The county commissioners' vote to amend development rules Thursday eases the way for 80 wind turbines on 16,000 acres of sugar cane land near Belle Glade.
The Sierra Club and Audubon Society warned rotating blades would threaten migrating birds such as eagles, wood storks and the Everglades snail kite, and their lights would disorient them, the South Florida Sun Sentinel reported.
"They will be drawn (to the towers), they will circle these and they will die," said Drew Martin of the Sierra Club.
The wind arms can spin at almost 200 mph, with each tower expected to generate enough energy to power 400 homes.
The U.S. Fish and Wildlife Service wrote to Wind Capital Group July 1, urging more study of potential wildlife threats.
"Collisions with turbine blades are often fatal, and usually resulting in the animal being effectively eliminated from the breeding population," the agency said.
George Gentile, representing Wind Capital, said a yearlong review would determine the risk to wildlife.