Understanding hummingbirds in a Florida winter
The Ruby-throated Hummingbird (RTHU) is one of our best known and highly anticipated migrants but even after the vast majority of RTHUs have migrated across the Gulf of Mexico each fall, a few remain on the peninsula for the entire winter. This pattern of overwintering has become much better understood in recent decades due to the work of hummingbird banding networks. Banders are trained to safely trap a bird in order to obtain critical biological metrics including species identification, sex, age, wing and tail length measurements, and weight. Coordination between banders and a community of better informed feeder enthusiasts has helped the shatter the myth that hummingbirds remain on the peninsula because feeders are left out too long.
The graph below shows the historical annual frequencies of RTHU observations in Alachua County. Note that it never really goes fully to zero. There has always been some degree of overwintering in Florida. People who leave feeders out all winter are only more likely to see a hummingbird that would be overwintering anyway.
Banding and more careful methods of identifying hummingbirds such as documentation with photography has also shown that the Rufous Hummingbird (RUHU) may be the more common overwintering hummingbird in Florida or anywhere in the Eastern United States. People often express concern over a hummingbird's ability to make it through the colder winter but RUHU endures harsher conditions in its breeding range during breeding season than it does in Florida during the winter.