Police found the man badly wounded by a cassowary when they were called to his property, where the victim kept exotic animals, on Friday.
Cassowaries are known as the “world’s most dangerous bird”, according to San Diego Zoo.
Alachua County Sheriff Department said the man was probably injured by the bird’s 4-inch, dagger-like claws.
Police are investigating the incident but say initial information suggests it was a “tragic accident”.
The victim, named as Marvin Hajos, was taken to hospital by paramedics, where he later died from his injuries.
He was reportedly breeding the birds, which are native to Australia and New Guinea.
“It looks like it was accidental,” deputy chief Jeff Taylor told the Gainesville Sun newspaper.
“My understanding is that the gentleman was in the vicinity of the bird and at some point fell. When he fell, he was attacked.”
Police added that the cassowary involved in the attack “remains secured on private property at this time.”
A woman who identified herself as the victim’s partner told the Gainesville Sun that he had died “doing what he loved” but chose not to make any further statement.
Cassowaries are similar to emus and are among the largest bird species in the world, weighing up to 60kg and reaching up to 6ft in height.
San Diego Zoo said cassowaries “can slice open any predator or potential threat with a single swift kick”, due to their long claws.
The birds are not traditionally raised in the US but are sought after by collectors.
The Florida Fish and Wildlife Conservation Commission lists the cassowary as Class II wildlife which can “pose a danger to people” and require a permit for ownership.
Agencies contributed to this report