SGin Xaana Sdiihltl’lxa: Night Birds Returning
Ancient Murrelets on the water
© Parks Canada / C. Bergman
Seabirds at risk
Ancient Murrelets (or “night bird” as translated from the Haida language), a species at risk in Canada, are being devastated by invasive rats. More than half of the world population of these seabirds breed on remote islands in Gwaii Haanas National Park Reserve, National Marine Conservation Area Reserve, and Haida Heritage Site.
Ancient Murrelet chick
© Laskeek Bay Conservation Society / Jake Pattison
Ancient murrelets come and go from small islands by night during breeding season and spend the rest of their time on the water. Burrowed under the forest floor, the tiny chicks hatch and within days scuttle through the night-shaded undergrowth as their parents call to them from the sea. These seabirds also once played an important role in the diet of the Haida people and the colonies were once prime food gathering places.
Devastated by Rats
Black rats, like this one, were abundant on islands
© Parks Canada / Carita Bergman
The birds have long since abandoned many rat-infested islands. Rats, first introduced to Haida Gwaii with the advent of maritime shipping in the late 1700s, are known to occur on at least 18 islands throughout the archipelago and have had a devastating effect on several seabird colonies.
Island Conservation, Coastal Conservation and Parks Canada are working together © Parks Canada / Andrew Wright
In 2011, Parks Canada, the Haida Nation, Island Conservation and Coastal Conservation implemented a ground-based eradication of invasive Norway rats from Arichika and Bischof Islands, once home to significant ancient murrelet colonies. This work was supported by Parks Canada’s Action-on-the-Ground program which funds ecological restoration across Canada’s national parks and by the US Coast Guard’s Oil Spill Liability Trust Fund – a fund set up to offset the damage done to seabirds by a sunken oil tanker, the S.S. Jacob Lukenbach, which went down in 1953 off the coast of California.
The Bischof Islands with Lyell Island in the background
© Parks Canada / Andrew Wright
- Field crews implemented baiting operations from August 1 to October 3, 2011 setting bait in the specialized stations, and removing rat carcasses on Bischof and Arichika Islands.
- No evidence of rats was found at the end of the field season in November 2011 or at start-up Spring 2012, but monitoring must continue until September 2013 before the islands can be declared rat-free.
- Scientists managed for the possibility that other species could have been affected by the eradication, and reported very few impacts on other species and no population-level impacts.
- Similar ecological restoration work is being planned for nearby larger islands, Murchison and Faraday in 2013.
Ongoing monitoring activities continue
© Parks Canada / Andrew Wright
Automated acoustic listening devices have been deployed on these islands and on unaffected islands to measure seabird response to the eradication. Scientists will study the frequency and distribution of the birds’ calls to gauge project success, as well as monitor a number of other ecosystem responses. In coming years, restoration techniques including the construction of artificial nesting burrows may be employed to encourage the birds to re-colonize.