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Along an 18-mile strip of
land between the Canadian province of Alberta and its neighbor Saskatchewan,
the rat patrol keeps guard. An eight-person team, armed with poison and
shotguns, hunts daily for any sign of the rodent invaders.
The Alberta rat patrol checks
more than 3,000 farms a year, but it rarely sees an actual rat. Alberta has
4.3 million people, 255,000 square miles, and no rats—bar the stray handful
that make it into the killing zone each year. Ever since 1950, a sternly
enforced program of exclusion and extermination has kept the province
rat-free. Nowhere else in the world comes close; the only other rat-free
areas are isolated islands such as the remote British territory of South
Georgia.
Public support and education
have been key to Alberta’s success. Locals use hotlines (310-RATS or
310-FARM) to report any sign of rodents, though false alarms are common.
School programs educate kids about the telltale signs of the invaders.
Keeping pet rats is banned and can earn you a fine of almost $4,000.
Across the world every year,
mice and rats are estimated to cause nearly $20 billion in damage and wipe
out as much as a fifth of the world’s food supply. They’re not just
enthusiastic gnawers. They’re also prolific urinators, and rat pee frequently
contaminates goods. Rats are thought to have spread the Black Death in the
Middle Ages, as they do other viruses today.
Rats arrived in Canada in the
18th century, but geographical isolation kept the invaders from reaching
Alberta for a solid two centuries, until the first signs of the rodents
started to appear along the border with Saskatchewan after the end of World
War II. That’s when Alberta’s anti-rat agenda was born. It wasn’t the first
program of its kind: Public involvement in pest control boomed in the 20th
century with the spread of disease theory and the motivational push of
wartime.
In Vietnam,
for example, the creation of the Hanoi sewer system at the turn of the 20th
century saw a boom in rat numbers; in response, in 1902 the French colonial
government began paying a bounty for their carcasses—that is, until it
realized locals were breeding them to cash in on the reward. In Washington,
D.C., meanwhile, a 1917 program attempted to wipe out feral cats, with the
enthusiastic backing of the local Cat Fanciers’ Association. “They saw alley
cats as a threat to their precious kittens,” said Hayden Wetzel, a local
historian. “It was wartime, so the slogan was ‘Kill a Cat for Your Country.’”
Canadians
may not have been as enterprising as the Vietnamese or as bloodily patriotic
as the Americans, but they have been far more successful. The brown rat
(Rattus norvegicus) thrives only among human settlements, so farms and
towns became the battlefields for the fight against invasion in Alberta.
The brown rat (Rattus norvegicus)
thrives only among human settlements, so farms and towns became the battlefields
for the fight against invasion in Alberta.
World
War II propaganda set the tone for the province’s early campaign, during
which 2,000 posters were distributed across the border region. “Rats are
coming!” cautions one grayscale poster. “You can’t ignore the rat!” reads
another. “We need to be properly organized and know what to do, in order to
fight the battle successfully,” a 1954 booklet sternly warns. Mass chemical
warfare cleansed the borderlands, with some 63,000 kilograms of arsenic
powder blown across thousands of buildings.
After
1959, the volume of annual infestations was dramatically reduced, down from
500-600 a year to fewer than 200 by 1980; today, it’s a handful annually. (A
2012 infestation in the Medicine Hat landfill was a record-setter, with
nearly 150 rats eventually rooted out.) The propaganda didn’t let up: “The
only good rat is a dead rat,” reads a 1975 poster. Today, the provincial
government focuses mostly on stories placed regularly in the Canadian media
covering the success of the program, instead of the sneakiness of the rodent.
Rat control has become institutionalized, not only through regular
inspections but through a public proud of Alberta’s rat-free status and keen
on maintaining it. The whole program currently costs just about $380,000 a
year—most of the money is spent on exterminators’ salaries—but saves
Alberta’s farmers millions.
Across the Pacific, another
former colonial outpost is struggling with European invaders, at far greater
cost.
Alberta’s
success might be imitable, but other countries lack the geographical
advantages that confine the rat to a narrow access corridor. New Zealand has
had a rodent problem ever since the Maori brought the kiore, or Polynesian
rat, with them in canoes in the 13th century. But the first R.
norvegicus—far
larger and meaner than its Polynesian cousin—crawled off a ship in the 1770s
and discovered a land of plenty. To the rat, the eggs of New Zealand’s bird
life, which had never adapted to murine predators, offered an all-you-can-eat
buffet. Rats and other nonnative species, such as possums and stoats,
slaughter approximately 25 million birds a year. The slaughter, plus rats’
usual damage to crops, cost the economy $2.3 billion annually, according to
the government.
Alberta
government rat posters. (Provincial Archives of Alberta, PA1579.2/Calgary Herald, a
division of Postmedia Network Inc.” )
New
Zealand has battled to keep as much of the country rat-free as possible,
especially its isolated islands that preserve taonga (“treasures”
in Maori), unique flora and fauna such as the kiwi and the kakapo parrot. But
rats are master swimmers and hiders; one test subject, Razza the rat, evaded
capture for more than four months, becoming the unlikely hero of a children’s
book. All it takes to defeat a mass extermination campaign is a single
pregnant survivor.
That’s
why the government has given up on half-measures; instead, a hugely ambitious
program launched in 2016, Predator Free New Zealand, envisages wiping out not
only rats but stoats and possums by 2050. It’s an expensive effort. The pilot
scheme—conducted on two inhabited islands, covering almost 15 square
miles—cost about $3 million. The plan is to assault the rats (and other
invasive predators) on all fronts, using drones to blitz them from above and
map their locations, customized poisons and traps on the ground, and perhaps
(although it’s highly controversial) genetic modification to permanently
alter breeding habits.
Part
of the work, said the conservation biologist James Russell, a key mover in
the program, must focus on public education and support. Drawing on models
such as the Alberta strategy has helped create an informed and engaged
public, with more than 1,000 volunteer groups involved in wildlife
protection. In Canada, the program built on wartime language, engaging a
public that was already eager to come together to fight an alien menace and
focusing on the danger to human civilization and industry. In New Zealand, it
instead draws on the love of local wildlife and the natural world. “New
Zealanders are in touch with nature,” Russell said, “and they play a huge
role in protection efforts—they’re often the first to report new rat
sightings to the hotlines.”
Climate
change is
giving a new urgency to the project. A record-hot summer created the breeding
conditions for a rat explosion. Hotter temperatures let rats survive the
winter better, Russell said, and to reach higher densities in the summer,
pushing greater numbers into areas such as southern New Zealand, where the
threat was once relatively low.
Beyond
rats, a hotter world is making the threat of invaders greater across the
board. As climate shifts, threatening flora and fauna are moving with it,
even into once inaccessible areas. In the United Kingdom, a degree or two of
warming could create a welcome home for the ecology-wrecking Argentine ant.
Australia’s already stressed native species, including pygmy possums and
wombats, are especially vulnerable to invaders such as foxes. Other
governments are already experimenting with apps and hotlines to report
invasive species. But as the planet warms, the need for far more extensive
programs of education and eradication like Alberta’s will only grow.
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A poster released by the Alberta Department of Public Health circa 1948. (A17202b/Provincial Archives of Alberta)
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