Factors contributing directly to platypus (Ornithorhynchus anatinus) mortality and implications for conserving populations in the wild

Melody Serena; Geoff A. Williams; Jessica L. Thomas

doi:10.1071/AM24032

RESEARCH ARTICLE (Open Access)

Next Contents Vol 47(1)

Factors contributing directly to platypus (Ornithorhynchus anatinus) mortality and implications for conserving populations in the wild

Melody Serena ^A ^* , Geoff A. Williams ^A and Jessica L. Thomas ^B

+ Author Affiliations

- Author Affiliations

^A Australian Platypus Conservancy, PO Box 115, Campbells Creek, Vic 3451, Australia.

^B Healesville Sanctuary, Badger Creek Road, Healesville, Vic 3777, Australia.

^* Correspondence to: platypus.apc@westnet.com.au

Handling Editor: Ross Goldingay

Australian Mammalogy 47, AM24032 https://doi.org/10.1071/AM24032

Submitted: 9 September 2024 Accepted: 30 November 2024 Published: 2 January 2025

© 2025 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the Australian Mammal Society. This is an open access article distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND)

Abstract

Based on details of more than 400 platypus deaths with an identifiable cause recorded since 1989, five main factors contributed directly to platypus mortalities: drowning in fish nets or enclosed crustacean traps (such as opera house traps), being killed by predators (especially canids), becoming accidentally hooked by recreational anglers who then cut the line, becoming entangled in discarded fishing line or other types of litter and being hit by motor vehicles (especially, though not exclusively, in Tasmania). Additional mortality factors included drought, severe flooding, being drawn into irrigation pumps and entrapment in manmade materials or infrastructure. Disease was implicated as being the likely causal agent in two platypus deaths, including a female that died late in lactation. Platypus mortalities were recorded throughout the year on the southeastern Australian mainland but peaked in early autumn, when many recently weaned juveniles are likely to be present. Given the very high number of platypus mortalities attributed to the use of fish nets or enclosed crustacean traps, their use should be banned in all waters where platypus population are known to occur.

Keywords: anthropogenic mortality, extinction drivers, monotreme, Ornithorhynchidae, platypus conservation, platypus management, predation risk, road trauma, wildlife disease.

References

Allendorf, F. W., England, P. R., Luikart, G., Ritchie, P. A., and Ryman, N. (2008). Genetic effects of harvest on wild animal populations. Trends in Ecology and Evolution 23, 327-337.
| Crossref | Google Scholar | PubMed |

Bethge, P., Munks, S., Otley, H., and Nicol, S. (2003). Diving behaviour, dive cycles and aerobic dive limit in the platypus Ornithorhynchus anatinus. Comparative Biochemistry and Physiology A 136, 799-809.
| Crossref | Google Scholar | PubMed |

Bino, G., Kingsford, R. T., Grant, T., Taylor, M. D., and Vogelnest, L. (2018). Use of implanted acoustic tags to assess platypus movement behaviour across spatial and temporal scales. Scientific Reports 8, 5117.
| Crossref | Google Scholar | PubMed |

Booth, R., and Connolly, J. (2008). Platypuses. In ‘Medicine of Australian Mammals’. (Eds L. Vogelnest, R. Woods.) pp. 103–132. (CSIRO Publishing: Melbourne.)

Brown, P., Hunt, T. L., and Khageswor, G. (2015). Effects of gear type, entrance size and soak time on trap efficiency for freshwater crayfish Cherax destructor and C. albidus. Marine and Freshwater Research 66, 989-998.
| Crossref | Google Scholar |

Brunt, T. (2022). Platypus populations in a subtropical, urban landscape: an analysis of distribution, habitat and connectivity. Ph.D. thesis, University of Queensland: Brisbane, Qld.

Burrell, H. (1927). ‘The Platypus’. (Angus and Robertson: Sydney.)

Caley, P., Ramsey, D. S. L., and Barry, S. C. (2015). Inferring the distribution and demography of an invasive species from sighting data: the red fox incursion into Tasmania. PLoS One 10, e0116631.
| Crossref | Google Scholar | PubMed |

Clavero, M., and Garcia-Berthou, E. (2005). Invasive species are a leading cause of animal extinctions. Trends in Ecology and Evolution 20, 110.
| Crossref | Google Scholar |

Collins, C., and Kays, R. (2011). Causes of mortality in North American populations of large and medium-sized mammals. Animal Conservation 14, 474-483.
| Crossref | Google Scholar |

Coltman, D. W., O’Donoghue, P., Jorgenson, J. T., Hogg, J. T., Strobeck, C., and Festa-Bianchet, M. (2003). Undesirable evolutionary consequences of trophy hunting. Nature 426, 655-658.
| Crossref | Google Scholar | PubMed |

Connolly, J. H., Obendorf, D. L., Whittington, R. J., and Muir, D. B. (1998). Causes of morbidity and mortality in platypus (Ornithorhynchus anatinus) from Tasmania, with particular reference to Mucor amphibiorum infection. Australian Mammalogy 20, 177-187.
| Crossref | Google Scholar |

Connolly, J. H., Claridge, T., Cordell, S. M., Nielsen, S., and Dutton, G. H. (2016). Distribution and characteristics of the platypus (Ornithorhynchus anatinus) in the Murrumbidgee catchment. Australian Mammalogy 38, 58-67.
| Crossref | Google Scholar |

Darimont, C. T., Carlson, S. M., Kinnison, M. T., Paquet, P. C., Teimchen, T. E., and Wilmers, C. C. (2009). Human predators outpace other agents of trait change in the wild. Proceedings of the National Academy of Sciences of the USA 106, 952-954.
| Crossref | Google Scholar | PubMed |

Dawson, J. P., Claridge, A. W., Triggs, B., and Paull, D. J. (2007). Diet of a native carnivore, the spotted-tail quoll (Dasyurus maculatus), before and after an intense wildfire. Wildlife Research 34, 342-351.
| Crossref | Google Scholar |

de Castro, F., and Bolker, B. (2005). Mechanisms of disease-induced extinction. Ecology Letters 8, 117-126.
| Crossref | Google Scholar |

Evans, B. K., Jones, D. R., Baldwin, J., and Gabbott, G. R. J. (1994). Diving ability of the platypus. Australian Journal of Zoology 42, 17-27.
| Crossref | Google Scholar |

Furlan, E. M., Griffiths, J., Gust, N., Handasyde, K. A., Grant, T. R., Gruber, B., and Weeks, A. R. (2013). Dispersal patterns and population structuring among platypuses, Ornithorhynchus anatinus, throughout south-eastern Australia. Conservation Genetics 14, 837-853.
| Crossref | Google Scholar |

Gardner, J. L., and Serena, M. (1995). Spatial organisation and movement patterns of adult male platypus, Ornithorhynchus anatinus (Monotremata: Ornithorhynchidae). Australian Journal of Zoology 43, 91-103.
| Crossref | Google Scholar |

Grant, T. R. (2004). Captures, capture mortality, age and sex ratios of platypuses, Ornithorhynchus anatinus, during studies over 30 years in the upper Shoalhaven River in New South Wales. Proceedings of the Linnean Society of New South Wales 125, 217-226.
| Crossref | Google Scholar |

Grant, T. R. (2007). ‘The Platypus.’ (CSIRO Publishing: Melbourne.)

Grant, T. R., and Bishop, K. A. (1998). Instream flow requirements for the platypus (Ornithorhynchus anatinus): a review. Australian Mammalogy 20, 267-280.
| Crossref | Google Scholar |

Grant, T. R., and Temple-Smith, P. D. (2003). Conservation of the platypus, Ornithorhynchus anatinus: threats and challenges. Aquatic Ecosystem Health and Management 6, 5-18.
| Crossref | Google Scholar |

Grant, T. R., Griffiths, M., and Leckie, R. M. C. (1983). Aspects of lactation in the platypus, Ornithorhynchus anatinus (Monotremata), in waters of eastern New South Wales. Australian Journal of Zoology 31, 881-889.
| Crossref | Google Scholar |

Grant, T. R., Griffiths, M., and Temple-Smith, P. D. (2004a). Breeding in a free-ranging population of platypuses, Ornithorhynchus anatinus, in the upper Shoalhaven River, New South Wales – a 27 year study. Proceedings of the Linnean Society of New South Wales 125, 227-234.
| Crossref | Google Scholar |

Grant, T. R., Lowry, M. B., Pease, B., Walford, T. R., and Graham, K. (2004b). Reducing the by-catch of platypuses (Ornithorhynchus anatinus) in commercial and recreational fishing gear in New South Wales. Proceedings of the Linnean Society of New South Wales 125, 259-272.
| Crossref | Google Scholar |

Grant, T., Serena, M., Williams, G. A., and Temple-Smith, P. (2024). Age determination in the platypus (Ornithorhynchus anatinus) using spur sheath and spur developmental stages: a review. Australian Mammalogy 46, AM24020.
| Crossref | Google Scholar |

Gust, N., and Handasyde, K. (1995). Seasonal variation in the ranging behaviour of the platypus (Ornithorhynchus anatinus) on the Goulburn River, Victoria. Australian Journal of Zoology 43, 193-208.
| Crossref | Google Scholar |

Gust, N., Griffiths, J., Driessen, M., Philips, A., Stewart, N., and Geraghty, D. (2009). Distribution, prevalence and persistence of mucormycosis in Tasmanian platypuses (Ornithorhynchus anatinus). Australian Journal of Zoology 57, 245-254.
| Crossref | Google Scholar |

Handasyde, K. A., McDonald, I. R., and Evans, B. K. (2003). Plasma glucocorticoid concentrations in free-ranging platypuses (Ornithorhynchus anatinus): response to capture and patterns in relation to reproduction. Comparative Biochemistry and Physiology A 136, 895-902.
| Crossref | Google Scholar | PubMed |

Hawke, T., Bino, G., Shackleton, M. E., Ross, A. K., and Kingsford, R. T. (2022). Using DNA metabarcoding as a novel approach for analysis of platypus diet. Scientific Reports 12, 2247.
| Crossref | Google Scholar | PubMed |

Heimlich, J. E., and Ardoin, N. M. (2008). Understanding behavior to understand behavior change: a literature review. Environmental Education Research 14, 215-237.
| Crossref | Google Scholar |

Hill, J. E., DeVault, T. L., and Belant, J. L. (2019). Cause-specific mortality of the world’s terrestrial vertebrates. Global Ecology and Biogeography 28, 680-689.
| Crossref | Google Scholar |

Hing, S., Narayan, E. J., Thompson, R. C. A., and Godfrey, S. S. (2016). The relationship between physiological stress and wildlife disease: consequences for health and conservation. Wildlife Research 43, 51-60.
| Crossref | Google Scholar |

Hoffman, A. A., Rymer, P. D., Byrne, M., Ruthrof, K. X., Whinam, J., McGeoch, M., Bergstrom, D. M., Guerin, G. R., Sparrow, B., Joseph, L., Hill, S. J., Andrew, N. R., Camac, J., Bell, N., Riegler, M., Gardner, J. L., and Williams, S. E. (2019). Impacts of recent climate change on terrestrial flora and fauna: some emerging Australian examples. Austral Ecology 44, 3-27.
| Crossref | Google Scholar |

Kessell, A. E., Boulton, J. G., Dutton, G. J., Woodgate, R., Shamsi, S., Peters, A., and Connolly, J. H. (2014). Haemolytic anaemia associated with Theileria sp. in an orphaned platypus. Australian Veterinary Journal 92, 443-449.
| Crossref | Google Scholar | PubMed |

Khurana, J., Bino, G., and Hawke, T. (2024). Impacts of river regulation and fragmentation on platypuses in the northern Murray-Darling Basin. Marine and Freshwater Research 75, MF24037.
| Crossref | Google Scholar |

Kolomyjec, S. H., Chong, J. Y. T., Blair, D., Gongora, J., Grant, T. R., Johnson, C. N., and Moran, C. (2009). Population genetics of the platypus (Ornithorhynchus anatinus): a fine-scale look at adjacent river systems. Australian Journal of Zoology 57, 225-234.
| Crossref | Google Scholar |

Lewis, S. L., and Maslin, M. A. (2015). Defining the Anthropocene. Nature 519, 171-180.
| Crossref | Google Scholar | PubMed |

Lind, L., Hasselquist, E. M., and Laudon, H. (2019). Towards ecologically functional riparian zones: a meta-analysis to develop guidelines for protecting ecosystem functions and biodiversity in agricultural landscapes. Journal of Environmental Management 249, 109391.
| Crossref | Google Scholar | PubMed |

Macgregor, J. W., Holyoake, C. S., Munks, S. A., Connolly, J. H., Robertson, I. D., Fleming, P. A., and Warren, K. S. (2017). Investigations into individual health and exposure to infectious agents of platypuses (Ornithorhynchus anatinus) in two river catchments in northwest Tasmania. Journal of Wildlife Diseases 53, 258-271.
| Crossref | Google Scholar | PubMed |

Marchant, R., and Grant, T. R. (2015). The productivity of the macroinvertebrate prey of the platypus in the upper Shoalhaven River, New South Wales. Marine and Freshwater Research 66, 1128-1137.
| Crossref | Google Scholar |

Marks, C. A., Obendorf, D., Pereira, F., Edwards, I., and Hall, G. P. (2014). The dispersion and detection patterns of mtDNA-assigned red fox Vulpes vulpes scats in Tasmania are anomalous. Journal of Applied Ecology 51, 1033-1040.
| Crossref | Google Scholar | PubMed |

Martin, L. B. (2009). Stress and immunity in wild vertebrates: timing is everything. General and Comparative Endocrinology 163, 70-76.
| Crossref | Google Scholar | PubMed |

McDougall, P. T., Réale, D., Sol, D., and Reader, S. M. (2006). Wildlife conservation and animal temperament: causes and consequences of evolutionary change for captive, reintroduced and wild populations. Animal Conservation 9, 39-48.
| Crossref | Google Scholar |

McLachlan-Troup, T. A., Dickman, C. R., and Grant, T. R. (2010). Diet and dietary selectivity of the platypus in relation to season, sex and macroinvertebrate assemblages. Journal of Zoology 280, 237-246.
| Crossref | Google Scholar |

McLeod, A. L. (1993). Movement, home range, burrow usage, diel activity and juvenile dispersal of platypuses, Ornithorhynchus anatinus, on the Duckmaloi Weir, N.S.W. Bachelor of Applied Science (Honours) thesis, Charles Sturt University: Bathurst, NSW.

Mijangos, J. L., Bino, G., Hawke, T., Kolomyjec, S. H., Kingsford, R. T., Sidhu, H., Grant, T., Day, J., Dias, K.N., Gongora, J., and Sherwin, W.B. (2022). Fragmentation by major dams and implications for the future viability of platypus populations. Communications Biology 5, 1127.
| Crossref | Google Scholar | PubMed |

Milner, J. M., Nilsen, E. B., and Andreassen, H. P. (2007). Demographic side effects of selective hunting in ungulates and carnivores. Conservation Biology 21, 36-47.
| Crossref | Google Scholar | PubMed |

Mooney, N., and Spencer, C. (2000). Why did the platypus cross the road? Australian Mammalogy 21, 264-267.
| Google Scholar |

Munday, B. L., Whittington, R. J., and Stewart, N. J. (1998). Disease conditions and subclinical infections of the platypus (Ornithorhynchus anatinus). Royal Society of London Philosophical Transactions: Biological Sciences 353, 1093-1099.
| Crossref | Google Scholar | PubMed |

Musser, A., Grant, T., and Turak, E. (2024). Movements of platypuses around and through instream structures and natural barriers in the Jenolan Karst Conservation Reserve, New South Wales. Australian Mammalogy 46, AM23031.
| Crossref | Google Scholar |

Otley, H. M., and le Mar, K. (1998). Observations on the avoidance of culverts by platypus. The Tasmanian Naturalist 120, 48-50.
| Google Scholar |

Pusey, B. J., and Arthington, A. H. (2003). Importance of the riparian zone to the conservation and management of freshwater fish: a review. Marine and Freshwater Research 54, 1-16.
| Crossref | Google Scholar |

Rakick, R., Rakick, B., Cook, L., and Munks, S. (2001). Observations of a platypus foraging in the sea and hunting of a platypus by a wedge-tailed eagle. The Tasmanian Naturalist 123, 2-4.
| Google Scholar |

Roberts, S., and Serena, M. (2024). Use of consolidated time-lapse camera imagery to detect and monitor platypus (Ornithorhynchus anatinus) activity. Australian Mammalogy 46, AM23045.
| Crossref | Google Scholar |

Rosser, A. M., and Manika, S. A. (2002). Overexploitation and species extinctions. Conservation Biology 16, 584-586.
| Crossref | Google Scholar |

Serena, M., and Grant, T. R. (2017). Effect of flow on platypus (Ornithorhynchus anatinus) reproduction and related population processes in the upper Shoalhaven River. Australian Journal of Zoology 65, 130-139.
| Crossref | Google Scholar |

Serena, M., and Williams, G. A. (1998). Rubber and plastic rubbish: a summary of the problem posed to platypus Ornithorhynchus anatinus in suburban habitats. The Victorian Naturalist 115, 47-49.
| Google Scholar |

Serena, M., and Williams, G. (2010). Factors contributing to platypus mortality in Victoria. The Victorian Naturalist 127, 178-183.
| Google Scholar |

Serena, M., and Williams, G. A. (2013). Movements and cumulative range size of the platypus (Ornithorhynchus anatinus) inferred from mark-recapture studies. Australian Journal of Zoology 60, 352-359.
| Crossref | Google Scholar |

Serena, M., and Williams, G. A. (2022). Factors affecting the frequency and outcome of platypus entanglement by human rubbish. Australian Mammalogy 44, 81-86.
| Crossref | Google Scholar |

Serena, M., Thomas, J. L., Williams, G. A., and Officer, R. C. E. (1998). Use of stream and river habitats by the platypus, Ornithorhynchus anatinus, in an urban fringe environment. Australian Journal of Zoology 46, 267-282.
| Crossref | Google Scholar |

Serena, M., Williams, G. A., Weeks, A. R., and Griffiths, J. (2014). Variation in platypus (Ornithorhynchus anatinus) life-history attributes and population trajectories in urban streams. Australian Journal of Zoology 62, 223-234.
| Crossref | Google Scholar |

Serena, M., Grant, T. R., and Williams, G. A. (2016). Reducing bycatch mortality in crustacean traps: effect of trap design on platypus and yabby retention rates. Fisheries Research 175, 43-50.
| Crossref | Google Scholar |

Serena, M., Snowball, G., Thomas, J. L., Williams, G. A., and Danger, A. (2024). Platypus longevity: a new record in the wild and information on captive life span. Australian Mammalogy 46, AM23048.
| Crossref | Google Scholar |

Taylor, R., Mooney, N., and Lange, K. (1991). Observations on platypus. The Tasmanian Naturalist 105, 1-3.
| Google Scholar |

Taylor-Brown, A., Booth, R., Gillett, A., Mealy, E., Ogbourne, S. M., Polkinghorne, A., and Conroy, G. C. (2019). The impact of human activities on Australian wildlife. PloS One 14, e0206958.
| Crossref | Google Scholar | PubMed |

Thomas, J. L., Parrott, M. L., Handasyde, K. A., and Temple-Smith, P. (2020). Maternal care of platypus nestlings. Australian Mammalogy 42, 283-292.
| Crossref | Google Scholar |

Tyson, R. M. (1980). Road killed platypus. The Tasmanian Naturalist 60, 8.
| Google Scholar |

Victorian Fisheries Authority (2017). ‘Victorian Eel Fishery Management Plan.’ (Victorian Fisheries Authority: Melbourne.)

Williams, G. A., Serena, M., and Grant, T. R. (2013). Age-related change in spurs and spur sheaths of the platypus (Ornithorhynchus anatinus). Australian Mammalogy 35, 107-114.
| Crossref | Google Scholar |