In an effort to eradicate rats, officials with Parks Canada have taken to the skies to drop poison pellets on a couple of islands in Haida Gwaii. 

Eighteen islands in the archipelago are now infested with invasive rats, but the offensive is focusing on two island in the Juan Perez Sound.

Laurie Wein, a program manager with Parks Canada, says the tiny pellets of rat poison are being dropped from a bucket that has been slung under a helicopter.

Wein says the rats are responsible for wiping out some sea bird populations by devouring their eggs and chicks. 

"It's a veritable buffet," she said. 

"They've all kinds of sea birds, native mammals, that they ran rough-shod."

Of particular concern is the Ancient Murrelet, a sea bird that was nearly wiped out on the islands, and conservationists hope the rat attack will correct the imbalance. 

But the effort will have to be thorough. 

"They can quickly re-establish their populations even from one remaining individual," says Wein, adding Parks Canada has taken steps to ensure other species aren't impacted.

Wein says the Norway rats were likely introduced to Haida Gwaii on logging boats 60 years ago.  

"We know that these rats arrived to these islands, probably around the 1950s, and really got established once these areas were undergoing logging. So with the movement of logging equipment between islands, it's quite likely that that's how rats got on these islands."

The aerial attack will continue until next month.  

With files from CBC's Marissa Harvey