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1 Running Head: PLATYPUS The Platypus: Ornithorhynchus anatinus Erin Blanchard Algonquin College Course: 14F_ADN7142_010: Wildlife for Naturalists Instructor: Kristi Beatty Due: Tuesday November 18th, 2014

2 Table of Contents Introduction: The Platypus: Ornithorhynchus anatinus... 3 Discovery and History... 3 Classification... 3 Main Report: The Life of the Duck-Billed Platypus... 4 Identification... 4 Distribution and Habitat... 5 Feeding Habits... 6 Life Cycle, Reproductive Habits, and Communication... 7 Predators, Parasites, and Diseases... 8 Species Status and Human Impact... 9 Conclusions: What s Next for the Duck-Billed Platypus?... 9 References Appendix A Appendix B Appendix C Appendix D Appendix E Appendix F

3 The Platypus: Ornithorhynchus anatinus Discovery and History The platypus, also commonly referred to as the duck-billed platypus, is a puzzling creature to many scientists and laypersons alike due to its odd conglomeration of characteristics. The platypus has duck-like traits - its bill and webbed-feet, beaver-like traits - its tail, and otter-like traits - its brown, waterproof fur and general body shape (Australian Museum, 2014). When scientists first discovered the platypus they believed it to be an embellished joke (National Geographic Society, 2014). George Shaw, an English naturalist, was the first person to publish a scientific description of the platypus in his works The Naturalist s Miscellany, 1799 (Calaby, 1967). For a visual representation of the platypus please refer to Appendices A through C. Classification The table below outlines the complete taxonomic classification of the platypus. Kingdom Animalia Phylum Subphylum Class Subclass Order Family Genus Chordata Vertebrata Mammalia Prototheria Monotremata Ornithorhynchidae Ornithorphynchus Species anatinus Table 1. The Taxonomic Classification of the Platypus. (Australian Museum, 2014). The platypus is a unique mammal classified as a monotreme (order Monotremata) meaning it lays yolked eggs and has a single opening for both the urogenital and digestive 3

4 systems (Australian Wildlife, n.d.). The only other living monotremes are the echidnas (longbeaked and short-beaked) of Australia and New Guinea. Identification Main Report: The Life of the Duck-Billed Platypus As previously stated, the duck-billed platypus can be identified by its duck-like leathery bill and webbed feet; broad, flat, beaver-like tail; and streamline, otter-like body shape and fur (Australian Museum, 2014). More specifically, its front feet are fully-webbed and used for paddling whereas its hind feet are partially-webbed and used as rudders (Australian Museum, 2014); all its feet are five-toed and clawed (Canadian Museum of Nature, 2013; Australian Museum, 2014). There are several other characteristics unique to the platypus that help in its identification including its size and other visible traits. The male platypus is larger than the female platypus; males are generally 40-63cm long from bill-tip to tail-tip (Australian Museum, 2014) and have been known to reach 65cm in length (Canadian Museum of Nature, 2013), whereas the smaller female is typically 37-55cm long (Australian Museum, 2014). The tail comprises 12-15cm of a platypus total length (Canadian Museum of Nature, 2013). According to the Australian Museum (2014) males can weigh kg and females can weigh kg. In addition to size and weight, every male carries a venomous spur, 1.5cm long, on each of its hind ankles; these horny spurs are used in the defence against predators and to battle other males for female mates (Natural History Collections, n.d.; See appendix D for an example). Every platypus is born with hind spurs, however, the females lose their spurs within a year of hatching because they serve no purpose (Natural History Collections, n.d.). The spurs and their venom can inflict nasty wounds, killing animals the size of a large dog and causing severe pain in humans for up to several weeks (Australian Wildlife, n.d.). The platypus is one of only a few venomous mammals (Australian Museum, 2014); for more information on its 4

5 evolution of venomous abilities please refer to Whittington et al (2008) in the reference section. Unfortunately, you can rule out seeing a platypus in Canada and even the rest of North America and South America. In fact, the platypus in only found on one continent in the entire world - Australia. Distribution and Habitat The duck-billed platypus is endemic to Australia, meaning Australia is the only place that the platypus is found in its natal habitat (Australia Museum, 2014). The platypus inhabits the eastern coast of Australia including eastern Queensland, New South Wales, eastern, central, and south-western Victoria, Tasmania, and King Island (Lunney et al., 2008, para. 1). The platypus is also found on Kangaroo Island where it was recently introduced (Carrick et al. 2008, as cited in Lunney et al., 2008, para. 1) and is extant from the Adelaide Hills and Mount Lofty Ranges of South Australia. The Western limits of its range are poorly known (Australian Museum, 2014). Please refer to Appendix E for a map displaying the platypus range in Australia. Platypus introductions to the western coast of Australia failed (Australian Museum, 2014) due to the lack of wet habitat on this side of the continent. The platypus is not found in other parts of the world because it is geographically separated from all other continents, not because its habitat is only found in Australia. The platypus depends on fresh water in the form of streams, rivers, and other large bodies such as lakes, reservoirs, and farm dams (Australian Museum, 2014; Australian Wildlife, n.d.). More specifically, it requires slow-moving pools that are 1-2m deep and flush with aquatic vegetation and benthic vertebrates (Lunney et al., 2008). Furthermore, the steep, angled banks must consist of firm soil to ensure the platypus can dig its shallow and rudimentary burrow as well as more intricate nests (Natural History Collections, n.d.; Australian Wildlife, n.d.). The platypus has specially designed feet; the foot webbing that helps a platypus swim retracts when it climbs onto land, revealing a set of strong claws that aid in running and building dirt burrows at 5

6 the water s edge (National Geographic Society, 2014; Australian Museum, 2014). The platypus fur layers - a waterproof outer layer of guard hairs and an insulating inner layer of fine hairs - act as a thermal insulation blanket, allowing it to live in cold alpine waters as well a warm tropical waters (Natural history collections, n.d.). Furthermore, the platypus is an endothermic mammal that creates its own internal heat (32ºC), an adaption that enables it to survive in colder waters (Australian Wildlife, n.d.). Based on these observations, the platypus must also have adaptations that allow it to feed on the smaller organisms that thrive in colder, fresh water. Feeding Habits The platypus is a carnivorous mammal who performs all of its hunting underwater (National Geographic Society, 2014). Its diet consists mainly of larvae, insects, shellfish, worms, and small fresh water shrimp (National Geographic, 2014; Australian Wildlife, n.d.). The platypus is a bottom-feeder who dives for food, using its front feet to paddle, its hind feet and tail to steer. The sensitive electroreceptor pores in its bill are used to detect the muscle movements of small invertebrates living in the mud of the stream bed (Scheich, E., Langer, G., Tidemann, C., Coles, R. B., & Guppy, A., 1986; National Geographic Society, 2014; Canadian Museum of Nature, 2013). As the platypus disturbs the mud, its electrosensitive bill senses the prey s movement; the platypus scoops up its prey as well as some of the stream bed s gravel and mud (Natural History Collections, n.d.). After 1-2 minutes of submersion or when its specialty cheek pouches are full, the platypus returns to the surface. Here, the platypus proceeds to crush and consume its prey, with the help of its horny buccal pads (in lieu of teeth) and some of the gravel it collected (National Geographic Society, 2014; Natural History Collections, n.d.). When a platypus hunts folds of skin cover [its] eyes and ears to prevent water from entering, and the nostrils close with a watertight seal (National Geographic Society, 2014, para. 2). Therefore, the platypus can hunt in murky waters and without light (Canadian Museum of Nature, 2013). It is known that the platypus is an active hunter during twilight (crepuscular) and 6

7 night time (nocturnal; National Geographic Society, 2014). The platypus can remain in waters of 0ºC for up to 12 hours (Natural History Collections, n.d.) - the amount of time it needs to spend foraging every day in order to consume enough calories (Australian Wildlife, n.d.). Extra calories are stored in the platypus tail as fat (Australian Museum, 2014). Life Cycle, Reproductive Habits, and Communication According to Lunney et al. (2008) platypus can live for up to 20 years in the wild where both male and female platypus become sexually mature at the age of two years (Australian Platypus Conservancy, 2014). The breeding season occurs during late winter to early spring (Australian Wildlife, n.d.) and mating rituals have been observed strictly in the water (Australian Platypus Conservancy, n.d.). During this time the female platypus digs a separate breeding burrow from the main burrow. She will seal herself inside for 3-4 months until her offspring hatch and become mature enough to swim on their own (National Geographic Society, 2014; Natural History Collections, n.d.). If the mother must leave the breeding burrow for a short period of time she will seal in her offspring (Australian Wildlife, n.d.). In her breeding burrow the female will lay 1-3 eggs every year (Carrick et al. 2008, as cited in Lunney et al., 2008, para. 3); she will incubate them between her tail and body for up to 10 days before they hatch. The blind and hairless hatchlings are the size of a lima bean (National Geographic Society, 2014; Australian Wildlife, n.d.). The platypus offspring feed on their mother s milk through openings in her skin (no nipples) placed above the mammary glands (Canadian Museum of Nature, 2013). The male platypus does not help raise his offspring (Australian Wildlife, n.d.). This information is surprising due to the fact that mammals who have few offspring, once a year, who require a lot of care, usually show high levels of parental investment wherein both parents help raise their young. Aside from the long-beaked and short-beaked echidnas, the platypus is the only other mammal that lays eggs (National Geographic Society, 2014). 7

8 The platypus is mainly a solitary animal; females and their young forage in separate ranges from each other and males are typically only seen together when fighting for territory or a mate in the early spring season (Australian Platypus Conservancy, n.d.). During the breeding season males have been known to produce a musky odour as well as a yellow territory-marking liquid (Australian Platypus Conservancy, n.d.). When platypus mate they perform a kind of dance in the water; it begins when either the male or female platypus initiates a courtship (Australian Platypus Conservancy, n.d.). The sequence starts by touching bills for upwards of 10 minutes, then brushing against each other, and ending when the male attaches to the female s tail with his bill, following her as she swims in circles before copulation begins (Australian Platypus Conservancy, n.d.). When platypus are annoyed or threatened they may procure a growl. Predators, Parasites, and Diseases Native predators of the platypus may include crocodiles, goannas, carpet pythons, eagles, large native fish, and even dingos when the platypus ventures onto land (Australian Museum, 2014). Lunney et al. (2008) reported that the invasive and introduced fox species is also a predator of the platypus and has negatively affected the Tasmania population. The only known parasite to effect the platypus is its own unique tick species, Ixodes ornithothynchi, that is found around its legs (particularly its hind legs) and in its fur (Australian Museum, 2014; Australian Platypus Conservancy, n.d.). Lastly, there is an amphibian fungal infection, Mucor amphibiorum, circulating throughout the Tasmanian population of platypus that causes skin ulcers and in certain cases can be fatal if it infects the animal s lungs (Australian Museum, 2014). It s negative effects have declined four-fold from 1990 to and it has never been reported in the mainland populations (Australian Platypus Conservancy, n.d.). 8

9 Species Status and Human Impact The International Union for Conservation of Nature (IUCN) gave the platypus a status of Least Concern (Lunney et al., 2008). The platypus holds this status because it has a wide distribution, a presumed large population, and there is no evidence to suggest that its numbers will rapidly decline at a pace that is necessary to qualify it as Threatened (Lunney et al., 2008). The greatest change in platypus populations have been recorded in the southern parts of Australia. For example, the platypus populations in the Adelaide Hills and Mount Lofty ranges are extinct, as mentioned earlier (Lunney et al., 2008). This is the only known area that platypus have disappeared from since the settlement of european peoples (Australian Wildlife, n.d). Platypus populations are negatively affected by habitat loss and modification, water pollution, and accidental capture (Australian Wildlife, n.d). Platypus are losing their habitat due to reduced water flow in streams and rivers from natural droughts, stream regulation, and the extraction of water for agricultural, domestic, and industrial uses (Lunney et al., 2008). The agricultural and forestry industries as well as urbanization have negatively modified the platypus habitat through bank erosion and stream sedimentation. Poor water quality is a major concern for platypus who live in and around urban areas where suspended solids and heavy metal sediments accumulate (Lunney et al., 2008). Lastly, platypus are prone to getting trapped in fishing and shrimp nets causing accidental drowning (Lunney et al., 2008; Australian Platypus Conservancy, n.d.; Please see Appendix F for an example). Conclusions: What s Next for the Duck-Billed Platypus? More research and observations are needed in order to determine the course of the platypus s survival. From the current research it is evident that their numbers are declining in more urbanized areas where threats to their survival are more abundant. That being said, the platypus range is still very large. It would be beneficial to know the current extent of the entire 9

10 species range, as well as total species numbers, in order to determine their future survival and possible rehabilitation projects. Captive breeding of the platypus has had little success in the past. 10

11 References Australian Museum. (2014). Animal species: Platypus. [Website]. Retrieved from australianmuseum.net.au/platypus/ Australian Platypus Conservancy. (n.d.). Matters of life and death. [Website]. Retrieved from Australian Wildlife. (n.d.). Platypus information. [Website]. Retrieved from wildlife.com/platypus-information.html Calaby, J. H. (1967). Shaw, George ( ). Australian Dictionary of Biography, 2 [Website]. Retrieved from Canadian Museum of Nature. (2013). Mammals: Duck-billed platypus. [Website]. Retrieved from Grant, T. (2013). Platypus. (4th ed.). [Website]. Retrieved from hl=en&lr=&id=kplqn527qzuc&oi=fnd&pg=pp1&dq=platypus&ots=nkg1zilgrj&sig=kmyxz172x owbo5s7aug8iwcsoje#v=onepage&q=platypus&f=false Lunney, D., Dickman, C., Copley, P., Grant, T., Munks, S., Carrick, F., Serena, M., & Ellis, M. (2008). Ornithorhynchus anatinus: The IUCN red list of threatened species. [Website]. Retrieved from National Geographic Society. (2014). Platypus: Ornithorhynchus anatinus. [Website]. Retrieved from Natural History Collections. (n.d.). The platypus. [Website]. Retrieved from Scheich, E., Langer, G., Tidemann, C., Coles, R. B., & Guppy, A. (1986, January 30th). Electroreception and electrolocation in platypus. Nature, 319. [Website]. Retrieved from Whittington, C. M., Papenfuss, A. T., Bansal, P., et al. (2008). Defensins and the convergent evolution of platypus and reptile venom genes. Genome Research,18. [Website]. Retrieved from 11

12 Swimming Platypus Appendix A (Australian Wildlife, n.d.) (Canadian Museum of Nature, 2013). 12

13 (Canadian Museum of Nature, 2013). 13

14 Platypus on Land Appendix B (National Geographic Society, 2014). 14

15 Anatomy of the Platypus Appendix C (Grant & Fanning, 2013). (Grant & Fanning, 2013). 15

16 Male Platypus Venomous Spur Appendix D (Australian Platypus Conservancy, n.d.) 16

17 Platypus Distribution Appendix E (Lunney et al., 2008) 17

18 Dead Platypus from Fishing Line Appendix F (Australian Platypus Conservancy, n.d.) 18