Nobody loves a dirty rat, right? But what about an African giant pouched rat, a goliath-sized rodent weighing 1.5-2kg (3-4 times the size of our own brown rat) and native to the savannahs of southern Africa?
Over the past 25 years, these giant rats – known as ‘hero rats’ by the people who train them – have been used to detect deadly land mines and tuberculosis pathogens in samples.
Now, there’s even more reason to love them because they could play an important role in fighting the illegal wildlife trade, thanks to their amazing sense of smell.
Research carried out by scientists from the non-profit group APOPO has demonstrated that giant rats can successfully detect samples of elephant ivory, rhino horn, pangolin scales and African hardwood, even when these lucrative wildlife products were mixed with non-target items.
Of course, law enforcement officials already have high-tech scanners and detection dogs to help them in the fight against the multi-billion dollar illegal wildlife trade, so why the need for an army of rats?
Well, says senior research scientist Isabelle Szott and one of the co-authors of a paper demonstrating the rats’ efficacy, they could have several advantages over more traditional detection methods.
First of all, a detection rat costs about $8,000 to train compared with up to $30,000 for a dog. Airport scanners, meanwhile, can cost anywhere between $30,000 and $1.2 million.
“Their light weight is also an important aspect for wildlife product detection,” says Szott, “because we can lift rats to higher locations such as air ventilation systems of shipping containers.” They can go where dogs cannot, in other words.
Finally, dogs often have to work with the same handler, while the rats are far less choosy, making them a more flexible option.
As well demonstrating proof-of-principle, APOPO carried out successful trials at Tanzania’s Dar es Salaam port. Now, it’s a question of rolling out the rats to other ports and airports around the world.
APOPO is cooperating closely with the Tanzanian Wildlife Management Authority, who oversaw the port trials, and it is likely that the country will employ them in the future. “We have also had interest from ports in Singapore and France,” says Szott’s co-author Kate Webb, assistant professor in psychiatry and behavioural sciences at Duke University.
‘Hero rats’ doesn’t do them justice – surely they should be known as ‘super rats’ from now on.
Main image: African giant pouched rat/Betty Nandera Kate Fei-Toto
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