By The Chronicle Staff

As summer begins to give way to fall, one of the smallest visitors to Logan County backyards is preparing for one of the most remarkable journeys in the bird world.

The ruby-throated hummingbird (Archilochus colubris) may weigh little more than a penny, but each year the tiny bird undertakes a migration stretching hundreds — and for some individuals, thousands — of miles between its North American breeding grounds and wintering areas to the south.

Despite their size, hummingbirds are powerful and highly specialized fliers.

Adults generally measure about 2.8 to 3.5 inches long and have a wingspan of approximately 3 to 4.3 inches. They weigh only about 3 to 3.5 grams, or roughly one-tenth of an ounce.

Their wings can beat 50 to 53 times each second during normal flight. Their unique wing movement allows them to hover almost motionless in front of a flower, move quickly from side to side and even fly backward.

Both male and female ruby-throated hummingbirds have metallic green feathers across the back and crown. The adult male is easily recognized by the brilliant iridescent ruby-red throat patch that gives the species its name. Females lack this feature.

A remarkable migration

Their small size makes Ruby-throated hummingbirds’ long-distance travels particularly impressive. They spend the breeding season across much of the eastern and central United States and into Canada, while their wintering range includes Mexico, Central America, and areas along the Gulf Coast.

For many ruby-throated hummingbirds, migration includes an extraordinary challenge: Crossing the Gulf of Mexico.

Some make a nonstop flight of approximately 500 miles across open water.

Depending on weather conditions, the journey can take roughly 18 to 24 hours, leaving the birds with no place to land, rest or feed until they reach the opposite shore.

To prepare for this trek, hummingbirds dramatically increase their food intake and can nearly double their body fat. Those energy reserves become the fuel that allows them to complete the long flight.

More than nectar

Hummingbirds are closely associated with flowers, but nectar is only part of their diet.

They are especially attracted to tubular flowers, including many red and orange varieties. Their long bills and specialized tongues allow them to reach nectar deep inside flowers that may be difficult for other animals to access.

The birds also readily visit backyard feeders containing sugar water. but hummingbirds also require protein and other nutrients. They obtain those by eating tiny insects and spiders.

Their dependence on both flowers and insects means gardens containing a variety of flowering plants can provide valuable habitat.

Backyard visitors on the move

Late summer and early fall can be an especially active period for people who maintain hummingbird feeders.

As migration begins, birds need enormous amounts of energy, and feeders can provide a convenient source of calories along their route. Migrating hummingbirds may stop briefly to replenish their energy before continuing south.

The old belief that leaving a feeder outside in fall will prevent hummingbirds from migrating is a misconception. Migration is driven largely by instinct and changes in daylight rather than the availability of a backyard feeder. Birds will continue their journey when they are ready.

Feeders should be kept clean and the sugar-water solution changed regularly, particularly during warm weather when it can spoil quickly. Plain white granulated sugar and water are sufficient; red dye is unnecessary. ■