Ornithorhynchus anatinus (Shaw, 1799)

Russell A. Mittermeier & Don E. Wilson, 2015, Ornithorhynchidae, Handbook of the Mammals of the World – Volume 5 Monotremes and Marsupials, Barcelona: Lynx Edicions, pp. 66-67 : 67

Platypus

Ornithorhynchus anatinus

French: Ornithorynque / German: Schnabeltier / Spanish: Ornitorrinco

Other common names: Duck-billed Platypus

Taxonomy. Platypus anatinus Shaw, 1799 ,

“ In Australasia .”

The type locality of P. anatinus is often given as “Australia, New South Wales, New Holland (= Sydney),” which did not appear in Shaw’s original publication, and seems to be a subsequent amalgamation of information from various sources. Following the witnessing by Governor J. Hunter of a Platypus being speared by aboriginal people in a freshwater lagoon around 60 km north-west of the penal colony ofPort Jackson (now Sydney) in 1797, a number of specimens ofthis strange small furred and amphibious animal were transported to England and to Europe. In 1799, one of these specimens (now the type specimen held in the Natural History Museum in London) was described by G. Shaw and named Platypus anatinus. The German anatomist J. F. Blumenbach independently described another specimen, which in 1800 he named Ornithorhynchus paradoxus. The name Platypus had already been given to a genus of beetles, so Blumenbach’s Ornithorhynchus was accepted as the genus but anatinus was deemed to have priority over paradoxusas the species name. Monotypic.

Distribution. E Australian mainland, including the states of Victoria, New South Wales, the Australian Capital Territory, and Queensland (N up to near Cooktown), Tasmania, and King I. Introduced into W Kangaroo I.

Descriptive notes. Head-body 40-63 cm (males) and 37-55 cm (females); weight 0.8-3 kg (males) and 0.6-1.7 kg (females). The Platypus is sexually dimorphic, with males ¢.25% larger than females. There is a clinal increase in body size from north to south, with Tasmanian populations exhibiting larger body size and weight. Some populations also exhibit size variations, apparently not related to latitudinal distribution. For example, individuals from rivers flowing inland from the Great Dividing Range in New South Wales and Victoria are often larger than those found in streams flowing toward the coast in these states. The Platypus has dense, waterproof, and insulating pelage, dark brown to reddish-brown above and pale brown to silvery-cream ventrally. It has a streamlined body shape and distinctive bill. Eyes and ear openings are in single grooves on each side of head. Limbs are short, forefeet are webbed and have broad nails, and hindfeet are partially webbed with sharp claws. Males have a spur of c.1-5 cm in length on ankle region of both hindlimbs. Tail is broad, flat, and sparsely furred, with coarser hairs than body pelage.

Habitat. Permanent freshwater streams and shallow lakes, isolated pools in ephemeral streams, water storage lakes, weir pools, other artificial ponds, and freshwater wetlands and their adjacent riparian zones from tropical rainforest lowlands to the high elevations of Tasmania and the Australian Alps. Platypuses occasionally occur in upper brackish reaches of estuaries.

Food and Feeding. Small benthic macroinvertebrate species are predominant food sources ofPlatypuses. Trichoptera, Ephemeroptera, Odonata, and Plecoptera are the dominant insect groups consumed, but adults of free-swimming species such as small freshwater crustaceans or hemipterans and occasionally tadpoles or small fish are also taken.

Breeding. Platypuses are seasonal breeders, and pre-copulatory behavior, mating, and nest building occur in late winter to early spring. Normal number of eggs is two (1-3), and eggs measure c.14 x 17 mm. Females construct nesting burrows that are used to incubate and nurse their young. Gestation is c.21 days, and incubation ofeggs last c.10 days. Lactation lasts c.4 months, with juveniles emerging from nesting burrows in late summer. Breeding is earlier in the north and later in the south. Both sexes are capable of breeding in second season after independence, but many begin breeding later and not all females breed each year. Platypuses are long-lived, surviving 7-14 years (but up to 21 years) in captivity and in the wild.

Activity patterns. Foraging activity of Platypuses consists of multiple short dives and is predominantly nocturnal. Most individuals seek shelter in burrows during the day, emerging in the late afternoon and reentering burrows in the early morning. The extent of diurnal foraging can vary within and between populations and with the seasons.

Movements, Home range and Social organization. Home ranges of Platypuses are predominantly linear and extend from hundreds of meters to several kilometers. Males appear to have larger and more exclusive home ranges than females. The social system of Platypuses is largely unknown.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Platypuses were historically found in the mountain ranges north and south ofthe city of Adelaide in South Australia but apart from their presence in a small intrusion ofthe Glenelg River across the Victorian border, are represented in this state only by a population introduced between 1929 and 1946 on the western end of Kangaroo Island. There is no evidence that the Platypus ever occurred naturally in Western Australia, and several limited introduction attempts appear to have been unsuccessful. The Platypus is a commonspecies over most ofits distribution, except in the state of South Australia where it is considered endangered. Its dependence on persistent water bodies makes it vulnerable to adverse impacts of water extraction, agriculture, mining, and urbanization. Platypuses are caught and drownedin fishing gear, traps, and nets, used legally and illegally to capture freshwater fish and crayfish. Mortality also occurs as a result of entanglement in rubbish, road kill, and attack by exotic Red Foxes (Vulpes vulpes) and domestic and feral dogs. A recent review recommended that the Platypus be given the status of near threatened under Australian law, due to declines in some local populations, especially in the state of Victoria. Such declines are likely to be exacerbated byclimate change.

Bibliography. Abbott (2008), Bethge (2002), Bethge et al. (2003, 2009), Blumenbach (1800), Bohringer & Rowe (1977), Carrick et al. (2008), De-La-Warr & Serena (1999), Evans et al. (1994), Faragheret al. (1979), Fleay (1980), Furlan (2012), Furlan, Griffiths, Gust, Armistead et al. (2011), Furlan, Griffiths, Gust, Handasyde et al. (2013), Fur lan, Umina et al. (2010), Gardner & Serena (1995), Gongora et al. (2012), Grant (1982, 1983, 2004a, 2004b, 2007), Grant & Dawson (1978a, 1978b), Grant & Temple-Smith (2003), Grant et al. (2004), Griffiths (1978), Grigg etal. (1992), Grus et al. (2007), Gust & Handasyde (1995), Hamilton-Smith (1968), Hawkins & Battaglia (2009), Holland & Jackson (2002), Hulbert & Grant (1983), Klamt et al. (2011), Kolomyjec (2010), Kolomyjec et al. (2009), Long et al. (2002), Lunney, Dickman et al. (2008), Macgillivray (1827), Mahoney (1988), McLachlan-Troup et al. (2010), Munks et al. (2004), Otley et al. (2000), Pettigrew et al. (1998), Pian et al. (2013), Proske & Gregory (2003, 2004), Robinson (1954), Serena & Williams (1998, 2010, 2012), Serena et al. (1998), Scheich et al. (1986), Shaw (1799), Temple-Smith (1973), Temple-Smith & Grant (2002), Thomas (1923b), Troughton (1965a), Whittington, C.M. et al. (2008), Whittington, R.J. & Grant (1984), Williams et al. (2012), Woinarski et al. (2014b).

Figures

Platypus

Distribution. E Australian mainland, including the states of Victoria, New South Wales, the Australian Capital Territory, and Queensland (N up to near Cooktown), Tasmania, and King I. Introduced into W Kangaroo I.