Urban seagulls: Pests, or important indicators of environmental change?

Seagulls are often thought of as a nuisance — swarming overhead or hovering nearby, trying to score a french fry while we're just trying to enjoy a nice day at the beach.

But according to researcher Louise Blight, those flying pests are important indicators for what's going on in the local marine environment. 

Blight, an adjunct professor with the University of Victoria's School of Environmental Studies, studies seagulls in downtown Victoria, B.C., and understands why some people might not be appreciative of their presence.

 "Gulls can be noisy and annoying for sure," Blight told On the Island host Gregor Craigie.

 "I think they're pretty beautiful to watch."

In late June, chicks are just beginning to hatch, and Blight said in a few weeks downtown dwellers will be able to hear young gulls calling out to their parents.

She said it's important for humans to learn to coexist with seagulls, because urban populations are here to stay, and they offer insight into what's happening in the local environment. If the population declines, it could tell biologists that something "profound" is happening in the area in which they live.

"They're an intrinsic part of coastal life," Blight said.

Blight, who was lead author of a study on the birds in 2015 out of the University of British Columbia, said gulls historically relied on a purely marine diet, so the fact they're turning to french fries and garbage could mean that things like small fish and shellfish aren't as easy to come by as they once were. 

Heading toward land for food means they end up creating living spaces for themselves nearby, such as the roof of a condo building.

Urban environments offer flat, isolated surfaces for the gulls to nest, which Blight said are similar to their preferred nesting environments in the wild, particularly on islands. 

Seagulls in both Victoria and Vancouver seem to survive well, Blight said, and produce more offspring when living in the city. 

"One of the things that happens at natural colonies is that they're quite aggressive to each other's chicks," Blight said. "But there's generally just one disturbance that happens. It's quite likely that they have less predation in urban areas … they're harassed less by bald eagles, for example." 

In the wild, Blight said the birds tend to spread out differently than in the city, which is something researchers are keen to learn more about.