Native water rats have worked out how to safely eat cane toads

October 24, 2019 6:08 PM

Eat your heart out: native water rats have worked out how to safely eat cane toads

Australia’s water rats, or Rakali, are one of Australia’s beautiful but lesser-known native rodents. And these intelligent, semi-aquatic rats have revealed another talent: they are one of the only Australian mammals to safely eat toxic cane toads... The rats, which can grow to over 1kg, are the only mammal found to specifically target large toads, neatly dissecting the toads to eat their hearts and livers while avoiding the poisonous skin and glands.

Previously.

posted by Fiasco da Gama (22 comments total)

Natural Selection is crazy...
posted by Windopaene at 6:11 PM on October 24, 2019 [2 favorites]

This might counted as ecosystem assembly...
posted by SaltySalticid at 6:13 PM on October 24, 2019

We've lined up a fabulous type of gorilla that thrives on snake meat.

Then we're stuck with gorillas!

No, that's the beautiful part. When wintertime rolls around, the gorillas simply freeze to death.
posted by snofoam at 6:39 PM on October 24, 2019 [15 favorites]

This is very cool. I wouldn't, however, have called those critters beautiful … until I got a look at the toad.
posted by allthinky at 6:42 PM on October 24, 2019

Even more impressive when you find out about the intricate occult rituals the water rats use the toads' hearts and livers for.
posted by sugar and confetti at 7:02 PM on October 24, 2019 [21 favorites]

But despite medium toads being far more common, three quarters of the dead toads we found were large, and the remainder were medium. No small toad bodies were found or observed being attacked.

The rats are... waiting for the toads to get bigger before eating them? They're managing the toads like livestock?
posted by um at 7:35 PM on October 24, 2019 [23 favorites]

Cue JeffGoldblum-nature-finds.gif ... This is pretty fascinating.
posted by Greg_Ace at 7:44 PM on October 24, 2019 [1 favorite]

They should team up with the orcas that go after shark liver

Or the warthog-riding baboons.
posted by Greg_Ace at 7:45 PM on October 24, 2019

Don't bet against rats.
posted by IAmUnaware at 7:59 PM on October 24, 2019

The toads secrete a toxin in their parotoid glands (on the back, neck and shoulders) that can be fatal even in very small doses.

Followed immediately by a picture of someone's hand holding one. Yeah, I know, they're not holding it by the back, neck or shoulders, but good God man, that's what those long pizza oven stick things are for.

During our study we captured and measured more than 1,800 cane toads in just 15 days in the vicinity of the water rats’ creek.

Yeah, with the pizza oven stick thing, right?
posted by BigHeartedGuy at 8:10 PM on October 24, 2019 [8 favorites]

Seems like the rakali realise that it's not really worth the bother of going after the little ones. The larger ones will have bigger eatable bits, and the hind legs worth skinning and eating as well. Conservation of energy.
posted by Athanassiel at 8:45 PM on October 24, 2019 [2 favorites]

Could they ever eat enough of the toads to put a dent in their population, even locally?
posted by Dip Flash at 9:16 PM on October 24, 2019 [2 favorites]

Some way, some how, nature in Australia will find a way to kill you. I salute you, resourceful rats.
posted by emjaybee at 10:02 PM on October 24, 2019 [12 favorites]

Finally some good news!
posted by monotreme at 10:36 PM on October 24, 2019 [5 favorites]

Unfortunately this is unconnected to the other rat-related news I saw this week, and the rats aren't killing the toads the way most people in South East Queensland seem to do by just running them over with their cars.
posted by MarchHare at 10:51 PM on October 24, 2019 [6 favorites]

running over cane toads

I know I've made a clean kill, particularly if the toad is actually facing towards the vehicle because the air that's inside the toad is trapped within the head and blown out towards the back and the toad really goes off with a bang.
posted by ryanrs at 12:43 AM on October 25, 2019 [1 favorite]

Can people teach rats how to eat toads? Maybe show them a video of other rats doing so successfully? Just curious -- it seems unlikely, and yet...
posted by amtho at 1:07 AM on October 25, 2019 [2 favorites]

Good job, water rats!
posted by kitten magic at 3:36 AM on October 25, 2019

IIRC cane toads are particularly easy prey if you know how to eat one. Their instinct is to not waste energy by hopping away, but rather to just sit still while being attacked and let the poison do its work. Crows will just hop into a group of cane toads and leisurely graze on them by flipping them over one by one and eviscerating them.
posted by xthlc at 7:28 AM on October 25, 2019 [3 favorites]

The finding intrigued us enough to dissect waterlogged and rotting toad bodies in 40℃ heat. This just makes field work sound so glamorous . . . The things people do for science. Bless them.
posted by mercredi at 7:50 AM on October 25, 2019 [1 favorite]

Heh, this is oddly reminiscent of the feeding habits of the Hooder, a particularly nasty critter from Neal Asher’s Polity-series (which btw excels in scary ecosystems).
posted by bouvin at 12:25 PM on October 25, 2019

Can people teach rats how to eat toads? Well, they can teach them how to drive, so i don't see why not.
posted by ambulocetus at 6:38 AM on October 26, 2019