Wild Animals That Thrive in Cities

Some sulfur-crested cockatoos around Sydney learned to flip the lids of household trash bins. The trick spread between neighboring suburbs, and birds in different places developed slightly different ways to handle the lid. The spread gave researchers a way to watch a new foraging habit pass between birds.

Singapore’s smooth-coated otters use canals, reservoirs and ponds. A family group took up residence in Bishan–Ang Mo Kio Park after a stretch of concrete canal was turned into a river with vegetated banks. At the Botanic Gardens, researchers also recorded otters raising pups in artificial ponds away from the main waterways.

A tall building puts a peregrine’s nest above the street much as a cliff ledge would. In Indianapolis, peregrines use buildings and find plenty to hunt nearby. Pigeons are on the menu, but researchers recorded more than 25 bird species taken during the nesting season alone.

A study comparing wild boar from Berlin and the surrounding countryside found that even the city animals ate mostly natural foods. Boar can make use of green space within a big city, and their habit of rooting for food can also leave lawns and gardens torn up.

Puerto Rican crested anole In three Puerto Rican municipalities, urban anoles perched on walls and other artificial surfaces more often than their forest counterparts. The city lizards also had relatively longer limbs and more of the small scales beneath their toes. Those are differences researchers could measure in a lizard that makes its living climbing.

In Curitiba, Brazil, capybaras make use of large green spaces with water. Barigui Park combines a large lake with parkland in the middle of several neighborhoods. The city’s wildlife staff have recorded and monitored capybaras at the park, where the animals are now a familiar part of the landscape.

In the Chicago area, forest preserves and some golf courses give coyotes space within the metropolitan landscape. Tracking and camera studies show how important those stretches of green can be. A coyote living in a metropolitan area may still spend much of its time away from the most heavily built-up blocks.

Researchers followed six red fox groups in northwest Bristol, England, where roads served as useful territory boundaries. The foxes’ responses to a new object or an unfamiliar smell varied with their social status. A fox living in a neighborhood can still be cautious about something it has never seen before.

In Sendai, Japan, carrion crows were observed using traffic to crack walnuts. One pattern was to leave a nut in front of a car waiting at a signal, then retrieve the pieces after the car moved. It is a local trick that turns the timing of a city street into a way to get at a hard-to-open food.

In New York’s Central Park, squirrel counts found the densest clusters where the tree canopy was thick. The trees provide both food and shelter. Look up in a park with mature trees and you may see a gray squirrel’s nest, a bundle of twigs and leaves built high in the branches.

A warm building can give big brown bats a place to raise their young. In Fort Collins, Colorado, researchers found that maternity roosts in buildings tended to be warmer and have higher, larger openings than randomly sampled buildings. The details of a roof or wall can help explain why bats use one building and pass over another.

The red stripe behind the eye helps identify this turtle basking by a New York City pond. Red-eared sliders are native to parts of the United States farther south and west, and some entered city waterways after being released as pets. They have done well in urban ponds and lakes, where they can compete with native turtles.

Toronto’s raccoons can find a den in parts of a house, from a gap at the roofline to a chimney. Food waste also gives them something to forage for in residential areas. The same resourcefulness that helps raccoons live close to people can bring them into someone’s attic.

Rock pigeon Feral rock pigeons use window ledges and recesses under eaves the way their wild relatives use cliff ledges. A male can claim such a nook as a nest site and call from it to attract a mate. A city square provides food, but the little sheltered ledges above it help explain why pigeons stay to breed.