The Current

Parks Canada calls for rat tails and ears to trace rodent's move to Haida Gwaii

Rats are the scourge of the Haida Gwaii archipelago in B.C., decimating seabird population. After efforts to eradicate the rodents, scientists are using recovered rat corpses to investigate how they travel and how they may survive us all.
Parks Canada are asking Prince Rupert residents to bring in rat tails and ears so researchers can determine where the rodents that are infesting Haida Gwaii are coming from. (Samrang Pring/Reuters)

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For centuries, rats have been the scourge of the Haida Gwaii archipelago off the northern coast of B.C.

The rodents aren't native to the island but are believed to have come ashore when boats from Europe visited the islands. And the rats have been wreaking havoc with native populations ever since.   

Parks Canada has been working to eradicate the invasive rats for years, but their recent efforts take things to another level — asking residents of Prince Rupert, B.C., to bring them the ears and tails of rats.

Tyler Peet, a resource conservation manager for Parks Canada at Gwaii Haanas National Park Reserve, says a couple years ago, rats were successfully eradicated from a number of islands. 

The project was to eliminate the rats from predating on seabird nest eggs, the chicks and even some nesting adults.

"So by having successfully gotten rid of those, we're now casting a bit of a further net to try and learn more about the genetic landscape in, and around, Gwaii Haanas," Peet tells The Current's Friday host Laura Lynch. 
Rats are not native to the Haida Gwaii archipelago off the northern coast of B.C.. It's believed they came on boats from Europe centuries ago. (jans canon/flickr cc)

He says for two years the park has been trapping rats and now have 300 samples to work with.

Peet compliments "a couple of very dedicated and tolerant technicians working tirelessly here clipping two centimetre pieces of tails and ears — not a pretty sight."

He explains to Lynch that the eradication was done by "by an aerial broadcast of a tailor-made sample of rodenticide."

"So picture a helicopter with a gigantic basket that sort of swings back and forth and distributes the pellets across the landscape in a uniform way."

He hopes the message goes out and residents of Prince Rupert collect their rat bits and deliver them to 417 Second Avenue West.

UBC biology professor Michael Russello isn't surprised of the infestation in Gwaii Haanas National Park.

"If you look around the world this particular species of rat occurs on nearly every land mass around the world — the only exceptions being Antarctica, and parts of the Arctic if you get far enough north," Rusello tells Lynch.

"So this is really one of the most successful mammals in terms of spreading itself around the world."

This specific species, commonly known as the Norway Rat, doesn't actually originate in Norway but may have spread from there into other European countries.

Other nicknames are brown rat, sewer rat, city rat.

"It's the rat you commonly see in in northern cities — in subway systems, coming out of sewers, eating garbage on the street, burrowing in parks," Russello explains.

Russello who has been studying the global travel of rats says the brown rat originated in northern China or Mongolia and its earliest migrations were through East Asia and down into Southeast Asia.

He tells Lynch the rats evolved to be commensal with humans to live off of our resources.

"And so it's likely that they evolved to take advantage of human agriculture and grain storage initially, and then they spread throughout villages and towns and later cities in Asia."

When asked by Lynch if he has any positive feelings towards the rodents, Rusello finds the task difficult.

"I have trouble finding too many redeeming qualities other than their intrinsic value as part of the world's biodiversity."

Listen to the full segment at the top of this web post — including a rat expert on migration patterns and infestation.

This segment was produced by The Current's Liz Hoath, Lara O'Brien and Steph Kampf.