How Rasputin the Rat astounded scientists

For nearly five months, he led his pursuers a merry dance, swimming nearly half a kilometre across open sea to a new home, laughing at the traps and the poisoned baits and the baying hounds bent on killing him.

When the annals of rodentology are written — as they surely must — this rat deserves an honoured place.

His Rasputin-like feats, redolent of the Russian mystic who likewise sneered at efforts to bump him off, were described on Thursday by New Zealand conservationists.

Their extraordinary campaign to get rid of the rat, the only rodent on a remote island, was reported in the British weekly science journal Nature.

Wildlife officers in New Zealand wage a relentless war against rats and other introduced predators that decimate populations of the kiwi and other unique native species.


In November last year, the researchers used a chocolate-baited trap to capture an adult male Norway rat on the uninhabited, forested island of Pakihi, off north-eastern New Zealand.

Seeking to find out more about how lone rats move around and survive, they took a DNA sample from the creature’s tail, fitted a radio collar and then released it on a beach on another uninhabited but rat-less island, Motuhoropapa, 30km away.

For the next four weeks, there was no problem.

The tracker collar obligingly did its job, showing that the rat traversed the entire island, eventually settling down to a home territory of about a hectare.

After that, the conservationists tried to recapture the rat, setting nearly three dozen traps, deploying two trained dogs and digging 15 tracking tunnels to tip them off to his whereabouts.

Everything, dismayingly, failed. But worse was to come.

Somehow the radio signal got turned off. Out there, unchallenged and undetectable in the gloomy green, was a long-whiskered, sharp-toothed Rattus norvegicus.

Eventually, the trail was picked up again — not on Motuhoropapa, but on the neighbouring island of Otata.

Rat faeces found on this island were tested for DNA, and proved to come from the original rat, which had swum a whole 400m across open sea to find a new home.

Short of razing Otata with napalm, the full forces of human ingenuity came into play — a grid of bait stations and tracking tunnels was set up, another five traps were cunningly buried in the ground and 20 traps were set with peanut butter as bait.

Nemesis came after 18 weeks of freedom.

Tracker dogs picked up a strong patch of rodent scent, and it was there that the conservationists uncloaked the finest weapon in their arsenal, exceptional bait for an exceptional beast: a juicy chunk of penguin.

Rasputin’s demise is science’s gain, though.

Until now, field studies have focused on the risk of high-density populations of rats, in which juveniles escape because of competition for food and territory.

This is the first research into a single rat — and shows that a lone rat may behave quite unexpectedly, taking the risk of crossing open water to a new home even when its existing habitat is full of food and without predators.

“Eliminating a single invading rat is disproportionately difficult, not only because of atypical behaviour … but also because bait can be less effective in the absence of competition for natural food resources,” says lead author James Russell, of the University of Auckland’s department of conservation. — AFP

Subscribe to the M&G

These are unprecedented times, and the role of media to tell and record the story of South Africa as it develops is more important than ever.

The Mail & Guardian is a proud news publisher with roots stretching back 35 years, and we’ve survived right from day one thanks to the support of readers who value fiercely independent journalism that is beholden to no-one. To help us continue for another 35 future years with the same proud values, please consider taking out a subscription.

Related stories

France will test flying taxis from next year, say operators

A drone-like, fully-electric vertical take-off and landing vehicle (VTOL) dubbed VoloCity, produced by German company Volocopter, was chosen for the innovative trial with flying taxis in a peri-urban area

Trial opens over Charlie Hebdo terror attacks that stunned France

14 people accused of helping jihadist gunmen storm the French satirical weekly Charlie Hebdo and a Jewish supermarket went on trial on Wednesday, five years after three days of terror sent shock waves through France

Time is not on our side in Libya

Simmering tensions could see the country partitioned between east and west

Paris throws off mask to party like the virus never was

Social distancing and face masks were largely forgotten as thousands of French people danced and partied well into Monday in the first big blow out since the coronavirus lockdown

The statue of Louis XVI should remain forever handless

A statue of the French king in Louisville, Kentucky was damaged during the protests against police killings. It should not be repaired

Rwanda: Capturing a genocide financier

A Kenyan investigative journalist reflects on the capture of a genocidaire in Paris after 26 years on the run and its significance to the families of the victims left in his wake
Advertising

Subscribers only

SAA bailout raises more questions

As the government continues to grapple with the troubles facing the airline, it would do well to keep on eye on the impending Denel implosion

ANC’s rogue deployees revealed

Despite 6 300 ANC cadres working in government, the party’s integrity committee has done little to deal with its accused members

More top stories

Hawks swoop down with more arrests in R1.4-billion corruption blitz

The spate of arrests for corruption continues apace in Gauteng and the Eastern Cape.

Catholic NGO boss accused of racism and abuse in Sudan

The aid worker allegedly called his security guard a ‘slave’

Agrizzi too ill to be treated at Bara?

The alleged crook’s “health emergency” — if that is what it is — shows up the flaws, either in our health system or in our leadership as a whole

SANDF hid R200m expenditure on ‘Covid’ drug it can’t use

Military health officials are puzzled by the defence department importing a drug that has not been approved for treating coronavirus symptoms from Cuba
Advertising

press releases

Loading latest Press Releases…

The best local and international journalism

handpicked and in your inbox every weekday