Adult length: 400-630 millimetres (males), 370-550 millimetres (females) (Van Dyck et al. 2013)
Adult weight: 0.8-3.0 kilograms (males), 0.6-1.7 kilograms (females) (Van Dyck et al. 2013). Animals living in the colder/southern parts of the platypus’s range tend to be larger than those found in the warmer/northern parts of its range (Furlan et al. 2011).
Age when first mature: 2 years (Temple-Smith 1973; Grant et al. 2004)
Platypus mating period: Late winter to spring on the Australian mainland (Griffiths 1978; Temple-Smith and Grant 2001); can occur as late as in early summer in Tasmania (Roberts and Serena 2024)
Size of platypus eggs: 16-18 millimetres long x 14-15 millimetres wide (Burrell 1927)
Number of babies in a litter: 1-3 (most typically 2) (Burrell 1927)
Duration of platypus gestation: Estimates range from 13-23 days in captivity; average value = 16 days (Thomas et al. 2020)
Duration of egg incubation: Estimated to be 10-11 days (Griffiths 1978)
Lactational period in the wild: Approximately 3.5 months (Grant et al. 2004)
Maximum platypus life span: A long-term population study near Melbourne found that 40% of adults were last captured when 3-5 years old, 36% when 6-8 years old and 24% when 9 or more years old (Serena et al. 2014). More recently, life spans of up to 24 years in the wild and 30 years in captivity have been recorded (Serena et al. 2024) – for more details, click here.
Photo courtesy of Pete Walsh
LITERATURE CITED
Burrell, H (1927) The Platypus. Angus & Robertson: Sydney.
Furlan E, Griffiths J, Gust N, Armistead R, Mitrovski P, Handasyde KA, Serena M, et al. (2011) Is body size variation in the platypus (Ornithorhynchus anatinus) associated with environmental variables? Australian Journal of Zoology 59, 201-215.
Grant TR, Griffiths M and Temple-Smith PD (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.
Griffiths M (1978) The Biology of the Monotremes. Academic Press: New York.
Roberts S and Serena M (2024) Use of consolidated time-lapse camera imagery to detect and monitor platypus (Ornithorhynchus anatinus) activity. Australian Mammalogy 46, in press. doi:10.1071/AM23045
Serena M, Williams GA, Weeks AR 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.
Serena M, Snowball G, Thomas JL, Williams GA and Danger A (2024) Platypus longevity: a new record in the wild and information on captive life span. Australian Mammalogy 46, in press. doi:10.1071/AM23048
Temple-Smith PD (1973) Seasonal breeding biology of the platypus, Ornithorhynchus anatinus (Shaw 1799), with special reference to the male. PhD 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.
Thomas JL, Parrott ML, Handasyde KA and Temple-Smith P (2020) Maternal care of platypus nestlings (Ornithorhynchus anatinus). Australian Mammalogy 42, 283-292.
Van Dyck S, Gynther I and Baker A (2013) Field Companion to The Mammals of Australia. New Holland Publishers: Sydney.