Saturday, 1 January 2011

Hello possum

The is the black eared possum (Didelphis aurita), also known as the Gambá-de-orelha-preta or Saruê, a species of opossum found in Brazil, Argentina and Paraguay. A bit bigger than other possums in South America (60 to 90 inches long and up to 1.6 kg), but with a relatively shorter tail as it's not in the trees quite so much. They do climb of courrse, just not so fast or dexterously. On the other hand, on the ground they are faster than other possums and it's been shown they can see quite a lot further.

Photos courtesy of Heliana Soneghet Pacheco

Although possums do look a little like rats, in fact they are marsupials. The mother gives birth after about 13 days to 8 tiny possums which crawl into a pouch and then suckle for about 100 more days. By the end they are quite a weight to carry around! Babies born at the end of one breeding season are able to reproduce at the start of the next , which can lead to a lot of possums. Actually, possums tend to spread out as they are quite territorial, especially the females, with about 0.5 to 1.5ha depending on how good the territory is.

So what do possums eat? Well, pretty much everything. Insects, fruit and lots of small mammals, they have actually been recommended for keeping down levels of mice. Rather more impressively, they also go for snakes! Somehow they manage partial or even complete immunity to the venom of many species including the fer-de-lance, Bothrops asper, whose bite can be fatal to humans.

When they meet something too big to eat, and too fast to run from, they "play possum", ie. play dead. This can be surprisingly convincing, even including a smelly secretion to suggest that they've started to "go off". As many predators prefer live food this is worth a try as a last resort, but it doesn't work terribly well against oncoming traffic. Nonetheless the Saruê is a success story, and has otherwise adapted well to the modern Mata Atlantica.


rohrerbot said...

That's a very interesting that it eats mice and rats. Happy New Year!

Steven said...

"This can be surprisingly convincing, even including a smelly secretion to suggest that they've started to "go off""

I have known people like that :)

happy New year.