EPOW - Ecology Picture of the Week

Platypus Play

Duck-billed Platypus (Ornithorhynchus anatinus)
Family Ornithorhynchidae, Order Monotremata
Tasmania, Australia 

Explanation:  Cruising this quiet stream in Tasmania, and in a farm stock pond in Queensland, northern Australia, are these male duck-billed platypuses. 

What a strange and wonderful -- and endangered -- creature this is.  

It is often well described as having a duck-like bill, webbed feet, horny plates instead of teeth in the adults, tiny eyes like a mole's, a flattened tail like a beaver's, and even a venom gland on an ankle spur, used during territorial conflicts between males.  

Along with echidnas, they constitute monotremes which are the only mammals on earth that lay eggs.  And the platypus is the sole species member of its family, the Ornithorhynchus or "bird-nose" (thus, "duck-billed").  The bill is used as an electrosensory organ to locate prey beneath the water by feeling small changes in the electrical field.  In fact, when they dive, platypuses close their eyes.   

They seem to keep well in captivity, although the sexes avoid each other except when to mate.   Their natural range is scattered throughout the eastern edge of Australia and into Tasmania.  They burrow into stream banks in which to make their dens.

Recently, scientists have unraveled their genome.  Such research can help to determine which platypus populations might be isolated in the wild, and thus deserving of local conservation or restoration attention.  

The name platypus is derived from the Greek "platys" (flat) and "pous" (foot):  the platypus is thus a flat-footed, egg-laying, venomous-spurred, burrow-digging, electro-receptive, horny-plate-toothed, duck-billed mammal.  

Unique in the true sense of the word!

Information:
     Fjällbrant, T.T., P.R. Manger, and J.D. Pettigrew.  1998.  Some related aspects of platypus electroreception: temporal integration behaviour, electroreceptive thresholds and directionality of the bill acting as an antenna.  Philos. Trans. R. Soc. Lond. B. Biol. Sci. 353(1372):1211–1219.
     Pettigrew, J.D.  1999.  Electroreception in monotremes.  The Journal of Experimental Biology 202:1447-1454.