Sanibel Island - Ecology

Ecology

The island's curved shrimp-like shape forms Tarpon Bay on the north side of the island. It is linked to the mainland by the Sanibel Causeway, which runs across two small manmade islets and the Intracoastal Waterway. A short bridge links Sanibel Island to Captiva Island over Blind Pass. The Bailey-Matthews Shell Museum on Sanibel is the only museum in the world dedicated entirely to the study of shells. The Gulf-side beaches are excellent on both Sanibel and Captiva, and are world-renowned for their variety of seashells, which include coquinas, scallops, whelks, sand dollars, and many other species of both shallow-water and deeper-water mollusks, primarily bivalves and gastropods.

Sanibel Island is home to a good variety of birds, including the Roseate Spoonbill and several nesting pairs of Bald Eagles. Birds can be seen on the beaches, the causeway islands, and the reserves, including J. N. "Ding" Darling National Wildlife Refuge. Common sights include pelicans, herons, egrets, and Anhingas, as well as the more common birds like terns, sandpipers, and seagulls. There is a population of American Alligators, and a lone rare American Crocodile had been seen at the refuge as well for over 30 years, but she died in 2010 of unseasonably cold winters or old age. A memorial was set up at J.N. "Ding" Darling National Wildlife Refuge honoring "Wilma," as she was known by the residents. A new crocodile was introduced in May of 2010 when she was found on a private property and relocated to J.N. "Ding" Darling National Wildlife Refuge. Plants on the island include the native sea grape, sea oats, mangroves, and several types of palm trees. The Australian pine is an introduced species that has spread throughout the island, to some extent overpowering native vegetation and trees. Once mature, the pine blocks sunlight and drops a thick bed of pine needles that affect the soil's pH and prevents new native growth. The ground is very soft under these pines.

The local form of the marsh rice rat has been recognized in some classifications as a separate subspecies, Oryzomys palustris sanibeli.