NYC parks are good resources for migrating birds

11.03.11

A recent study by scientists at the Wildlife Conservation Society has found that urban parks are comparable stopover landscapes to non-urban sites in providing refueling grounds for migrating birds. Researchers examined migrant stopover biology in Prospect Park, Inwood Park and Bronx Park to better understand how birds use city parks during migration. The non-urban sites selected for the study were Marshlands Conservancy and Ward Pound Ridge Reservation in Westchester County, which have similar forest stand composition to the urban parks but vast differences in nearby human population density. The study measured mass gain and triglyceride levels in surveyed birds and found these levels comparable across sites. Chad L. Seewagen, Ph.D, who prepared the Project’s report, has three ideas as to why urban stopovers are, contrary to expectation, as satisfactory as their non-urban counterparts:

• Though parks are fragmented and surrounded by heavy development in NYC, it is possible that they retain enough of the properties of larger, intact forests to offer migratory birds satisfactory refueling grounds.
• It might be that these birds are so flexible in their requirements during migration that they are able to exploit even the most unfamiliar habitats.
• Seewagen hypothesizes that the heat island effects of urban environments actually improve refueling conditions: warmer air in cities allows the birds’ terrestrial grub to thrive and survive further into the autumn season.

The report cautions against taking its findings to indicate that migratory habitat is not impacted by urbanization. It also notes that observing a dense presence of migratory birds in a certain area does not necessarily prove it to be a satisfactory refueling point, only an available one.

Tags: New York City, parks, research, wildlife