According to the American Birding Association, 947 species of birds can be found in the United States at some time in the year. This is an astonishing ten percent of the total number of bird species found in the world. Areas such as the Gulf Prairies/Marshes, Pineywoods, Eastern Deciduous forests, Great Plains, Prairie Potholes, Brushlands and Deserts provides the country with a lot of different habitats, thus allowing many types of birds to live here. During the Spring and Fall, areas such as Houston Audubon Society's Boy Scout Woods and Smith Oaks play an important role in bird migration. The Gulf of Mexico coastline and wetlands provide ducks with wintering grounds, while the prairie pothole regions in the Great Plains provide breeding grounds for ducks. For example, in Texas, birders from all over the world come to visit birding hotspots such as Big Bend National Park, High Island, World Birding Center, Aransas National Wildlife Refuge (NWR) and Santa Ana NWR.