjari, Southern Marsupial Mole

Taxonomy. Psammoryctes typhlops Stirling, 1889, “Indracowie Cattle Station … about 100 miles from the Charlotte Waters Telegraph Station,” central Australia.

E. C. Stirling provided the first description of this species and its type locality, as commonly appears, in 1888, one year before he gave it its scientific name. Specimens from around Ooldea in the southern part of the distribution of this species are, on average, larger in external body and cranial measurements than those from around the type locality in central Australia, and a degree of differentiation between the two regional populations is also indicated by as yet unpublished mitochondrial sequence data. Further work is needed to resolve significance of these contrasts. Monotypic.

Distribution. Sandy deserts of C Australia (S Northern Territory, SE Western Australia, and W South Australia), including portions of the Great Victoria, Tanami, and Great Sandy deserts, and possibly parts of the Simpson Desert; it also occurs in sandy tracts within the desert uplands around Alice Springs, S Northern Territory.

Descriptive notes. Head–body 11–14 cm, tail c.2–2·5 cm; weight 50–60 g. The Central Desert Marsupial Mole is a larger and stockier species than the North-western Marsupial Mole (N. caurinus). Two large claws on forelimb are consistently broader than on its north-western relative, rhinarial pad is taller and wider, and tail is broader at its base.

Cranium of the Central Desert Marsupial Mole is larger than that of the North-western Marsupial Mole and has a proportionally longer rostrum and smaller auditory bullae.

In upper dentition, last molar (M4) is larger and possesses more discrete cusps than corresponding tooth in the North-western Marsupial Mole. In lower dentition, 4–5 small, single-rooted teeth are present in incisor-to-premolar region, rather than three teeth. Notable features of postcranial anatomy of the Central Desert Marsupial Mole include a larger number of ribs (15 rather than 14 in the North-western Marsupial Mole), a larger number of sternal segments (six rather than five sternebrae between manubrium and ziphoid cartilage), and a lesser degree of atrophy of the epipubic that is small but bony rather than cartilaginous. Virtually all of the detailed anatomical knowledge of Notoryctes comes from studies of the Central Desert Marsupial Mole.

Habitat. Sandy substrate, most often in linear dunes or sand plains and probably also parabolic dune complexes and sandy washouts of ephemeral watercourses, with hummock grassland dominated by species of Triodia or Plectrachne (both Poaceae) and often shrub layer of acacias (Acacia, Fabaceae) and casuarinas (Casuarina, Casuarinacaea). In linear sand dune country, Central Desert Marsupial Moles appear to favor dune flanks and crests and avoid the hard loamy sediments of the dune swales. On the western margin of its distribution, in the vicinity of the Warburton Range, the Central Desert Marsupial Mole may occur in regional sympatry or syntopy with the Northwestern Marsupial Mole.

Food and Feeding. Information on the diet of the Central Desert Marsupial Mole comes from attempts to maintain them in captivity and from analysis of gut contents of museum specimens. Captive individuals have accepted numerous food items including eggs, larvae, and pupae of various insect species including ants and termites, earthworms, centipedes, spiders, and gekkonid lizards. Larvae of longicorn beetles (Cerambycidae) and scarab beetles (Scarabaeidae), moths (Lepidoptera), and commercial mealworms (larvae of Tenebrio molitor, Tenebrionidae) have been acceptable food items, but adult beetles seem to be rejected. B. Spencer reported his captive Central Desert Marsupial Moles fed readily on ant eggs, larvae, and pupae, but he postulated that adult ants are ingested coincidentally. F. Wood Jones found earthworms (Lumbricus sp., Lumbricidae) to be acceptable to captive Central Desert Marsupial Moles, but others have had the opposite experience. At any rate, earthworms are not usually available in the sandy desert environment occupied by Central Desert Marsupi-

al Moles. There are no observations of feeding above ground by free-living Central Desert Marsupial Moles. Captive individuals will sometimes feed above ground, but they more often grasp large prey items in the mouth and burrow underground to consume them. Small food items like ant or termite eggs are simply licked from the surface, but larger items may be held down or sometimes suspended by forelimbs while they are grasped in the mouth or chewed. Reduction of large food items appears to take place through progressive reduction in the posterior premolar and molar region, and there is no attempt to tear off pieces of food. Gut contents of Central Desert Marsupial Moles have contained a variety of invertebrate prey items and some plant material, most often grass seeds. A specimen examined by C. Brazenor in the mid-1950s contained burrowing sawfly larvae (Pergidae), ants of the genus Rhytidoponera (Ectatomminae), and legs of leaf beetles (Chrysomelidae). K. Winkel and I. Humphrey-Smith examined ten specimens of Central Desert Marsupial Moles and found remains of adult predatory ants (Iridomyrmex spp., Dolichoderinae), seed-eating ants (Myrmeciinae), and their eggs, larvae, and pupae. Grass seeds were also present, but these may have been ingested accidentally from underground caches maintained by Myrmeciinae. More recently, C. Pavey and coworkers examined gut contents of 16 Central Desert Marsupial Moles and compared prey abundances in soil cores taken on sand ridges in the general region of original capture. Five insect orders (Coleoptera, Hymenoptera, Isoptera, Lepidoptera, and Orthoptera) were represented in gut samples, along with scorpions, spiders, and plant material. Two main prey types were dominant: social insects (ants and termites) and larvae of beetles. Ants, termites, and beetle larvae also dominated samples obtained in soil cores. Termites alone were potentially underrepresented in gut contents compared with their natural frequency. Results suggest that the Central Desert Marsupial Mole is a dietary generalist despite its specialized adaptations for a subterranean lifestyle.

Breeding. Instances of single and twin pouch young have been recorded for the Central Desert Marsupial Mole. Although only two teats are present in the pouch, the uterus of one pregnant female contained six subterminal fetuses along with two degenerating blastocysts, suggesting a degree of embryonic wastage that is unusual among Australian marsupials. Otherwise, there is no information on timing of mating, duration of pregnancy, and processes of birth and development of the Central Desert Marsupial Mole.

Activity patterns. There has been much speculation regarding timing and environmental correlates of surfacing behavior of the Central Desert Marsupial Mole, but none of the hypotheses are supported by any field data. Surfacing may take place primarily in the evening when soil surface temperatures are dropping but before night air temperatures fall dramatically. Some individuals located on the surface during the day seem to have been moribund while others may have been forced to the surface by high groundwater after flooding. Otherwise, nothing is known about activity patterns of free-living Central Desert Marsupial Moles.

Movements, Home range and Social organization. A Central Desert Marsupial Mole engaged in surface walking or running shows that the forelimb and hindlimb of one side are extended in unison, the claw on the forelimb being used to haul the individual along the surface while the collateral hindlimb is extended to provide additional propulsive force. The result is that the individual proceeds with a rapid sinuous shuffle.

Nothing is known about home range size, territoriality, or other social organization or behaviors of the Central Desert Marsupial Mole.

Status and Conservation. Classified as Data Deficient on The IUCN Red List. In a recent assessment, A. Burbidge and coworkers in 2014 recommend a conservation status of least concern for the Central Desert Marsupial Mole. There are recent records from several localities in central Australia and one from the Great Victoria Desert. Burrows of Central Desert Marsupial Moles have been found in many more localities, but it is unclear how populated some sites are and how long these burrows may persist within the soil profile.

Bibliography. Bennison et al. (2014), Benshemesh (2004, 2008, 2014), Benshemesh & Johnson (2003), Beveridge & Durette-Desset (1985), Burbidge & Aplin (1996), Burbidge et al. (1988), Corbett (1975), Dennis (2004), Dickman, Burbidge et al. (2008), Finlayson (1961a), Howe (1975), Johnson (1995), Johnson & Walton (1989), Jones (1924), Maxwell et al. (1996), Paltridge (1998, 2002), Pavey et al. (2012), Pearson & Turner (2000), Stirling (1888, 1889), Winkel & Humphrey-Smith (1988), Woinarski et al. (2014g).

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FAMILY NOTORYCTIDAE Marsupial Moles

FAMILY DASYURIDAE Carnivorous Marsupials

A study of the diet of the Fattailed Dunnart in western New South Wales found that spiders (Araneae) were the main prey, comprising 53% of invertebrates consumed. Hymenoptera (mainly ants) and Orthoptera (mainly crickets) were also heavily preyed upon. Juicy prey such as cockroaches and spiders is preferred during drought periods, and beetles at other times. Small vertebrates are taken only rarely, and appear to be hunted using both sight and sound. This species will use the cover of night to forage on the ground in bare open areas.

Sminthopsis crassicaudata Goongarrie National Park, Western Australia, Australia.

Photo: Jiri Lochman/Lochman Transparencies

ing a second estrus in the same breeding season if she does not secure a mate or loses her first litter. There is no evidence of suicidal mating in Category III species as in Category I species; indeed, some male and female Category III dasyurids live for more than three breeding seasons. Interestingly, Northern Quolls are facultatively Category I breeders in some populations, and the reason for this is unclear. During the mating period, male Northern Quolls regularly visit several females in succession to monitor the onset of estrus. The intense physical effort appears to be at least a partial cause of the physiological decline of males and subsequent die-off at one year of age in some populations, because captive males can live for up to six years. Eastern Quolls are also examples of a Category III dasyurids. Female Eastern Quolls in Tasmania breed synchronously

in winter of each year, but in a more northerly population in New South Wales, they are polyestrous, bearing young in winter and spring pulses. It is unclear why these populations behave differently, but it is noteworthy that quolls are mostly meat-eaters (rather than insectivores), so the likelihood of their securing food is not as seasonally restricted. Mothers bearing second litters are perhaps more likely to secure food and thus not lose the litter. Category III species often co-occur with Category I and II species.

Category IV. Sexual maturity of Category IV dasyurids is achieved at 8–11 months of age, and the breeding season is extended, lasting up to six months and typically occurring between winter and summer. Interestingly, neither sex breeds in the season of its birth, but when they begin breeding, females

240

With a combination of fearlessness and extraordinary agility, even the smallest dasyurids will attack large, dangerous prey such as spiders, scorpions, and centipedes.

However, studies have shown that prey-handling time can increase exponentially with prey size, so prey selection becomes a trade-off for the predator regarding chance of success, time for consumption, and risk of injury. A study of 21 dasyurid species, including the Little Long-tailed Dunnart, found that individuals of the smaller species in captivity maximized energy gain by feeding preferentially on small prey. In contrast, larger dasyurids preferred large prey, and obtained a greater rate of energy gain from them.

Sminthopsis dolichura Toolonga Nature Reserve, Western Australia, Australia.

Photo: Jiri Lochman/Lochman Transparencies

FAMILY DASYURIDAE Carnivorous Marsupials

When attacking centipedes, dasyurids may vary their usual tactic of a killing bite to the head, to avoid a poisonous bite from the pincer-like forcipules. A Southern Ningaui (Ningaui yvonneae) was watched as it attacked a 6Â cm centipede from the rear, using a technique described as lunge-bite-retreat. Most bites were directed to its posterior section, and occasionally the mid-section.

This appeared to be a disabling maneuver. With the centipede disabled, the ningaui launched killing bites to its anterior segments. Arthropod exoskeletons vary in thickness and toughness, and can be a formidable barrier.

Insectivorous dasyurids tend to have many small, sharp cutting edges on the tooth, but the cuticle of larger insects (such as desert beetles) may prove too tough for the smallest insectivores to pierce.

One experiment which examined the prey selection of six dasyurids, including the Wongai Ningaui and Southern Ningaui, found that neither of these species ate beetles with hard cuticles. Both ate more soft-shelled beetles and spiders than expected from their availability, suggesting that they were the least generalist of the six species, which also including three dunnarts (Sminthopsis) and the Crestedtailed Mulgara (Dasycercus cristicauda). However, both ningaui species were found to forage along trails where soft prey was most commonly encountered, and hard beetles rarely to be found.

By contrast, the Crested-tailed Mulgara encountered a high proportion of hard beetles along its foraging trails, and was the only one of the six species to include them regularly in its diet.

241

Ningaui ridei Goongarrie National Park, Western Australia, Australia.

Photos: Jiri Lochman/Lochman Transparencies

PLATE 18

40

inches cm

39

42 41 43

44

45

46

47

53

48

54 52

49 ssp laniger

50 51

55 ssp spenceri

4 10

Plate 18 Species Accounts

Genus MUREXIA Tate & Archbold, 1937

39. Habbema Dasyure Murexia habbema French: Murexie du Habbema / German: Habbema-Neuguinea-Beutelmaus / Spanish: Dasiuro del Habbema Other common names: Habbema Antechinus

Taxonomy. Antechinus habbema Tate & Archbold, 1941, 9 km N of Lake Habbema, North Slope of Mt. Wilhelmina, 2800 m, Prov. of Papua (= Irian Jaya), Indonesia.

Acceptance of the trans-Torresian distribution of Antechinus prevailed until 1984.

At this time, P. A. Woolley’s work on male phallic morphology indicated a dubious relationship between Australian and New Guinean members of Antechinus and thus challenged integrity of Phascogalinae. Antechinus in Australia, meanwhile, was no longer considered monophyletic, including at that time what we now regard as Dasykaluta rosamondae, Pseudantechinus macdonnellensis, P. ningbing, P. bilarni, and Parantechinus apicalis. This was followed by work clarifying species applicable to the “antechinus” of New Guinea (melanurus, habbema, and naso).

This research indicated New Guinean species deserved generic reclassification; their inclusion in Antechinus was, as Woolley had suggested, inappropriate. DNA hybridization and albumin immunology studies confirmed the closer relationship among New Guinea species than with Australian Antechinus. Subsequent direct DNA work suggested that New Guinea taxa were sister to Australian antechinuses. Then, in 2002, S. Van Dyck’s landmark morphological study of Australian and New Guinean “antechinuses” concluded that New Guinea taxa assigned to Antechinus (pre-1984) represented three related but morphologically primitive taxa that lacked clear signs of close relationship. They were thus referred to five genera. Monotypic Micromurexia (habbema), Phascomurexia (naso), and Murexechinus (melanurus) are only distantly related to Australian antechinuses. New Guinea Murexia was thus rendered monotypic (M. longicaudata); morphologically, this taxon was viewed as having no especially close relationship with the more derived rothschildi, which was thus assigned to Paramurexia. Based on morphology, Australian Antechinus appeared to be monophyletic with Phascogale. Nevertheless, in the last decade additional independent DNA sequencing studies suggested that, notwithstanding distinctive morphological divergences in the group as clarified

by Van Dyck, genetic differences among New Guinean species are most parsimoniously consistent with recognition of a single genus, Murexia. Several phylogenetic analyses of these sequences consistently showed strong support for monophyly of Murexia with respect to other Phascogalines, Australian genera Antechinus and Phascogale, with uncertain status of sister relationships among the three. This is now the prevailing view, so a single genus, Murexia, for New Guinean “antechinus” fauna is adopted here. Yet, parsimony merely follows the shortest path, not necessarily the “best” one. Clearly, a comprehensive revision of the entire group, incorporating genetic and morphological data and a detailed sampling of the fauna in New Guinea, is required, especially because Australian Antechinus has recently been found to harbor numerous cryptic taxa, and the most recent work indicates there are also cryptic taxa residing within at least some of the five currently recognized species of Murexia. This revision is underway.

M. habbema was long considered to have been based on a mismatched skin and skull; the skin was purportedly comparable to Antechinus tafa centralis (currently M. naso) and the skull to Antechinus wilhelmina (currently M. melanurus). It was widely listed as a synonym of M. naso, but research by Woolley in 1989 and later an exhaustive morphological appraisal by Van Dyck indicated that it was a distinct species, distinguishable based on skull and external features. In 1952, E. M. O. Laurie described some specimens from the Tomba area in the Hagen Range at an elevation of 2500 m under the name Antechinus hageni. This has been synonymized with M. habbema, but there are still suggestions that they may be separate species. Recent work has indicated that M. habbema may represent two allopatric species; these are currently recognized as subspecies.

M. habbema has a wide distribution encompassing the Central Range of the island of New Guinea (Indonesia and Papua New Guinea). Two subspecies recognized.

Subspecies and Distribution.

M. h. habbema Tate & Archbold, 1941 – New Guinea, W Central Range [Maoke (= Snow and Star) Mts].

M. h. hageni Laurie, 1952 – New Guinea, E Central Range (from Mts Giluwe, Sisa, and Hagen to N Central Province in Papua New Guinea).

Descriptive notes. Head–body 11·2–12·2 cm (males) and 11–11·7 cm (females), tail 10·9–15·7 cm (males) and 11·9–14·3 cm (females); weight 28·4–45·4 g (males) and 22·7–31·2 g (females). The Habbema Dasyure is a medium-sized dasyurid that lacks stripes or spots. Its most distinctive feature is a crest of hairs running along ventral edge of tail. Ears lack post-auricular patches, and pelage is a more uniform shade throughout rather than the rufous post-auricular patches and definite warming of tones toward rump characteristic of some congeners. Claws of the Habbema Dasyure are slightly

curved and slender rather than strongly curved and thick; tail is dorso-ventrally bicolored rather than uniform black (although sometimes it is uniform dark brown).

Habitat. Montane primary forest, mid-montane forest, beech forest, mossy forest, and subalpine grasslands at elevations of 1600–3660 m. The Habbema Dasyure occurs in disturbed primary forest, but it is not present in secondary forest habitats.

Food and Feeding. Little is known about the diet and foraging patterns of Habbema Dasyures. One study examined diet of four wild-caught species of Murexia trapped on Mount Kaindi and Mount Missim on opposite sides of the Wau Valley in the Morobe Province of Papua New Guinea. Fifty-six individuals (28 male and 26 female) were captured. Habbema Dasyures caught on Mount Kaindi produced feces that contained, by percent frequency of occurrence in feces examined, 95% beetles, 87% spiders, 50% bugs, 41% moths and butterflies, 39% grasshoppers and crickets, 37% unidentified insects, 36% worms, and 6% vertebrates (including mammal hair).

Breeding. Habbema Dasyures nest in burrow systems in the ground. One study of 18 (seven males and eleven females) wild-caught Habbema Dasyures suggested that they might breed at any time of the year. This suggestion was supported by the incidence of lactating females, often at different stages of lactation, in most months when adult females were captured, and incidence of juveniles in the population. The Habbema Dasyure was not successfully bred in captivity (despite two attempted pairings), but wild-conceived young were kept in captivity, although none of them survived to weaning. Males had no evidence of a sternal gland, had a scrotal width of 9–12 mm, and were estimated to mature at c.10 months. Females possessed a type one pouch containing four nipples and carried 2–4 young.

Activity patterns. There is no specific information for this species, but captive studies indicate that the Habbema Dasyure is almost exclusively nocturnal and probably largely ground dwelling.

Movements, Home range and Social organization. One study described spool-and-line tracking of the Habbema Dasyure in montane forest in the Mount Kaindi and Porgera of Papua New Guinea. Four individuals were tracked, one at Porgera and three on Mount Kaindi. Two males were tracked until the line ran out without reaching a nest, and two females were tracked to holes in the ground. These holes led to burrow systems, one of which had two entrances; both had nesting chambers located 80–100 cm below ground level. Nests were made of interwoven leaves and ferns. Both individuals returned to their burrows via indirect routes (one traversing 160 m), traveling for up to 3 m in caverns between moss, roots, and leaf litter. In one study on Mount Kaindi, 32 Habbema Dasyures were released, and eleven were recaptured at least once. Seven were recaptured twice, and two were recaptured three times. All except one were recaptured 10–100 m from points of release; the exception was a male that was recaptured six months later, some 300–400 m away.

Status and Conservation. Classified as Least Concern on The IUCN Red List. The Habbema Dasyure has a wide distribution, and no major conservation threats are known. The Habbema Dasyure occurs at high elevations in New Guinea, where it is not greatly affected by hunting or habitat loss. Montane grasslands are burned periodically, but this is not perceived as too damaging to population numbers.

Bibliography. Armstrong et al. (1998), Flannery (1995a), Grossek et al. (2010), Helgen (2007a, 2007b), Helgen & Opiang (2011), Krajewski, Torunsky et al. (2007), Krajewski, Wroe & Westerman (2000), Krajewski, Young et al. (1997), Laurie (1952), Leary, Seri, Wright et al. (2008c), Lopez (2011), Tate (1947), Van Dyck (2002), Woolley (1984, 1989, 2003), Woolley et al. (1991).

40. Black-tailed Dasyure Murexia melanurus French: Murexie à queue noire / German: Schwarzschwanz-Neuguinea-Beutelmaus / Spanish: Dasiuro de cola negra Other common names: Black-tailed Antechinus, Broad-footed Marsupial Mouse

Taxonomy. Phascogale melanura O. Thomas, 1899, Moroka, 9° 24’ S, 147° 32’ E, 1300 m, Astrolabe Range, Central Prov., Papua New Guinea.

Acceptance of the trans-Torresian distribution of Antechinus prevailed until 1984 when P. A. Woolley’s work on phallic morphology indicated a dubious relationship between Australian and New Guinean members of Antechinus, and thus challenged integrity of Phascogalinae. Antechinus in Australia, meanwhile, were no longer considered monophyletic, including what we now regard as several genera: Dasykaluta rosamondae, Pseudantechinus macdonnellensis, P. ningbing, P. bilarni, and Parantechinus apicalis. This was followed by work clarifying species applicable to “antechinus” of New Guinea (melanurus, habbema, and naso). This research indicated that New Guinean species deserved generic reclassification; their inclusion in Antechinus was evidently inappropriate. DNA hybridization and albumin immunology studies confirmed a closer relationship among New Guinea species than with Australian Antechinus. Subsequent DNA work suggested that New Guinean taxa were sister to Australian antechinuses. Then, in 2002, S. Van Dyck’s rigorous morphological study of Australian and New Guinean “antechinuses” concluded

On following pages: 41. Short-furred Dasyure (Murexia longicaudata); 42. Broad-striped Dasyure (Murexia rothschildi); 43. Long-nosed Dasyure (Murexia naso); 44. Red-tailed Phascogale (Phascogale calura); 45. Northern Brush-tailed Phascogale (Phascogale pirata); 46. Common Brush-tailed Phascogale (Phascogale tapoatafa); 47. Giles’s Planigale (Planigale gilesi); 48. Long-tailed Planigale (Planigale ingrami); 49. Common Planigale (Planigale maculata); 50. Papuan Planigale (Planigale novaeguineae); 51. Narrow-nosed Planigale (Planigale tenuirostris); 52. Wongai Ningaui (Ningaui ridei); 53. Pilbara Ningaui (Ningaui timealeyi); 54. Southern Ningaui (Ningaui yvonneae); 55. Kultarr (Antechinomys laniger).

299

FAMILY DASYURIDAE Carnivorous Marsupials

FAMILY PSEUDOCHEIRIDAE Ring-tailed Possums and Greater Gliders

Home ranges of many species of pseudocheirids are not fully documented. For those that are, the home ranges are small, typically ranging from <1 ha to 4 ha.

The Herbert River Ring-tailed Possum is reported to have home ranges of 0·52–3·3 ha, depending on available resources (den sites and food). The Lemuroid Ringtailed Possum (Hemibelideus lemuroides) has relatively small home range sizes of (0·15–1·7 ha) and the Southern Greater Glider (Petauroides volans) and the Northern Greater Glider (Petauroides minor) have relatively larger home ranges of 0·9–4·4 ha and 0·9–4·2 ha, respectively. Studies conducted on the Southern Greater Glider determined that home range size in this species was influenced by habitat patch size and patch density. As patch size increases and patch density decreases the home range size of the Greater Southern Glider increases.

Pseudochirulus herbertensis Atherton Tableland, Queensland, Australia.

Photo: Jiri Lochman/ Lochman Transparencies

656

0·9–4·2 ha for the Northern Greater Glider, 0·9–4·4 ha for the Southern Greater Gliders, 0·52–3·3 ha for the Herbert River Ring-tailed Possum, 1–2·5 ha for the Western Ring-tailed Possum, 0·64–1 ha to more than 10 ha for the Eastern Ring-tailed Possums, 0·5–1·2 ha for the Rock Ring-tailed Possum, and 1·4– 2·2 ha for the Coppery Ring-tailed Possum.

Studies also suggest that home range size of Southern Greater Gliders increases with increasing patch size and reduced patch density, so small patches of habitat have more individuals per unit area and have smaller home ranges and

greater home range overlap. This suggests a degree of flexibility in their use of space. It also appears that some aspects of social organization of the Southern Greater Glider may change with density. For example, its mating system was proposed to be facultative polygyny in a low-density population (0·56 ind/ ha) in Victoria, Australia, with four males being bigamous and five being monogamous. Another study in Victoria found that males occupied exclusive home ranges and maintained sole access to consort females by an amalgamation of female- and resource-defense. The limited information available to date

The Herbert River Ring-tailed Possum is quite distinct among the ring-tailed possums. Its dark, almost black back and white on the under parts make it easy to identify. Breeding can occur anytime from April–December, but peak breeding time is May–July.

Females usually give birth to 1–2 young per year. The pouch has two teats and young will remain in the pouch for up to 120 days before they permanently emerge.

Within two weeks of emerging from the pouch, young will begin to forage independently from their mother. Weaning occurs at about 150–160 days. Young continue to share their mother’s den and ride on her back for about 35 days after emerging from the pouch. The fur of the young is a light fawn color and gradually changes to the adult color at sexual maturity at about one year of age.

Pseudochirulus herbertensis Julaten, NE Queensland, Australia.

Photo: Hans & Judy Beste/ Lochman Transparencies

FAMILY PSEUDOCHEIRIDAE Ring-tailed Possums and Greater Gliders

Pseudocheirus peregrinus Australia.

Photo: ANT Photolibrary/NHPA

The mating system of the Southern Greater Glider has been reported as monogamous, polygamous, or polygynous, depending on habitat suitability and population density.

Only one offspring is produced annually, and it is assumed that the two other species of Petauroides also produce a single offspring. Length of gestation is unknown. Most young are born in April through May and spend 90–120 days in the pouch after which they are either carried on their mother’s back or left in the nest while she forages alone.

About 90 days after leaving the pouch, the young gradually become independent of their mothers at which point they are 10–11 months old. Detailed information on dispersal is not abundant, but for some individuals, it may involve inheriting parts of their mothers’ home ranges.

Petauroides volans Queensland, Australia.

Photo: Stanley Breeden/DRK

suggests that most species of pseudocheirids have a polygamous mating system.

Generally, densities of pseudocheirids are low and affected by habitat quality and food and nutrient availability. Reported densities include 0·1–4·5 ind/ha for Western Ring-tailed Possums, 1·9–4·8 ind/ha for Lemuroid Ring-tailed Possums, 0·01–5·5 ind/ha for Southern Greater Gliders, 0·55–1·6 ind/ ha for Herbert River River-tailed Possums, and 0·36–1·3 ind/ha for Green Ring-tailed Possums. Highest densities of a species of pseudocheirids have been reported at 4–34 ind/ha for the Eastern Ring-tailed Possum. Highest density of Eastern Ringtailed Possums was observed in a eucalypt plantation with a thick, shrubby understory.

Pseudocheirids are preyed on by a variety of reptilian, avian, and mammalian predators, both native and introduced particularly in Australia. Where information is available, arboreal pythons prey on at least eight species of pseudocheirids.

Boelen’s pythons (Morelia boeleni) prey on the Coopery Ringtailed Possum; amethystine pythons (M. amethistina) prey on Lemuroid Ring-tailed Possums, Daintree River Ring-tailed Possums, and Herbert River Ring-tailed Possums; and carpet pythons (M. spilota) prey on Daintree River Ring-tailed Possums, Herbert River Possums, Western Ring-tailed Possums, and Eastern Ring-tailed Possums. Lace monitors (Varanus varius) are known to eat Eastern Ring-tailed Possums. Given their matching nocturnal activity, owls prey on various species of pseudocheirids. Rufous owls (Ninox rufa) prey on Lemuroid Ring-tailed Possums, Northern Greater Gliders, and Herbert River Ring-tailed Possums. Lesser sooty-owls (Tyto multipunctata) prey on Lemuroid Ring-tailed Possums, Daintree River Ring-tailed Possums, and Herbert River Ring-tailed Possums, and powerful owls (N. strenua) prey on Eastern Ring-tailed Possums and Southern Greater Gliders. A study in an unlogged forest in south-eastern New South Wales recorded a 90% reduction in the population size of the Southern Greater Glider in less than four years as a result of predation by a pair of powerful owls. Mammalian predators of pseudocheirids include the Spotted-tailed Quoll (Dasyurus maculatus)— Australia’s largest marsupial carnivore. It is known to prey on Lemuroid Ring-tailed Possums and Daintree River Ring-tailed Possums. Dingoes (Canis lupus dingo) are also known to capture and eat Daintree River Ring-tailed Possums, perhaps also variable goshawks (Accipiter novaehollandiae). Introduced Red Foxes (Vulpes vulpes) and domestic/ feral cats can be prob-

lematic predators of Western Ring-tailed Possums and Eastern Ring-tailed Possums.

Relationship with Humans Humans have impacted the pseudocheirids in a wide variety of ways. Impacts include loss of habitat through clearing, disturbance, and mortality from traffic, noise pollution, and edge effects, including weed invasion, predation from introduced

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The Eastern Ring-tailed Possum has a reproductive rate of 1·8–2·4 young per year and even though the female’s pouch has four teats they typically give birth to only two young. Rarely is a female seen with four offspring. There are two peak birthing periods between April and December; a major peak in late May through July and a minor peak in mid-October through November. This second peak is the result of females who produce a second litter within the year. Young remain in the pouch about 120 days and then stay close to the mother to nurse for the an additional 2–3 months until they are weaned at about 180 days. Young Eastern Ringtailed possums disperse at about 8–12 months.

1

2

3

creamy-white morph

gray morph

5

variants

rich-red morph

4 variants

6

7

9 8

black morph

11 12 PLATE 30

10

inches cm

8 20

FAMILY PSEUDOCHEIRIDAE Ring-tailed Possums and Greater Gliders

Plate 30 Species Accounts

Subfamily HEMIBELIDEINAE Genus HEMIBELIDEUS

Bibliography. Burnett & Winter (2008a), Flannery (1994), Goudberg (1990), Kanowski et al. (2001), Laurance, S.G. & Laurance (1999), Laurance, W.F. (1990a, 1990b), Laurance, W.F. & Laurance (1996), Laurance, W.F. et al.

(2008), McQuade (1984), Van Dyck & Strahan (2008), Wilson et al. (2007), Winter & Atherton (1984).

Collett, 1884

French: Possum lémurien / German: Lemuren-Ringbeutler / Spanish: Falangero lemuroide Other common names: Lemur-like Ringtail, Lemuroid Ringtail, Lemuroid Ringtail Possum

Taxonomy. Phalangista (Hemibelideus) lemuroides Collett, 1884, “Northern Queensland,” Australia.

This species is monotypic.

Distribution. NE Australia (N Queensland).

Descriptive notes. Head–body 31·3– 40 cm, tail 23–38·4 cm; weight 810–1170 g.

The Lemuroid Ring-tailed Possum looks superficially like greater gliders (Petauroides), but it lacks patagium on each side of its body. Fur is long and woolly and occurs in two color morphs. One is chocolatebrown; the other, a less common color phase, is creamy-white. Creamy-white individuals were previously described as a different species. Both color morphs have yellowish ventral fur and a slightly bushy tail that is only slightly tapered.

Habitat. Remnant primary rainforest linked to large tracts of continuous forest.

Food and Feeding. Lemuroid Ring-tailed Possums are known to feed on leaves of at least 37 species of rainforest trees of the families Lauraceae, Elaeocarpaceae, and Rutaceae. These include the Queensland maple (Flindersia brayleyana); buff walnut (Endiandra sideroxylon); white carabeen (Sloanea langii); brown quandong (Elaeocarpus eumundi); brown tamarind (Castanospora alphandii, Sapindaceae); walnut (Endiandra sp.); bollywood (Litsea leefeana); dogwood (Ceratopetalum succirubrum, Cunoniaceae); maple silkwood (Flindersia pimenteliana); Lamington’s silky oak (Helicia lamingtoniana, Proteaceae); blush walnut (Beilschmiedia obtusifolia); bumpy satinash (Syzygium cormiflorum, Myrtaceae); Euodia sp.; ivory walnut (Cryptocarya angulata, Lauraceae); white ash (Alphitonia petriei) and red ash (Alphitonia whitei, both Rhamnaceae; and eungella satinash (Acmena resa, Myrtaceae). Lemuroid Ring-tailed Possums also feed on flowers of bollywood and fleshy outer coverings of fruit of yellow walnut (Beilschmiedia bancroftii, Lauraceae).

Breeding. Pouch of the Lemuroid Ring-tailed Possum contains two teats. One young is produced at a time. Most births occur in August–November, and young are seen riding on their mothers’ backs in October–April.

Activity patterns. Lemuroid Ring-tailed Possums are nocturnal and emerge from their nests just after dark and may not return until dawn is breaking. During the night, they most commonly forage at heights of 11–20 m and make glider-like long leaps of 2–3 m between trees. They are strictly arboreal and are found higher in the canopy than sympatric folivorous ring-tailed possums of similar mass such as the Green and the Herbert River ring-tailed possums. During the day, Lemuroid Ring-tailed Possums use tree hollows and do not construct nests.

Movements, Home range and Social organization. The Lemuroid Ring-tailed Possum is more gregarious than most other pseudocheirids; groups of 2–3 individuals are often seen feeding together and sharing a tree hollow nest. Groups of up to eight individuals have been observed. These groups probably consist of an adult male and female and subadults or young-at-foot (that have left the pouch but are not yet weaned).

Home ranges of 0·15–1·7 ha are aligned with forest edge. Mean density of the Lemuroid Ring-tailed Possum is 1·9 ind/ha, with a maximum of 4·8 ind/ha. Adults are not known to vocalize to any extent, although juveniles produce a high-pitched hissing squeak when separated from their mothers. Both sexes have a strong musky odor and drag their cloaca along branches, which suggests olfaction is important in communication. Predators of the Lemuroid Ring-tailed Possum include amethystine pythons (Morelia amethistina), rufous owls (Ninox rufa), lesser sooty-owls (Tyto multipunctata), and Spotted-tailed Quolls (Dasyurus maculatus).

Status and Conservation. Classified as Near Threatened on The IUCN Red List. The Lemuroid Ring-tailed Possum occurs in rainforests of northern Queensland in two distinct localities: one population occurs above 450 m in elevation between Ingham and Cairns, and the other, a smaller population, above 1100 m on the Mount Carbine Tableland, west of Mossman. Lemuroid Ring-tailed Possums are very vulnerable to habitat fragmentation because they do not come to the ground to transfer between patches of habitat. One study found that a population declined by more than 99% in forest fragments and secondary regrowth after clearing. The relative inability of Lemuroid Ring-tailed Possums to use corridors means they require large areas of intact primary rainforest and corridors of primary rainforest of at least 200 m in width. They exhibit a suite of traits that makes them particularly vulnerable to forest fragmentation, including being strictly arboreal, feeding almost entirely on the leaves of primary forest trees, and requiring a hollow tree-cavity for daytime denning. Although the area of rainforest available to the Lemuroid Ring-tailed Possum has declined as a result of clearing and fragmentation, its total population is thought to be stable.

Genus PETAUROIDES O. Thomas, 1888

2. Central Greater Glider Petauroides armillatus French: Possum de Lumholtz / German: Mittlerer Großflugbeutler / Spanish: Falangero planeador central

Taxonomy. Petauroides volans armillatus O. Thomas, 1923, “Coomooboolaroo, 80 miles S.W. Rockhampton,” Queensland, Australia.

Until recently, this species was considered a synonym of P. volans and, more specifically, of its northern subspecies minor.

Monotypic.

Distribution. NE Australia in mid-Queensland, from just N of Townsville, S to the Eungella Range and the vicinity of Roma.

Descriptive notes. Head–body 30–42 cm, tail 40–53 cm; weight 750–1200 g. The Central Greater Glider is intermediate in size between the Northern Greater Glider (P. minor) and the Southern Greater Glider (P. volans). It differs from the Northern Greater Glider in having larger ears, pale post-auricular patch, distinctly darker gray-brown mid-dorsal zone on body that contrasts with pale gray flanks, darker crown but no dorsal head stripe, patch of pale gray fur patch that extends c.20% along undersurface of tail from its base, and dark fur on lower one-half of forelimbs and hindlimbs. Similar to other greater gliders, the Central Greater Glider has a gliding membrane that extends from its elbow to ankle on each side of the abdomen.

Habitat. Open forests dominated by Eucalyptus trees.

Food and Feeding. There is no specific information available for this species, but diets of the Central Greater Glider are presumably similar to those of the Northern Greater Glider and the Southern Greater Glider.

Breeding. There is no specific information available for this species, but breeding activities are presumably similar to those of the Northern Greater Glider and the Southern Greater Glider.

Activity patterns. There is no specific information available for this species, but activity patterns are presumably similar to those of the Northern Greater Gliders and the Southern Greater Glider.

Movements, Home range and Social organization. There is no specific information available for this species, but movements, home range, and social organization are presumably similar to those of the Northern Greater Glider and the Southern Greater Glider.

Status and Conservation. The Central Greater Glider has not been assessed for The IUCN Red List. Given its recent recognition as a species, its conservation status is unknown.

Bibliography. Arbogast et al. (2011).

3. Northern Greater Glider Petauroides minor French: Possum mineur / German: Nördlicher Großflugbeutler / Spanish: Falangero planeador septentrional

Taxonomy. Petaurista volans var. minor Collett, 1887, type locality not given. Restricted by O. Thomas in 1923 to “Herbert Vale, North Queensland [Australia].”

Until recently, this species was considered a subspecies of P. volans. Monotypic.

Distribution. NE Australia in NE Queensland, from just N of Cairns (Windsor Tableland) S to Townsville.

Descriptive notes. Head–body 30–40 cm, tail 40–48 cm; weight 700–900 g. The Northern Greater Glider is smaller than all southern species of pseudocheirids. It differs from the Southern Greater Glider (P. volans) in having a more slender body with shorter ears that lack a post-auricular pale spot, and fur on back and flanks is more evenly hued. Distinct mid-dorsal stripe is usually present on head and tail. Unlike the two other species of greater gliders in Queensland, only hands and feet of the Northern Greater Glider are dark-furred, and pale gray fur below is restricted to base of tail.

Similar to other greater gliders, the Northern Greater Glider has a gliding membrane that extends from its elbow to ankle on each side of the abdomen.

Habitat. Tropical sclerophyll forest.

On following pages: 4. Southern Greater Glider (Petauroides volans); 5. Lowland Ring-tailed Possum (Pseudochirulus canescens); 6. Weyland Ring-tailed Possum (Pseudochirulus caroli); 7. Daintree River Ring-tailed Possum (Pseudochirulus cinereus); 8. Painted Ring-tailed Possum (Pseudochirulus forbesi); 9. Herbert River Ring-tailed Possum (Pseudochirulus herbertensis); 10. Masked Ring-tailed Possum (Pseudochirulus larvatus); 11. Pygmy Ringtailed Possum (Pseudochirulus mayeri); 12. Arfak Ring-tailed Possum (Pseudochirulus schlegeli).

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1. Lemuroid Ring-tailed Possum Hemibelideus lemuroides

FAMILY ACROBATIDAE Feather-tailed Gliders and Feather-tailed Possum

Feather-tailed gliders make frequent short glides of 10–15 m, and occasionally up to 28 m. These are impressive distances for animals with a head–body length of just 5–7 cm, plus a slightly longer tail, and with a typical weight of 8–12 g. Individuals from Northern Australia, where only the Broad-toed Feather-tailed Glider occurs, are slightly smaller. Captive and photographic studies have shown that feather-tailed gliders prepare themselves for launching by gathering their flexed limbs under their bodies, before pushing off vigorously with both hindlimbs simultaneously.

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Acrobates frontalis Australia.

Photo: ANT/NHPA

sent in the Honey Possum); the alisphenoid contribution to the antero-medial margin of the glenoid fossa (unique within Diprotodontia but widespread in other orders of marsupials); the extreme elongation of the stapedial footplate (matched in the Honey Possum); the fusion of the malleus and incus, reduction of the malleolar lamina and neck, and elongation of the posterior incudal process (duplicated in the Honey Possum); the unusually elongate incisive foramina (matched in the Honey Possum and the Mountain Pygmy Possum, Burramys parvus, Burramyidae); the greatly enlarged posterior palatal vacuities that are united across the midline (almost as large in burramyids, although always separated by a medial bony strut); the presence of large lacrimal and palatine laminae and broad contact between these elements in the medial orbital wall (also in species of Cercartetus, some potoroids, and many dasyurids, peramelids, and didelphoids); and the presence of a very large interparietal element that is in broad bilateral contact with the mastoid region of each petrosal (a similar condition is present in the Honey Possum).

The suite of middle-ear anatomical features in acrobatids all point toward enhanced low frequency perception, perhaps as an adaptation to listen for wing-beat of owls, their likely major predators. In this context, the unique osseous disc in the outer ear canal has been interpreted as a “low-pass” filter that might reduce the transmission of unwanted higher frequency sounds through to the tympanic membrane and thence to the ossicular chain. One potential issue with this model is that young feather-tailed gliders have been reported to emit high-pitched squeaks that could potentially be inaudible to the parents.

These and other issues related to hearing in acrobatids require further attention.

Feather-tailed gliders differ cranially from the Feather-tailed Possum in having a proportionally larger and more inflated neurocranium, a proportionally shorter and deeper rostrum, and a vertically expanded sphenorbital fissure. These features might be regarded as expressions of paedomorphism associated with evolutionary reduction in body size.

The acrobatid postcranial skeleton shows few overt specializations in either genus compared with other small non-volant possums such as burramyids. As noted above, the limb elements

of both species of feather-tailed gliders are not noticeably elongated as they are in the other genera of gliding marsupials.

The principal tarsal bones of acrobatids are not greatly modified from the reconstructed ancestral morphotype for all Australian marsupials. This is true also of the other smallerbodied possums in the Burramyidae and Petauridae. Important aspects of this morphology are the “continuous lower ankle joint pattern” with its broad, saddle-shaped calcaneo-astragalar facet, and a prominent lateral calcaneal flange. The tuber calcis is relatively short in feather-tailed gliders and longer in the Feather-tailed Possum, but otherwise there are few observable differences in these elements.

One of the only observations on the brain of an acrobatid is the unlikely claim that feather-tailed gliders lack the fasciculus aberrans seen in all other diprotodontians and instead have a true corpus callosum connecting the hemispheres like placental mammals. This requires confirmation.

The epidermal covering of the bony palate in acrobatids features a prominent incisive papilla, bounded laterally by slit like apertures of the naso-palatine ducts, a series of seven transverse palatal rugae (ridges) of which the third is the most strongly curved, and a posterior torus that delimits the hard from the soft palate. A feature uniquely shared by acrobatids and other diprotodontians is the presence of a row of small anterior-facing triangular papillae on the anterior face of the posterior palatal ruga. Heavy secondary ornamentation is present between the anterior ruga, as in the majority of diprotodontians. The anterior palatal ruga in acrobatids lack an apical groove of the kind found in the first two or three rugae in petaurids, pseudocheirids, and phalangerids.

The tongue of acrobatids is elongate and highly protrusible.

The anterior portion of the tongue bears the usual range of papillar types, including the compound filliform (or coronate) type that is characteristic of marsupials and the rounded fungiform type. At the lingual apex, fine hair-like papillae predominate, creating a distinct “brush.” These give way posteriorly to more typical compound filliform papillae. Other features of special note are the smooth mucosal surface surrounding the vallate papillae at the rear of the tongue, the disproportionately large size of the posterior vallate papillae (especially in

FAMILY ACROBATIDAE Feather-tailed Gliders and Feather-tailed Possum

The absence of a cream margin on the fringe of the tail of this individual suggests that it is a Broad-toed Feather-tailed Glider. The forelegs and hindlegs, both of which are slightly raised during gliding, are being lowered and extended in preparation for landing on the vertical trunk of a tree. The patagium (gliding membrane) of both species of feather-tailed gliders extends from the elbow to the knee. Unlike other species of gliding marsupials, feather-tailed gliders do not have elongated limb bones, and the patagium is relatively small in area. A fringe of longer hairs increases its effective surface area. During steady gliding, the forelimbs of feather-tailed gliders are held “elbows-out,” as in the greater gliders (Petauroides and Pseudocheiridae), but unlike the “hands-out” mode of the “wristwinged” Petaurus gliders, such as the Sugar Glider (P. breviceps).

Longer glides may reach speeds of 5·3–7·5 m/s. Feather-tailed gliders steer primarily by adjusting their limb positions, but the feather-like tail is used during long glides to generate pitching movements, and for minor adjustments of the angle of attack and glide angle.

717

Acrobates frontalis Australia.

Photo: ANT/NHPA