City slicking birds may have major advantages over their country kin.

Birds who live in urban areas solve problems better than their rural counterparts and, surprisingly, have more robust immune systems, according to a new study published in the journal Behavioral Ecology.

The researchers, who work at McGill University's Bellairs Research Institute on Barbados, arrived at these conclusions by studying bullfinches on the tropical island.

Barbados' mix of urban and rural areas means the researchers could study birds that regularly mingle with humans in towns and cities, as well as birds living in remote areas.

Scientists already knew city and country birds of the same species use different survival behaviors, but this is the first time they've found clear cognitive differences between urban and rural populations.

The Barbados bullfinch, despite its name, is not a true finch — instead, the species belongs to the seedeater family. Postdlf / Wikimedia (CC BY-SA 3.0) The two groups of bullfinches were tested on their color discrimination, problem solving ability, boldness, and neophobia (the fear of the unknown). There was no difference in color discrimination and, surprisingly, city birds turned out to be more easily spooked than their rural brethren.

But the urban birds had the clear survival advantage. Finches in the city turned out to be both bolder and better at innovative problem solving, like getting access to a small jar of seeds:

The researchers assumed this extra brainpower had to come at a cost and suggested that city birds traded immune system strength for their problem solving.

The logic: Birds that live in rural areas are exposed to a greater diversity of irritants like bacteria and fungi, and as a result, their immune systems are often more robust. But in the case of the Barbados bullfinch, they found that the city finches' immunity was actually stronger than that of country finches.

It's not clear these results apply to other species of birds in other places, let alone other kinds of animals, but that could very well be the case.

"This was really surprising," researcher Jean-Nicolas Audet said in a video posted by the team. "It seems that in this case, at least, the urban birds have it all."