Conservation and Management of the American Crocodile

Kushlan, James

Habitat loss has been identified as the primary cause of endangerment of the American crocodile in Florida. The distribution, growth, and survival of crocodiles has been linked to the regional hydrologic conditions, especially water levels and salinities. A goal of Biscayne Bay restoration and management is to provide more natural timing and distribution of freshwater to southern Biscayne Bay. The objectives of this project were to determine the status and habitat relation of crocodiles in southern The American crocodile is a rare and endangered species, the range of which has contracted to disjunct locations such as Hispaniola, Jamaica, Cuba, Panama, and southern Florida. In an attempt to determine what factors might be limiting population growth, an extensive collaborative research program was conducted in 1978-82 in southern Florida. Limiting factors explicitly studied included climate, hurricanes, population dispersion, nesting habitat, fertility, predation, nest chamber environment, juvenile suNivorship, artificial mortality, disturbance, and environmental contamination. No single natural factor limits the population, although in concert various factors result in low adult recruitment rates. Such natural limitations explain the natural rarity of this tropical species at the temperate limits of its range. Two artificial sources of mortality are death of adults on roads and the flooding of nests by high groundwater tables. These sources of mortality are potentially controllable by the appropriate management agencies. Active management, by such means as protection of individuals, habitat preseNation and enhancement, nest site protection, and captive breeding, is also appropriate for assuring the suNival of a rare species. The American crocodile has suNived in southern Florida in face of extensive human occupancy of parts of its former nesting habitat, demonstrating the resilience of a threatened species. This case history illustrates the efficacy of conducting research aimed at testing specific management hypotheses, the importance of considering biographical constraints limiting population status in peripheral populations, the need for active management of rare species, and the role of multiple reseNes in a conseNation and management strategy.

Conservation and Management of the American Crocodile

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