Which species come to mind when you think of urban birds?

For me, pigeons, sparrows, starlings and crows immediately come to mind. There have been times when I have seen some surprise birds in urban areas, such as the yellow-rumped warbler I saw while I was sitting in a downtown restaurant. There are also stories, of course, of birds such as hawks and falcons nesting in skyscrapers.

The aforementioned species, however, are perhaps the most common urban birds. A new study by scientists − based on data, research and observations from six continents and 379 cities − looks at how these species thrive in such an environment. Importantly, it also looks at how to maintain as much biodiversity as possible in urban areas. The study was published in the journal Nature Communications.

One takeaway seems rather obvious in that birds that thrive in urban ecosystems eat a variety of foods. I’ve seen house sparrows begging for French fries at fast-food restaurants. I’ve seen crows flying with pizza crust in their bills. Starlings will eat whatever is offered at the feeder – seeds, suet, fruit, mealworms, whatever.

The most adaptable species are the ones that combine a varied diet with a high degree of mobility. The scientists broke down the urban critters (including birds, reptiles, beetles, bats and bees) into four foraging categories: mobile generalists, mobile specialists, central place forager and site specialists. The mobile generalists were the most adaptable and most successful. Mobile generalists will basically eat anything, anywhere. Specialists require a specific type of food or location.

Species with a specific diet tend to disappear from urban areas, and the resulting lack of biodiversity is a detriment to the ecosystem. But how do you preserve these diet specialists when the population continues to grow and cities expand? Enter “urban ecology” as a new field of study aimed at protecting and enhancing the biodiversity of urban areas.

We often think of preserving habitat as being associated with saving large swaths of land in the wilderness. Or we think of the park or nature preserve with a pond and other wetlands in the suburbs. Rarely do we think of preserving habitat as it pertains to cities. According to the study’s authors, that needs to change.

“My perspective is that preserving habitat is crucial. Ecosystems in cities are heavily transformed and managed and intact native vegetation tends to be scarce,” co-author Frank LaSorte of the Cornell Lab of Ornithology said in a release. “The more components of an ecosystem that are preserved and supported, the healthier the overall urban environment will be.”

New York City is one of the largest cities in the world. Birdwatchers, however, know that Central Park in the middle of Manhattan is one of the top birding destinations on the East Coast, especially during spring migration. It’s been many years since I’ve visited Central Park, but the number of birds there always amazes me.

Central Park is an oasis for tired birds as they work their way to their nesting grounds. The park also has a substantial breeding bird population. Similar parks dot most urban areas in the U.S. Protecting these parks, and adding new ones, goes a long way toward preserving the biodiversity, not to mention the quality of living, of these cities. This goes for the parks and green spaces in smaller cities and towns as well.