The New York City borough of the Bronx is one of the most densely populated places in the United States, but is home to a wide range of wildlife. The borough has a land area of 42 sq mi (110 km2), of which 24 percent is parkland. Most of the open area (Van Cortlandt Park, Woodlawn Cemetery, Bronx Park, and Pelham Bay Park) is in the northern section of the borough, adjacent to Westchester County, allowing easy migration of animals from the mainland. The tree canopy of the Bronx cover 25% of the land area, hosting a wide range of avian species.