5,800 years of droppings: Unique approach yields first long-term seabird trend data

Scientists have sifted through nearly 6,000 years of seabird droppings to get what they say could be the first long-term reading on how their numbers are affected by humans.

A paper published today describes how scientists drilled down through 5,800 years of lake sediments on an island off Canada’s East Coast.

Those sediments — mostly the droppings of thousands of seabirds that have nested there for millennia — were used to estimate bird populations over the centuries. 

While there have been big swings, metres and metres of bird guano suggest that the biggest and most permanent drop came when humans settled on nearby islands in the 19th century. 

The paper suggests that today’s populations of Leach’s storm petrel on the island just off St. Pierre and Miquelon are only about 16 per cent of the historical norm.

Co-author John Smol of Queen’s University in Kingston, Ont., says the technique could be used to establish long-term populations for other species, one of the main challenges in conservation.    

This report by The Canadian Press was first published Dec. 7, 2020. 

The Canadian Press