Who's that sassy bird photobombing a London traffic webcam? A deeper look.

A traffic webcam in London has a popular visitor.

Transport for London -- the city agency responsible for overseeing public transit in the sprawling metropolis -- has 177 live cameras keeping tabs on traffic. A sassy looking bird has been photobombing one of the cams, just above the Blackwall Tunnel (which runs under the River Thames).

Over 2 million people have taken a look at the transit agency's most recent twitter posting of the white-headed bird, posted on April 30. Who is this attention-seeking creature?

Bird expert Kenn Kaufman had no trouble identifying the animal, a type of gull (there are some 50 species of gull).

"The bird is an adult Herring Gull, and it's an impressive species -- smart, tough, adaptable, able to make a living in a wide variety of surroundings," said Kaufman. "There are lots of Herring Gulls around London at all seasons, including right in the middle of the city, so it's not surprising for one to show up on a traffic cam."

This Tweet is currently unavailable. It might be loading or has been removed.

The industrious Herring Gulls "seem to be increasing its presence in towns and cities," added Gehan de Silva Wijeyeratne, chair of the London Bird Club. He noted that the species often nests on roofs around London and travels to other neighboring European countries.

A different population of Herring Gull (some ornithologists think different species) inhabits the North American continent too, also finding a means of survival in our heavily-trafficked urban lands.

Gulls, present on every continent, are certainly robust species overall, capable of making a living almost anywhere. They now thrive on the former super-maximum security prison that is Alcatraz Island, and feast upon the pink salmon leftovers discarded by Alaska's famous bear cam bears.

Gulls are often called "seagulls," though no such animal exists. Kaufman doesn't mind the popular name, but notes that the term doesn't describe any particular species. In fact, most gulls don't spend much time out at sea. Many are found inland, like London's now-famous Herring gull.

"You can see many more gulls in Kansas than you ever will out in the middle of the ocean," Kaufman said.