Miscellaneous Mammals 3: The Long-Nosed Potoroo

Long-Nosed Potoroo

 Sharing the enclosure of the Sugar Gliders I discussed last week is our pair of Long-Nosed Potoroos, Potorous tridactylus. These are strange and specialised relatives of the kangaroos and wallabies and along with a few related species are placed in the family Potoridae. The group is sometimes referred to as rat-kangaroos, but these days they are usually referred to as Potoroos or Bettongs. They seem to be a very ancient group, and seem to have retained the ancient lifestyle of the common ancestor they share with the more open-country adapted wallabies and true kangaroos.

As with many mammals, potoroos are nocturnal for the most part, living solitary lives except when breeding. Both sexes are territorial, and although they are little studied they appear to love to dig, both for food and for shelter.

Unfortunately, potoroos, like many other Australian native species, have suffered considerably since human, and especially European, colonisation of Australia. Too frequent burning removes the dense understorey they require, and introduced predators like cats and foxes are serious threats. As it seems to be a bit more of a habitat generalist than its relatives (Gilbert’s Potoroo is known from only one site and under 50 individuals) the Long-Nosed Potoroo is currently rated by the IUCN as of Least Concern, although even they are decreasing. Since the arrival of Europeans, two species have become extinct.

Gilberts Potoroo

Potoroos as a group have an unusual specialisation – they feed largely (at least 70%) on fungi, especially those that produce their fruiting bodies underground. There are a large number of different species of such fungi, but several are known to human gastronomy – in European cookery they are called truffles, and various species are extremely highly prized – in December 2009 White Truffles Tuber album were selling for €10,200 per kilo. Truffles have an extremely powerful scent, and are used in very small quantities in haute cuisine – often shaved finely over pasta or used as thin slices in meat dishes.

Not surprisingly, there have been many attempts to cultivate culinary truffles, and at least some species are now being commercially produced – the truffle fungus is a mycorrhizal symbiont of various trees, and by infecting seedlings of the appropriate trees with the fungus, it is possible to produce truffle plantations.

To return to the potoroos, the truffle species they use are as far as I know not used in cookery, but are extremely important to the ecosystem. The reason they produce scents which attract the potoroos is that they spread the spores of the fungus in their droppings, just as berry bearing plants use birds to spread their seeds. An absence of potoroos could thus have serious long term consequences for their habitats, as in the nutrient poor soils of Australia mycorrhizal fungi are particularly important for nutrient uptake by native plants. Other than fungi, potoroos feed on some plant material and will also eat invertebrates. This more generalist diet led some fossil potoroos in a predatory direction – Propleopus was a 70kg creature that seemed to have had an omnivorous diet and was certainly capable of eating meat.

Outside Australia, the only species of Potoridae that can be seen in zoos are the Long Nosed Potoroo and its relative the Brush-Tailed Bettong. The only Long-Nosed Potoroos in the US are at the Kangaroo Conservation centre in Georgia. Bettongs can be seen in both US and European zoos.

(images from wikipedia)