To the untrained British eye the echidna looks like a hedgehog that spends every evening at the gym and all its pocket money on steroids. However there’s far more to it than that, and like many of the other critters on our Mammals Hit List it is seriously weird. Here’s what you need to know …
PHOTO CREDIT: Lyle Radford/lyleradford.com.au [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)%5D, via Wikimedia Commons
The Short-beaked Echidna, which is the type found in Australia, measures up to around 45 centimetres in length and weighs up to 5 kilos compared with a UK hedgehog in tip-top condition which grows up to around 25 centimetres and weighs up to two kilos. Remarkably echidnas are reported to have the world’s biggest fleas, which measure a scratch-inducing 4mm.
An echidna’s spines, which reach 50 mm in length, are in fact modified hairs. Fur can still be found between the spines; this provides insulation, and is longer and thicker in the Tasmanian subspecies, reflecting the colder temperatures on the Apple Isle. Tasmanian echidnas are also bigger than their mainland counterparts.
Unsurprisingly for a critter that’s also known as the spiny anteater, the echidna dines out on ants and termites, but won’t turn up its snout at grubs, larvae and worms either. That snout is specially adapted, and can sense electrical signals from insect bodies. On detecting prey, the echidna uses its long, sharp claws and short, strong legs to dig into the soil and expose the invertebrates. It then licks them up with its tongue, which is 15cm long and covered with sticky mucous. The echidna’s Latin name is Tachyglossus; it means fast-tongue, which is plainly well deserved.
The echidna’s main claim to fame is that, along with platypus it is an egg-laying mammal, or monotreme. However, the egg isn’t laid in a nest. Rather, it’s laid directly into a pouch on the female’s body, where it hatches after 10 days. The young echidna, or puggle, spends most of its first two or three months in the pouch, by which time the growing spines are causing such discomfort that the female evicts the youngster for good.
This brilliant piece of film from National Geographic shows the echidna’s egg, and later a tiny pink puggle. Amazing! Another notable feature of echidnas is that unlike “normal” mammals they have no nipples, but instead the mother feeds the puggle with milk that simply oozes through patches in her skin.
The mating behaviour of echidnas is also bizarre, with “trains” of up to ten randy males pursuing a female in season for hours on end. The males don’t fight, they simply follow, until the female finally succumbs and allows one of them to have his wicked way with her, using his remarkable – and I’m not joking here – his truly remarkable four-headed penis. Did I mention that echidnas are weird?
The “echidna train” behaviour is not fully understood and is rarely witnessed, but was filmed a few months ago in Sydney’s Taronga Zoo. Breeding echidnas in zoos is difficult, so Taronga must be doing something right. The good news is that echidnas are common, and are said to be the most widespread native animal throughout Australia. Let’s hope we see one on our travels.