J. N. “Ding” Darling National Wildlife Refuge
Description: The J. N. “Ding” Darling National Wildlife Refuge is located on northern Sanibel Island in LeeCounty. Sanibel Island is a barrier island fringed with mangrove trees and shallow bays on the north and white sandy beaches along the south. The refuge consists of over 6,300 acres of several habitat types: estuarine habitat consisting of open water, sea grass beds, mud flats and mangrove islands; interior freshwater habitats consisting of open water ponds, spartina swales and west Indian hardwood hammocks/ridges. Approximately 2,800 acres of the refuge are federally designated as Wilderness Area. Type 1 habitat is located at the two brackish water impoundments totaling 800 acres. Type 2 habitat occurs along the sandy beaches of southern Sanibel Island.
Sanibel Island can be accessed by vehicle or boat. The most popular place to view wildlife on the refuge is Wildlife Drive, a five-mile, one-way, unpaved road that leads through the heart of a mangrove forest. Wildlife Drive can be accessed via vehicle, guided tram, bicycle, or foot. The U.S. Fish and Wildlife Service owns Darling NWR. The southern beaches of Sanibel Island are under a mixture of private and public ownerships.
A volunteer conducts surveys on the impoundments all year with the exception of summer. The most numerous species based on maximum counts from the International Shorebird Surveys for Darling NWR are: BBPL (235), WILL (155), REKN (30), SBDO (800) and DUNL (88). The most numerous species based on maximum counts from the International Shorebird Surveys for Sanibel Island are: BBPL (100), WIPL (132), SEPL (98), KILL (40), GRYE (40), LEYE (75), WILL (203), RUTU (127), REKN (1000), SAND (1200), SESA (60), LESA (300), LESA (800) and DUNL (1000).
According to Bev Postmas, a volunteer monitor, the numbers of migrating shorebirds at Ding Darling NWR and the remainder of Sanibel Island have decreased over the last several years. However, some years may have substantial numbers of shorebirds.
Survey Method: Survey the impoundments when the mud flats are exposed at low tide. The impoundments are accessible by vehicle or foot via Wildlife Drive on a dike that separates the two impoundments and offers excellent visibility with a spotting scope. One may also access the impoundments by foot on South Indigo Trail, but the visibility is limited due to the mangroves that grow between the trail and the impoundments. Survey the beaches along the southern shoreline of Sanibel Island at low tide.
Selection Bias: Not applicable as all Type 1 habitat is accessible.
Measurement error: *
Measurement bias: *
Pilot Studies: None needed.
Local Contacts: Kendra Pednault-Willett, Wildlife Biologist, J.N. “Ding” Darling NWR
Claire and Bev Postmas, volunteer monitors