No room for rats in Alberta

The Canadian province of Alberta has successfully defended a line of longitude against invading rats since the 1950s.

The programme demonstrates it’s possible to keep an area about three times the size of New Zealand essentially rat-free.

Norway rats are not native to North America but were introduced to the east coast about 1775.

By the 1920s, the rats had spread westward to the province of Saskatchewan and were moving towards Alberta at about 24 kilometres a year.

When they crossed the AlbertaSaskatchewan border in 1950, officials created a programme to stop their spread. Local authorities were required to exterminate those few rats already in the province and kill all that came in subsequent years. More than 65 years later they’re still working, mostly with toxins.

Alberta has many natural advantages when it comes to rats. Long, cold winters suppress rat numbers. Their spread in warmer months is stopped by the tall Rocky Mountains along the west border, ‘‘badlands’’ along the south border with the US, and boreal forests in the north. It is landlocked.

The vulnerability is the largely rural border with southern Saskatchewan, which is a manmade line on a map running northsouth. Every building in a rat control zone 29km deep and 600km long is inspected annually. Farmers in the zone are encouraged to maintain traps or call publicly funded exterminators if an infestation is detected.

A province-wide public education campaign motivates Albertans to be vigilant about rats and report sightings. It’s said Albertans are proud to be free of rats. Keeping them as pets is illegal.

When rats inevitably arrive by plane, train and truck, they are detected and killed, Alberta officials maintain. Most that arrive are singletons that don’t breed, they say.

Of course, there are sceptics especially on the internet who say rat-free Alberta is impossible.

But it’s also possible to see in Alberta New Zealand’s future once a pest species is eliminated from an area: plenty of public education, official vigilance and extermination teams that arrive commando-style when an infestation is detected.

A province-wide public education campaign motivates Albertans to be vigilant about rats.