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WIlliams and Dodd paludosa, and the Everglades kite, Rostrhamus sociabilis, whose only food is the snail. Fogarty and Albury (1967) found apple snails composed 56.8 percent by volume of the stomach contents of 36 alligators in Broward County, Florida, and Martin and Hight (unpub. ms.) reported that 73 percent of the food items of alligators at the Loxahatchee National Wildlife Refuge Everglade kite management area consisted of apple snails. Such a relationship is of concern because of the extremely precarious status of the endangered kite. As with the alligator, surprisingly little is known of the role of other crocodilians in wetlands habitats. One series of studies in the Amazon showed that resident crocodiles, Melanosuchus niger and Caiman crocodilus, play a vital role in nutrient cycling in an en- vironment poor in nutrients and electrolytes (Fittkau, 1970, 1973). The species feed on numerous types of prey, primarily fish, and move into areas such as mouth-lakes of Amazonian rivers which are nutrient poor. Feces and scraps of the crocodiles form an allochthonous basis for primary production and serve as the foundation for a food chain which in turn benefits fish production. In some parts of the Amazonian drainage, removal of crocodilians - a practice initially thought to increase fish production by reducing predation -has caused a sharp decline in numbers of fishes, thus adversely impacting the human population which relied on fishing. Whether crocodiles play a similar function in other ecosystems is unknown, although Harper (1930) notes that in the Okefenokee Swamp, fishermen relate fishing success to the number of alligators nearby. The more alligators there are, the better the fishing. The Everglades of southern Florida apparently play a vital role in the ecology and biotic success of the American crocodile, Crocodylus acutus. The crocodile once ranged through southern Florida from Palm Beach County on the Atlantic coast through the Keys, with occasional individuals along the Florida Gulf Coast (LeBuff, 1957; Odgen, 1978). As many as 2,000 animals may have inhabited the region although an exact esti- mate is difficult to obtain because of lack of reliable historical data. Presently, the dis- tribution of the species is centered in upper Florida Bay and around Key Largo, with numbers estimated between 100 and 400, including an estimated 20-25 breeding females (Ogden, 1978). Reasons for the decline of crocodiles have been documented in tyre; scientific and popular literatures (Horan, 1977; Lang, 1975; Ogden, 1978). Tlie decline involved a com- bination of harrassment and killing by humans through such means as shooting, trapping, disturbance of individuals especially during nesting activities, road kills, and direct habitat destruction. Although the American crocodile cannot be considered a strictly estuarine or marine species, it does frequent environments which may have a high salinity content. The salinity question is extremely important to young crocodiles. When hatchlings emerge from the nest and enter the water, they cannot tolerate salty water because they initially have no special salt excreting mechanisms to survive hyperosmotic conditions. On the other hand, if young crocodiles complete their juvenile period of life entirely in fresh water, they never develop the physiological capabilities to tolerate excess salts found in the habitats frequented by the adults. Man has altered the salinity content of the crocodile's habitat through drainage and channelization, which has reduced the flow of fresh water into Florida Bay. Instead of a gradual rise in salinity with accompanying gradual adaptation as the crocodiles mature, the juveniles face an environment with high salinity to which they cannot adjust. As a result, few crocodiles survive to replace adults lost to the population and the numbers have steadily declined in some remote areas, such as in parts of Everglades National Park, 568