Platypus (Ornithorhynchus anatinus) body size, condition and population structure in Tasmanian river catchments: variability and potential mucormycosis impacts
Nick Gust A C and Josh Griffiths A B
+ Author Affiliations
- Author Affiliations
A Department of Primary Industries, Parks, Water and Environment, GPO Box 44, Hobart, Tas. 7001, Australia.
B CESAR Consultants, Suite 102, 55 Flemington Road, North Melbourne, Vic. 3051, Australia.
C Corresponding author. Email: platypus.gust@gmail.com
Wildlife Research 38(4) 271-289 https://doi.org/10.1071/WR10162
Submitted: 10 September 2010 Accepted: 16 May 2011 Published: 6 September 2011
Abstract
Context: Despite widespread interest in platypus (Ornithorhynchus anatinus) conservation, it is unclear how their fundamental morphometric and demographic characteristics differ over a range of scales. This hampers impact assessments and understanding of platypus ecology. Although the ulcerative fungal disease mucormycosis has infected platypuses in Tasmania for three decades, its population level impacts and conservation significance remain unknown.
Aims: This study examined morphometric and demographic patterns in Tasmanian platypuses to provide a basis for investigating impacts of mucormycosis or other anthropogenic disturbances. It also sought to identify important spatial scales of natural variability and the magnitude of seasonal variation in platypus body size, condition and population structure. The hypothesis of higher mucormycosis prevalence and mortality in adult males was also investigated.
Methods: Extensive live-trapping surveys were conducted from January 2008 to July 2009 in 75 streams and 18 river catchments across Tasmania including King Island. The sex, age, body size, tail volume index, health and moult condition of 195 individuals were assessed, and population age and sex structures characterised. Sampling focussed on assessing variability within and between river catchments and compared populations in river catchments with contrasting disease status.
Key results: Differences in platypus morphometrics within and between catchments and seasonal moulting patterns were detected. Adult males had higher fat stores than adult females, especially during winter. This study also provided the first evidence of population level consequences of disease in platypuses. The demographic group most commonly affected by mucormycosis was confirmed to be adult males. Differences in male age structure among catchments of varying disease status were consistent with the hypothesis of higher adult male mortality rates and turnover in currently affected catchments.
Conclusions: More than 25 years after mucormycosis was first detected in Tasmanian platypuses, the disease continues to play a low-level, ongoing role in affected populations.
Implications: The present study provides the first systematic multi-scale spatial investigation of platypus mucormycosis, which contributes to unravelling the epidemiology of the disease and detecting its impacts. By identifying the magnitude and important scales of morphometric and demographic differences in Tasmanian platypuses the study also assists researchers choose comparable demographic groups and spatial scales for meaningful comparisons in future impact studies.
Additional keywords: age structure, disease effects, impact assessment, natural variability, spatial scale.
References
Bethge, P. (2002). Energetics and foraging behaviour of the platypus Ornithorhynchus anatinus. Ph.D. Thesis, University of Tasmania, Hobart.Bethge, P., Munks, S. A., Otley, H., and Nicol, S. (2003). Diving behaviour, dive cycles and aerobic dive limit in the platypus Ornithorhynchus anatinus. Comparative Biochemistry and Physiology Part A 136, 799–809.
| Diving behaviour, dive cycles and aerobic dive limit in the platypus Ornithorhynchus anatinus.Crossref | GoogleScholarGoogle Scholar |
Bethge, P., Munks, S., Otley, H., and Nichol, S. (2009). Activity patterns and sharing of time and space of platypuses, Ornithorhynchus anatinus, in a subalpine Tasmanian lake. Journal of Mammalogy 90, 1350–1356.
| Activity patterns and sharing of time and space of platypuses, Ornithorhynchus anatinus, in a subalpine Tasmanian lake.Crossref | GoogleScholarGoogle Scholar |
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.
Connolly, J., Canfield, P., and Obendorf, D. (2000). Gross, histological and immunohistochemical features of mucormycosis in the platypus. Journal of Comparative Pathology 123, 36–46.
| Gross, histological and immunohistochemical features of mucormycosis in the platypus.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3M%2FgvV2hug%3D%3D&md5=c0ef312f8542e15a3a6d5d1f6cd6aac1CAS |
Daszak, P., Cunningham, A. A., Hyatt, A. D., and Efford, M. (2000). Emerging infectious diseases of wildlife – threats to biodiversity and human health. Science 287, 443–449.
| Emerging infectious diseases of wildlife – threats to biodiversity and human health.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXntl2jtw%3D%3D&md5=b2bf897ddd7d55b1b4f5de147e17ddadCAS |
Dionne, M., Miller, K., Dodson, J., and Berntchez, L. (2009). MHC standing genetic variation and pathogen resistance in wild Atlantic salmon. Philosophical Transactions of the Royal Society B 364, 1555–1565.
| MHC standing genetic variation and pathogen resistance in wild Atlantic salmon.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXmt1ahs7k%3D&md5=30d87fc7468901c36102810829a43a0dCAS |
Ellem, B. A., Bryant, A., and O’Connor, A. (1998). Statistical modelling of platypus (Ornithorhynchus anatinus) habitat preferences using generalised linear models. Australian Mammalogy 20, 281–285.
Frank, W. (1975). Mycotic infections in amphibians and reptiles. In ‘In Proceedings of the 3rd International Wildlife Disease Conference’. (Ed. L. A. Page.) pp. 73–88.
Furlan, E., Umina, P., Mitrovski, P., Gust, N., Griffiths, J., and Weeks, A. (2010). High levels of genetic divergence between Tasmanian and Victorian populations of platypus, Ornithorhynchus anatinus, as revealed by microsatellite loci. Conservation Genetics 11, 319–323.
| High levels of genetic divergence between Tasmanian and Victorian populations of platypus, Ornithorhynchus anatinus, as revealed by microsatellite loci.Crossref | GoogleScholarGoogle Scholar |
Gardner, J., and Serena, M. (1995). Spatial organisation and movement patterns of adult male platypus, Ornithorhynchus anatinus (Monotremata : Ornithorhynchidae). Australian Journal of Zoology 43, 91–103.
| Spatial organisation and movement patterns of adult male platypus, Ornithorhynchus anatinus (Monotremata : Ornithorhynchidae).Crossref | GoogleScholarGoogle Scholar |
Geraghty, D. P., Griffiths, J., Stewart, N., Robertson, I., and Gust, N. (2011). Hematologic, plasma biochemical and other indicators of the health of Tasmanian platypuses (Ornithorhynchus anatinus): predictors of mucormycosis. Journal of Wildlife Diseases 47, 483–493.
| 1:CAS:528:DC%2BC3MXpvFeis7g%3D&md5=59f43c2927e4c0e10a77d1354d8c2da4CAS |
Grant, T. R. (2004a). 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.
Grant, T. R. (2004b). Depth and substrate selection by platypuses, Ornithorhynchus anatinus, in the lower Hastings River, New South Wales. Proceedings of the Linnean Society of New South Wales 125, 235–241.
Grant, T. R. (2007). ‘Platypus.’ 4th edn. (CSIRO publishing: Melbourne.)
Grant, T. R., and Carrick, F. N. (1974). Capture and marking of the platypus, Ornithorhynchus anatinus in the wild. Australian Zoologist 18, 133–135.
Grant, T. R., and Carrick, F. N. (1978). Some aspects of the ecology of the platypus (Ornithorhynchus anatinus) in the Upper Shoalhaven River, NSW. Australian Zoologist 20, 181–199.
Grant, T., and Temple-Smith, P. (1983). Size, seasonal weight change and growth in platypuses, Ornithorhynchus anatinus (Monotremata : Ornithorhynchidae), in rivers and lakes of New South Wales. Australian Mammalogy 6, 51–60.
Grant, T. R., and Temple-Smith, P. D. (2003). Conservation of the platypus, Ornithorhynchus anatinus: threats and challenges. Aquatic Ecosystem Health & Management 6, 5–18.
| Conservation of the platypus, Ornithorhynchus anatinus: threats and challenges.Crossref | GoogleScholarGoogle Scholar |
Grant, T. R., and Whittington, R. W. (1991). The use of freeze-branding and implanted transponder tags as a permanent marking method for platypus Ornithorhynchus anatinus. Australian Mammalogy 14, 147–150.
Gust, N. (2004). Variation in the population biology of protogynous coral reef fishes over tens of kilometres. Canadian Journal of Fisheries and Aquatic Sciences 61, 205–218.
| Variation in the population biology of protogynous coral reef fishes over tens of kilometres.Crossref | GoogleScholarGoogle Scholar |
Gust, N., and Griffiths, J. (2009). Platypus mucormycosis and its conservation implications. Australasian Mycologist 28, 1–8.
Gust, N., and Griffiths, J. (2010). ‘Tasmanian Platypus Management Plan.’ (Department of Primary Industries Parks Water and Environment: Hobart.)
Gust, N., and Handasyde, K. (1995). Seasonal variation in the ranging behaviour of the platypus (Ornithorynchus anatinus) on the Goulburn River, Victoria. Australian Journal of Zoology 43, 193–208.
| Seasonal variation in the ranging behaviour of the platypus (Ornithorynchus anatinus) on the Goulburn River, Victoria.Crossref | GoogleScholarGoogle Scholar |
Gust, N., Griffiths, M., Driessen, M., Phillips, A., Stewart, N., and Geraghty, N. (2009). Distribution, prevalence and persistence of mucormycosis in Tasmanian platypuses (Ornithorhynchus anatinus). Australian Journal of Zoology 57, 245–254.
| Distribution, prevalence and persistence of mucormycosis in Tasmanian platypuses (Ornithorhynchus anatinus).Crossref | GoogleScholarGoogle Scholar |
Handasyde, K. A., McDonald, I. R., and Evans, B. K. (1992). Seasonal changes in plasma concentrations of progesterone in free-ranging platypus (Ornithorhynchus anatinus). In ‘Platypus and Echidna’. (Ed. M. L. Augee.) pp. 75–79. (Royal Zoological Society of NSW: Mosman, NSW.)
Hulbert, A. J., and Grant, T. (1983). A seasonal study of body condition and water turn over in a free-living population of platypuses Ornithorhynchus anatinus (Monotremata). Australian Journal of Zoology 31, 109–116.
| A seasonal study of body condition and water turn over in a free-living population of platypuses Ornithorhynchus anatinus (Monotremata).Crossref | GoogleScholarGoogle Scholar |
Koch, N., Munks, S. A., Utesch, M., Davies, P. E., and McIntosh, P. D. (2006). The platypus Ornithorhynchus anatinus in headwater streams, and effects of pre-code forest clearfelling, in the South Esk River catchment, Tasmania, Australia. Australian Zoologist 33, 458–473.
Kolomyjec, S., Chong, J., Gongora, J., Grant, T., Johnson, C., 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.
| Population genetics of the platypus (Ornithorhynchus anatinus): a fine scale look at adjacent river systems.Crossref | GoogleScholarGoogle Scholar |
Krueger, B., Hunter, S., and Serena, M. (1992). Husbandry, diet and behaviour of platypus Ornithorhynchus anatinus. International Zoo Yearbook 31, 64–71.
| Husbandry, diet and behaviour of platypus Ornithorhynchus anatinus.Crossref | GoogleScholarGoogle Scholar |
McGregor, J. W. (2008). Investigation into the distribution and physical characteristics of the platypus (Ornithorhynchus anatinus), and the distribution and prevalance of mucormycosis in northwest Tasmania. Masters Thesis, Murdoch University, Perth.
McLachlan-Troup, T. (2007). The ecology and functional importance of the platypus (Ornythorhynchus anatinus) in Australian freshwater habitats. Ph.D. Thesis, University of Sydney.
McPherson, G. (Ed.) (2001). ‘Applying and Interpreting Statistics: a Comprehensive Guide.’ 2nd edn. (Springer: New York.)
Munday, B., and Peel, B. F. (1983). Severe ulcerative dermatitis in platypus (Ornithoryhchus anatinus). Journal of Wildlife Diseases 19, 363–365.
| 1:STN:280:DyaL2c%2FmsFSlsQ%3D%3D&md5=12b7372d8a566e06ae979926380f0b94CAS |
Munday, B. L., Whittington, R. J., and Stewart, N. J. (1998). Disease conditions and subclinical infections in the platypus (Ornithorhynchus anatinus). Transactions of the Royal Society of London. Series B. 353, 1093–1099.
| Disease conditions and subclinical infections in the platypus (Ornithorhynchus anatinus).Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK1czos1GktA%3D%3D&md5=e5fb5b2512971b03d52b492ecb475ca6CAS |
Munks, S., Otley, H., Bethge, P., and Jackson, J. (2000). Reproduction, diet and daily energy expenditure of the platypus in a sub-alpine Tasmanian lake. Australian Mammalogy A21, 260–261.
Murray, K. A., Skerratt, L. F., Speare, R., and McCallum, H. (2009). Impact and dynamics of disease in species threatened by the amphibian chytrid fungus Batrachochytrium dendrobatidis. Conservation Biology 23, 1242–1252.
| Impact and dynamics of disease in species threatened by the amphibian chytrid fungus Batrachochytrium dendrobatidis.Crossref | GoogleScholarGoogle Scholar |
Obendorf, D. L., Peel, B. F., and Munday, B. L. (1993). Mucor amphibiorum infection in platypus (Ornithorhynchus anatinus) from Tasmania. Journal of Wildlife Diseases 29, 485–487.
| 1:STN:280:DyaK3szmtVelsg%3D%3D&md5=c9fb7db90e959622164d8366a4b533b6CAS |
Olsson Herrin, R. (2009). Distribution and individual characteristics platypuses (Ornithorhynchus anatinus) in the Plenty River, Southeast Tasmania. Masters Thesis, Lund Univerisity, Sweden.
Piggott, M. P., and Taylor, A. C. (2003). Remote collection of animal DNA and its applications in conservation management and understanding the population biology of rare and cryptic species. Wildlife Research 30, 1–13.
| Remote collection of animal DNA and its applications in conservation management and understanding the population biology of rare and cryptic species.Crossref | GoogleScholarGoogle Scholar |
Pounds, J. A., Bustamante, M. R., Coloma, L. A., Consuegra, J. A., Fogden, M. P. L., Foster, P. N., La Marca, E., Masters, K. L., Merino-Viteri, A., Puschendorf, R., Ron, S. R., Sánchez-Azofeifa, G. A., Still, C. J., and Young, B. E. (2006). Widespread amphibian extinctions from epidemic disease driven by global warming. Nature 439, 161–167.
| Widespread amphibian extinctions from epidemic disease driven by global warming.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XislKiug%3D%3D&md5=c884dc88337e0e2adc88ba79274e05d0CAS |
Quinn, G., and Keough, M. (2002). ‘Experimental Design and Data Analysis for Biologists.’ (Cambridge University Press: Cambridge.)
Rohweder, D. A., and Baverstock, P. R. (1999). Distribution of the platypus Ornithorhynchus anatinus in the Richmond River catchment, northern New South Wales. Australian Zoologist 31, 30–37.
Rounsevell, D. E., Taylor, R. J., and Hocking, G. J. (1991). Distribution records of native terrestrial mammals in Tasmania. Wildlife Research 18, 699–717.
| Distribution records of native terrestrial mammals in Tasmania.Crossref | GoogleScholarGoogle Scholar |
Sale, P. (1998). Appropriate spatial scales for studies of reef fish. Australian Journal of Ecology 23, 202–208.
| Appropriate spatial scales for studies of reef fish.Crossref | GoogleScholarGoogle Scholar |
Serena, M., Thomas, J., Williams, G., and Officer, R. (1998). Use of stream and river habitats by the platypus, Ornithorhynchus anatinus, in an urban fringe environment. Australian Journal of Zoology 46, 267–282.
| Use of stream and river habitats by the platypus, Ornithorhynchus anatinus, in an urban fringe environment.Crossref | GoogleScholarGoogle Scholar |
Serena, M., Morley, M., Swinnerton, M., and Williams, G. A. (2001). Effect of food availability and habitat on the distribution of platypus (Ornithorhynchus anatinus) foraging activity. Australian Journal of Zoology 49, 263–277.
| Effect of food availability and habitat on the distribution of platypus (Ornithorhynchus anatinus) foraging activity.Crossref | GoogleScholarGoogle Scholar |
Skalski, J. R., Ryding, K. E., and Millspaugh, J. J. (2005). ‘Wildlife Demography: Analysis of Sex, Age and Count Data.’ (Elsevier Acadmeic Press: Burlington, MA.)
Skerratt, L. F., Berger, L., Speare, R., Cashins, S., McDonald, K. R., Phillott, A. D., Hines, H. B., and Kenyon, N. (2007). Spread of chytridiomycosis has caused the rapid global decline and extinction of frogs. EcoHealth 4, 125–134.
| Spread of chytridiomycosis has caused the rapid global decline and extinction of frogs.Crossref | GoogleScholarGoogle Scholar |
Speare, R., Thomas, A., O’Shea, P., and Shipton, W. (1994). Mucor amphibiorum in the toad (Bufo marinus) in Australia. Journal of Wildlife Diseases 30, 399–407.
| 1:STN:280:DyaK2M%2FhvVymtA%3D%3D&md5=5163b972346b5e7a93c0369007f10e3bCAS |
Stewart, N. J. (2001). The epidemiology of ulcerative mycosis of the platypus (Ornithorynchus anatinus). Ph.D Thesis, University of Tasmania, Hobart.
Strahler, A. N. (1957). Quantitative analysis of watershed geomorphology. Transactions of the American Geophysical Union 8, 913–920.
Temple-Smith, P. D. (1973). Seasonal breeding biology of the platypus, Ornithorhynchus anatinus (Shaw 1799), with special reference to the male. Ph.D. Thesis, Australian National University, Canberra.
Tyndale-Biscoe, H. (2005). ‘Life of Marsupials.’ (CSIRO Publishing: Melbourne.)
Turnbull, R. W. (1998). Distribution of the platypus (Ornithorhynchus anatinus) in the Bombala River catchment, south-eastern New South Wales. Australian Mammalogy 20, 251–256.
Vine, S., Crowther, M., Lapidge, S., Dickman, C., Mooney, N., Piggott, M., and English, A. (2009). Comparison of methods to detect rare and cryptic species: a case study using the red fox (Vulpes vulpes). Wildlife Research 36, 436–446.
| Comparison of methods to detect rare and cryptic species: a case study using the red fox (Vulpes vulpes).Crossref | GoogleScholarGoogle Scholar |
Whittington, R. J. (1992). The role of infectious diseases in the population biology of monotremes. In ‘Platypus and Echidnas’. (Ed. M. L. Augee.) pp. 285–292. (Royal Zoological Society NSW: Sydney.)
Whittington, R. J., Connolly, J. H., Obendorf, D. L., Emmins, J., Grant, T. R., and Handasyde, K. A. (2002). Serological responses against the pathogenic dimorphic fungus Mucor amphibiorum in populations of platypus (Ornithorhynchus anatinus) with and without ulcerative mycotic dermatitis. Veterinary Microbiology 87, 59–71.
| Serological responses against the pathogenic dimorphic fungus Mucor amphibiorum in populations of platypus (Ornithorhynchus anatinus) with and without ulcerative mycotic dermatitis.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD38zjsFGiuw%3D%3D&md5=e8d6f6a7a3df7d0fe404548c6adb4651CAS |
