We examined patterns of avian diversity in a maritime ecosystem at Orient Beach State Park on the North Fork of Long Island, NY. We compared avian diversity in beach, saltmarsh, shrub, a Juniperus virginiana (Eastern Redcedar) maritime forest, and an interior hardwood forest at nearby Mashomack Preserve. Maritime forest was highest in bird species richness followed by saltmarsh, interior forest, shrub, and beach. Habitat variables best explaining avian species richness were sand cover, vegetation cover, visibility, and height of nearest vegetation. The peninsular shape of the maritime forest supported greater edge habitat compared to the interior forest, encouraging greater avian diversity. This study provides baseline information for the conservation of a rare maritime ecosystem.