EFFECTS OF ECOTOURISM ON DISTRIBUTION OF WATERBIRDS IN A WILDLIFE REFUGE

Humans visiting natural areas often disturb wildlife, possibly displac ing animals from desirable habitat. To hold ecotourism at acceptable l evels refuge managers need to know which species are likely to be affe cted and which response occurs at different levels of disturbance. Dis placement of waterbirds at J. N. ''Ding'' Darling National Wildlife Re fuge, Florida (U.S.A), by specific human activities was demonstrated e xperimentally by Klein in 1993. We assessed the extent of this effect of ecotourism on the distribution of 38 species of waterbirds by surve ying birds in plots of known distance from a dike along which wildlife tours occurred. Most resident species were less sensitive to disturba nce than were migrants. Migrant ducks were most sensitive when they fi rst arrived, mid-October to mid-December usually remaining more than 8 0 m from the drive, even at low levels of human visitation. Herons egr ets, Brown Pelicans (Pelecanus occidentalis), and Anhingas (Anhinga an hinga) were most likely to remain close to areas of high human activit y. Shorebird's were displaced at intermediate distance and visitation levels. Mottled Ducks (Anas fulvigula) and several of the ardeids seem ed to include two groups differing in behavior one habituated to human s and one sensitive to disturbance. Public education and changes in ma nagement practices are needed to reduce disturbance. Guided tours and low-disturbance zones where people stay in their cars could reduce the negative effects of tourists, especially in the fall when migrants ar rive. The number of human visitors may have to be reduced or the wildl ife drive closed on certain days during the tourist season.