Register      Login
Australian Mammalogy Australian Mammalogy Society
Journal of the Australian Mammal Society
RESEARCH ARTICLE

Age-related change in spurs and spur sheaths of the platypus (Ornithorhynchus anatinus)

G. A. Williams A , M. Serena A C and T. R. Grant B
+ Author Affiliations
- Author Affiliations

A Australian Platypus Conservancy, PO Box 22, Wiseleigh, Vic. 3885, Australia.

B School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia.

C Corresponding author. Email: platypus.apc@westnet.com.au

Australian Mammalogy 35(1) 107-114 https://doi.org/10.1071/AM12011
Submitted: 22 February 2012  Accepted: 25 July 2012   Published: 26 October 2012

Abstract

Non-invasive techniques for age assessment of wild mammals are needed for effective species management as well as research. In the case of the platypus, we investigated how morphology of calcaneal spurs and associated features in males and vestigial spur sheaths in females varies with age. Total spur length in males (spur tip to base of subtending epidermal collar) is greatest at 19–24 months and falls thereafter, with significant linear relationships evident between spur length and age of subadults (13–24 months old) and adults (≥25 months old). However, collar length/total spur length discriminates better between subadults and older animals than either collar length or total spur length alone. Juveniles can be reliably identified up to the age of 12 months (males) and 9 months (females) by the presence, respectively, of a sheath encasing the spur or a rudimentary spur sheath. A small proportion of young subadults (males, 4%; females, ≤2%) will be misclassified as juveniles due to sheaths being retained for longer than normal. Studies that need to identify juveniles very accurately as an age class should avoid sampling populations from August–October on the south-eastern Australian mainland (or May–October if subadult males also need to be identified correctly).

Additional keywords: platypus age classes, crural venom system, monotreme, secondary sexual characteristic.


References

Burrell, H. (1974). ‘The Platypus.’ 2nd edn. (Rigby Ltd: Adelaide.)

Connolly, J. H., and Obendorf, D. L. (1998). Distribution, captures and physical characteristics of the platypus (Ornithorhynchus anatinus) in Tasmania. Australian Mammalogy 20, 231–237.

De-La-Warr, M., and Serena, M. (1999). Observations of platypus Ornithorhynchus anatinus mating behaviour. The Victorian Naturalist 116, 172–174.

Easton, L., Williams, G., and Serena, M. (2008). Monthly variation in observed activity of the platypus Ornithorhynchus anatinus. The Victorian Naturalist 125, 104–109.

Gipson, P. S., Ballard, W. B., Nowak, R. M., and Mech, L. D. (2000). Accuracy and precision of estimating age of gray wolves by tooth wear. Journal of Wildlife Management 64, 752–758.
Accuracy and precision of estimating age of gray wolves by tooth wear.Crossref | GoogleScholarGoogle Scholar |

Gordon, G. (1991). Estimation of the age of the koala, Phascolarctos cinereus (Marsupialia: Phascolarctidae) from tooth wear and growth. Australian Mammalogy 14, 5–12.

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.

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 Temple-Smith, P. D. (1983). Size, seasonal weight change and growth in platypuses, Ornithorhynchus anatinus (Monotremata: Ornithorhynchidae), from rivers and lakes of New South Wales. Australian Mammalogy 6, 51–60.

Grant, T. R., and Whittington, R. J. (1991). The use of freeze-branding and implanted transponder tags as a permanent marking method for platypuses, Ornithorhynchus anatinus (Monotremata: Ornithorhynchidae). Australian Mammalogy 14, 147–150.

Grant, T. R., Griffiths, M., and Temple-Smith, P. D. (2004). 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.

Green, H. L. H. (1937). The development and morphology of the teeth of Ornithorhynchus. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 228, 367–420.
The development and morphology of the teeth of Ornithorhynchus.Crossref | GoogleScholarGoogle Scholar |

Griffiths, M. (1978). ‘The Biology of the Monotremes.’ (Academic Press: New York.)

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.
Seasonal variation in the ranging behaviour of the platypus (Ornithorhynchus anatinus) on the Goulburn River, Victoria.Crossref | GoogleScholarGoogle 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 136A, 895–902.

Hawkins, M., and Battaglia, A. (2009). Breeding behaviour of the platypus (Ornithorhynchus anatinus) in captivity. Australian Journal of Zoology 57, 283–293.
Breeding behaviour of the platypus (Ornithorhynchus anatinus) in captivity.Crossref | GoogleScholarGoogle Scholar |

Hewison, A. J. M., Vincent, J. P., Angibault, J. M., Delorme, D., Van Laere, G., and Gaillard, J. M. (1999). Test of estimation of age from tooth wear on roe deer of known age: variation within and among populations. Canadian Journal of Zoology 77, 58–67.
Test of estimation of age from tooth wear on roe deer of known age: variation within and among populations.Crossref | GoogleScholarGoogle Scholar |

Holland, N., and Jackson, S. M. (2002). Reproductive behaviour and food consumption associated with the captive breeding of platypus (Ornithorhynchus anatinus). Journal of Zoology 256, 279–288.
Reproductive behaviour and food consumption associated with the captive breeding of platypus (Ornithorhynchus anatinus).Crossref | GoogleScholarGoogle Scholar |

Hoogland, J. L., and Hutter, J. M. (1987). Using molar attrition to age live prairie dogs. Journal of Wildlife Management 51, 393–394.
Using molar attrition to age live prairie dogs.Crossref | GoogleScholarGoogle Scholar |

Hulbert, A. J., and Grant, T. R. (1983). A seasonal study of body condition and water turnover 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 turnover in a free-living population of platypuses, Ornithorhynchus anatinus (Monotremata).Crossref | GoogleScholarGoogle Scholar |

Koh, J. M. S., Bansal, P. S., Torres, A. M., and Kuchel, P. W. (2009). Platypus venom: source of novel compounds. Australian Journal of Zoology 57, 203–210.
Platypus venom: source of novel compounds.Crossref | GoogleScholarGoogle Scholar |

Kuze, N., Malim, T. P., and Kohshima, S. (2005). Developmental changes in the facial morphology of the Borneo orangutan (Pongo pygmaeus): possible signals in visual communication. American Journal of Primatology 65, 353–376.
Developmental changes in the facial morphology of the Borneo orangutan (Pongo pygmaeus): possible signals in visual communication.Crossref | GoogleScholarGoogle Scholar |

Serena, M., and Williams, G. A. (2012). Effect of sex and age on temporal variation in the frequency and direction of platypus (Ornithorhynchus anatinus) captures in fyke nets. Australian Mammalogy 34, 75–82.
Effect of sex and age on temporal variation in the frequency and direction of platypus (Ornithorhynchus anatinus) captures in fyke nets.Crossref | GoogleScholarGoogle Scholar |

Temple-Smith, P. D. (1973). Seasonal breeding of the platypus, Ornithorhynchus anatinus (Shaw, 1799), with special reference to the male. Ph.D. Thesis, Australian National University, Canberra.

Temple-Smith, P., and Grant, T. (2001). Uncertain breeding: a short history of reproduction in monotremes. Reproduction, Fertility and Development 13, 487–497.
Uncertain breeding: a short history of reproduction in monotremes.Crossref | GoogleScholarGoogle Scholar |

Van Horn, R. C., McElhinny, T. L., and Holekamp, K. E. (2003). Age estimation and dispersal in the spotted hyena (Crocuta crocuta). Journal of Mammalogy 84, 1019–1030.
Age estimation and dispersal in the spotted hyena (Crocuta crocuta).Crossref | GoogleScholarGoogle Scholar |