As the cooler temperatures encourage us to relax outdoors this autumn, the falling leaves and changes in daylight signal to hummingbirds that they should begin their migration southward.

Worldwide, there are over 300 species of hummingbirds, several of which can be found in Alabama. This includes the ruby-throated, rufous, Allen’s, black-chinned, and calliope species.

The ruby-throated hummingbird is the most common species, as it uses Alabama as its breeding ground during the spring and summer.

The older ruby-throated hummingbirds start the fall migration in late August, with the younger birds following in October and November, according to a new research study by Theodore Zenzal at the University of Southern Mississippi. Zenzal and colleagues also discovered that ruby-throated hummingbirds can travel over 1,200 miles without a break, as they migrate from the eastern United States to Mexico and Central America, where they will spend the winter. The ruby-throated hummingbird does not live or travel in flocks, but makes this journey individually.

According to a fact sheet developed by Martha and Bob Sargent, founders of the Hummer/Bird Study Group, a  ruby-throated hummingbird’s wings beat between 40 and 80 times per second. When resting, the heart rate is about 250 beats per minute compared to 1,200 beats per minute when feeding. Because they have such high metabolic rates, they must feed throughout their migration, about four times an hour. While they typically weigh about three grams (the weight of three standard sized paper clips), ruby-throated hummingbirds will attempt to double their body weight prior to migration.

The ruby-throated hummingbird’s normal flight speed is about 30 mph and 50 mph when escaping predators. (Image courtesy of Vickie Harney.

Male immature type ruby-throated hummingbird. (Photo courtesy of Tom Gordon and Vickie Harney)

Hummingbird feeder at the Aldridge Botanical Gardens in Hoover. (contributed)

Female immature type ruby-throated hummingbird. (Photo courtesy of Tom Gordon and Vickie Harney.)

The Sargents, of Trussville, initiated some of the earliest hummingbird research in the South and were instrumental in the success of the bird banding program at Fort Morgan. They recommend waiting to take down a hummingbird feeder until two weeks have passed since you’ve seen your last hummingbird of the year, or two weeks after the fluid level in the feeder has ceased to go down.

Just be sure that the feeder is regularly cleaned and the solution is fresh.

While you may not see hummingbirds with the frequency of the spring and summer, there are still hummingbirds headed south, with thousands of miles to travel, that would welcome and appreciate your help during their long journey.

Historical note

In 1987, Martha and Bob Sargent started banding hummingbirds in an effort to develop a knowledge base about the species and their migration. According to a 2012 interview with AL.com, Bob Sargent said, “We’ll band a bird in our yard. He’ll migrate, go to South America, survive, and the next fall, he’ll come back to our yard. I can go back and look at the data from when we banded each one of those birds. They are passing through our yard within a day or two either side of the exact date when we captured them in the yard before. That’s over the course of nine years. Amazing.”

Two years later, the Sargents began working with and training volunteers in banding. During their banding career they trained over 100 banders in the eastern U.S.