Each September, pushers, or guides, take gunners through the marsh on small skiffs in search of rail birds. The movement of the boat through the grasses at high tide disturbs the rail birds so they fly up and are exposed to the gunner. Some visitors came to the Delaware Bay because it offered an opportunity to take part in rail bird hunting, a sport possible in only a handful of micro-climates across the U.S. At the height of its popularity during the 1920s and 1930s, parties of well-to-do hunters came to the Delaware Bay from nearby cities in search of the elusive rail bird, arriving in the newest cars driven by chauffeurs. Pushers were both African American and white. Today the rail birds' habitat is threatened by the loss of wild rice, a key part of the birds' diet, because of the inundation of invasive phragmites and flooding.