YELLOWKNIFE - You've probably seen them chirping along the shoreline, perched on slabs of slowly melting ice.

Or maybe you or your house has been unlucky enough to be the recipient of their stinky, white deposits.

Two seagulls perch on a slab of ice by the shoreline of the Willow Flats. Large flocks of seagulls are grouping together on the Flats and Jack Fish Lake, seeking mates and protecting each other from predators. - Guy Quenneville/NNSL photo

The time of year has come when large flocks of seagulls begin grouping together in areas all over the city, from the back lot of McDonald's restaurant to the thawing, icy shores of Jackfish Lake.

It's all part of a ritual the birds go through every year, according to Bob Bromley, a birdwatcher and former bird biologist with the territorial government.

"It's a routine they seem to follow when they arrive in the spring," said Bromley.

"They basically stage at places where there's open water, like by the power plant on Jackfish Lake, or down at Willow Flats by the Dettah road.

"They're waiting until their nesting islands have moats of water around them. Until then, they're relying on the dump and scavenging in the bush."

There are several reasons seagulls band together in large groups.

"They pretty much sit there conserving energy. Establishing mates. There's a lot of courtship behavior going on."

The large clusters also serve as a sort of safety mechanism for the birds.

"It's safety in numbers," said Lindsay Armer, a forest bird technician with the Canadian Wildlife Service.

"When they band together on the ice or in the water, it makes it harder for predators to get at them. If one bird sends out an alarm call, the whole flock will fly off."

Two years ago, Yellowknifers were plunged right into a scene from Alfred Hitchcock's thriller "The Birds," when seagulls began to flock over downtown Yellowknife.

Residents worried about another such incident need not be concerned, said Armer.

"In that case, there was a really bad cold snap that year, and the birds were stuck here. There was no open water because it was frozen and it was just too cold for them. So they were focused on downtown because the downtown provides a lot of shelter."

What people should be worried about is the effect that climate change is having on the habitat of seagulls, other birds and animals in general, said Bromley.

"I'm seeing changes in the birds and their habits," he said. "Some of the things I noticed was the spring melt happening earlier and earlier very year, and fall freeze up happening later.

"If their habitat becomes any more unsuitable, they'll have to move further North."