Most polluted bird on record discovered in Vancouver

Coopers hawk

Last week, Vancouver was dubbed the unhappiest city in Canada.

And now, it has a new unflattering title to add to its Welcome sign: home of the most polluted bird on record.

A team of Canadian scientists was analyzing liver samples of injured or dead birds of prey in Vancouver when they came across a shocking discovery. One of the birds, a Cooper’s hawk, contained 196 parts per billion of polybrominated diphenyl eithers (PBDEs), an amount that was radically higher than any other bird tested.

Fifteen other Cooper’s hawks that were examined averaged around 18,730 parts per billion, ten times less than the most polluted bird. Birds tested in electronic waste sites in China also registered lower.

PBDEs are a group of chemicals that work as flame retardants. Although PBDEs have been banned since the 2000s in Canada and the United States, they were widely used in electronics like computers, televisions, and stereos, as well as cars, carpets and furniture. As old televisions and desktop computers clutter landfills, these chemicals are slowly leaking out and contaminating the environment.

The most polluted bird, however, did not die from direct exposure to PBDEs. It’s likely that the PBDEs affected the hawk’s thyroid gland, which in turn affected the bird’s size and behaviour.

These new findings were published in the journal Science of the Total Environment.

“Many animals, including coyotes, eagles, and hawks benefit from the excess food in our cities. A downside is the high levels of pollution,” says Kyle Elliott, one of the authors of the study and professor at McGill University, in a press release.

For example, Elliott notes that starlings, which are a favourite prey of hawks, were much more likely likely to suffer from high levels of PBDEs if it resided near a landfill site compared to elsewhere in Vancouver.

“We were surprised to see such high levels of contaminants in what I think of as a ‘green’ city,” Elliott said.

“We can only hope that because many forms of PBDEs have now been banned and the levels of these contaminants are rapidly disappearing from herons and cormorants in Vancouver, the same will be true for other bird species.”