Rats

Almost everywhere there is human settlement there are rats.
More than 80% of the world's islands are affected by rats.
They are notorious stowaways on ships.
There are 2 species of rat introduced to Haida Gwaii, the Norway rat and the black rat.

European Roof rats were first found on Haida Gwaii in 1919, brought with the first sailing ships.
The larger more aggressive Norwegian rat probably arrived in the 1940's and was first seen on St. James Island near the lighthouse.

Rats inhabit 19 islands of Haida Gwaii, including 7 with seabird colonies.

Since the 1950's rats and raccoons have been linked to the decline of many seabirds; ancient murrelets, Cassin's auklets, rhinocerous auklets, tufted puffins and fork-tailed and Leach's storm petrels.

In 1997 Parks Canada set up a similar program on St. James Island and later on the Bischof Islands.
The eradications appear to have been successful. It remains to be seen if they remain rat-free and how the bird populations will recover.
Right: remains of predation.