Key West National Wildlife Refuge / Great White Heron National Wildlife Refuge
Description: Key West National Wildlife Refuge and Great White Heron National Wildlife Refuge are located along the Lower Florida Keys in Monroe County. National Key Deer Refuge, whose headquarters are located on Big Pine Key, administers both refuges. The Great White Heron NWR consists of a 290 square mile area of water and unpopulated islands that lie on the north side of the main chain of the Lower Florida Keys, between Marathon and Key West.Key West NWR is located immediately west of Key West, FL and encompasses more than 300 square miles of open water and 2,019 acres of land on 26 islands. The area managed is overwhelmingly marine environment, including large sand flats surrounding the islands that are used extensively by foraging shorebirds. Other habitat includes low mangrove islands and sea grass and coral reef communities.
The Great White Herons NWR’s establishing authority prohibits access to most backcountry islands although some state-owned lands that are managed by the FWS allow public use during daylight hours. Two of the Key West NWR islands have portions of their beaches closed to the public. Portions of Woman Key and Boca Grande Key are posted as closed for the sensitive habitat they contain. The remainder of the beaches, including those at the Marquesas Keys, is open during daylight hours for compatible, wildlife-oriented recreational uses. U.S. Fish and Wildlife Service owns the islands, and the State of Florida owns anything below mean high water level. There are no bridges to the offshore islands, so access to most of Great White Heron NWR and all of Key West NWR is by boat only.
Thomas Wilmers conducted formal shorebird surveys on Marvin Key, located in the Great White Heron NWR, until a hurricane destroyed the key in 1998 and the key was no longer used as a roosting site for shorebirds at high tide. During the summer and winter months, Mr. Wilmers conducts turtle and wading bird surveys at Key West NWR and simultaneously conducts PIPL surveys.
Several thousands of shorebirds feed on the vast expanse of tidal flats during low tide, but the birds are spread out over several miles on the flats, which are mostly inaccessible. The location of the shorebirds during high tide is unknown, but SBDO and WILL are sometimes spotted along the mangrove roots. Mr. Wilmers will spend a total of two days to help us survey and will provide a flats boat as well as his expertise on navigating the waters, which is very difficult due to extremely low water levels and unmarked channels. According to Mr. Wilmers, five to six shorebird species use the area: BBPL, SBDO, LEYE, GRYE, WILL.
Survey Method: Boat survey at low tide when the shorebirds are feeding along the emerged flats. The area experiences four tides in 24 hours, so only a total of 4 to 5 hours would be available in a day to conduct the survey at low tide. This barely allows enough time to survey the best sites, while other sites that have substantial numbers of shorebirds will not be surveyed. The surveys will need to be conducted quickly to cover as much area as possible, so a minimum of three people will be necessary to count as many birds as possible in the short window of time available.
Selection Bias: The majority of tidal flats, which is Type 1 habitat, is inaccessible, and a thorough count of all shorebirds is extremely difficult, if not impossible.
Measurement error: *
Measurement bias: *
Pilot Studies: If possible, a survey plan should be created that would enable a more complete count of the shorebirds. If the location of the shorebirds at high tide can be determined, a survey at high tide may produce more accurate counts and reduce the overwhelming difficulty of conducting a survey at low tide. An aerial survey may be difficult due to various flying restrictions as well as species identification of shorebirds.
Local Contacts: Thomas Wilmers, Biologist, National Key Deer Refuge