ABSTRACT
The West Indian manatee inhabits coastal areas, estuaries, and associated rivers in the New World Atlantic from the southeastern US to central Brazil. Most sirenian surveys to date have been conducted in the US or Australia. Except for the extreme southwestern part of the state where warm water sources are unavailable, most Florida manatees winter at natural artesian springs or warm-water effluents from power plants and factories. Aerial surveys are more effective than surface censuses for counting manatees because larger areas can be surveyed and viewing angle is superior. Unless relative positions of all surfacing manatees can be determined, estimates of the number of animals at a location may vary widely due to recounts of the same individuals. Mud trails or surface wakes may draw attention to animals some distance away. Weather and sighting conditions are important considerations when planning flights.
