The Cape Sable seaside sparrow (Ammodramus maritimus mirabilis) is a subspecies of seaside sparrow endemic to southern Florida. The largest populations are found in Taylor Slough in Everglades National Park and in the Big Cypress Swamp. The species is considered endangered due to habitat loss from vegetation changes, fire, development, alteration of water flow, and hurricanes. Cape Sable seaside sparrows are about 13 centimeters (5 inches) long.