‘Deadly Rat’ Uses Poison to Kill Attackers
By Anissa Haddadi | August 3, 2011 7:17 PM EST
According to a new scientific report, a species of rat has masterminded an ingenious strategy that will see any predators that try to eat it fail miserably.
The team behind the new study, based in Oxford and regrouping researchers from the UK, Kenya and the U.S., says that African crested rat chew the roots and bark of a highly toxic tree, and then proceed to spread the highly poisonous mixture on its specially adapted fur, leading its attackers to come into contact with the potentially deadly poison.
Researchers write in the Proceedings of the Royal Society B point out that is the first time that this behaviour has been reported in a mammal.
"The need to deter predators has led to one of the most extraordinary defences known in the animal kingdom," said Jonathan Kingdon, who works for the University of Oxford and led the study.
As the predator rushes in and tries to make its first bite, the rat ensures the flank is the first thing the predator encounters," he added.
The team, will now focus on trying to understand how the rodent is able to survive a dose of the toxin, which comes from the poisonous arrow tree also called Acokanthera schimperi and was traditionally used by hunters to kill elephants.
The African crested rat aslo called Lophiomys imhausi is found in the north east of continent, and has long been thought to be poisonous as over the years numerous reports of domestic dogs dying after trying to bite one of the rodents regularly emerged.
It is however the first time that scientists realise the rats actually used a plant to make itself deadly.
Scientist also noted that surprisingly, when an African crested rats is under attack from predators such as jackals, wild cats and leopards, it does not try to escape, but rather slows down it cadence before freezing and exposing the bold, black-and-white-striped tract of hairs that run down its flank wich are imprinted with the poisonous mixture.
"As the predator rushes in and tries to make its first bite, the rat ensures the flank is the first thing the predator encounters: it advertises this visually with its colouring," explained Professor Kingdon.
In most cases, the tactic is successful; the team says as if the predator does not die from their toxic encounter, it is unlikely to ever want to take a bite of the rat again.
The only animal, said Professor Kingdon that uses a similar trick is the hedgehog as it has been proven that the prickly animal sometimes kill a toad and bite into its glands, then smear this toxic mixture on its spikes.
However, the poison seems to boost any discomfort its spikes might cause, rather than have a lethal effect on its predator.
The researchers now want to find out more about this unusual evolutionary relationship between predator, plant and prey.
They are also keen to discover how and why this rat is able to withstand this poison when so many other animals cannot.
The team said this could have interesting medical implications.
Isolating the part of the poison that helps the heart beat and identifying the physiological components of the rat that prevents it from dying could help to lead to novel treatments for heart problems.
"The poison is an organic poison. We all have minute quantities of it in our bodies, and it controls the strength of the heartbeat.
"But if you have too much, your heart beats so hard that you have a heart attack.
"It is the source of the deadly arrow poison that is used to kill elephants" Professor kingdom said.
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