Backyard birdwatchers have spent the spring and summer amused by the antics of the ruby-throated hummingbirds. These shimmering jewel-like birds almost seem to levitate in the air as they congregate around feeders, their delicate wings beating so rapidly they’re barely visible. While their activity appears as carefree as summer itself, these birds have been in preparation for migration, an arduous task that begins in late summer.
Hummingbirds Leave Back Yards in Late Summer
The cycle of arriving in spring and leaving late summer is more than just coincidence. These birds show up, sometimes in droves, at our backyard feeders to begin preparing for their migration. They are getting ready to head south to their winter homes.
You could almost consider your feeder a resting station, like one you may stop at during a long journey in your car. These hummingbirds are literally making a pit stop to refuel so they can continue their way south for the winter months.
See also: Hummingbird Migration Patterns Explained
The weather—and the amount of fat the hummingbird has already stored—will determine how long it will remain at your backyard feeder. It’s not uncommon for this bird to spend only a week replenishing its fat reserves, but it can also remain for several weeks.
Come late summer you will begin to see the numbers of hummingbirds at your feeder diminish. If you’ve noticed movement as early as July, most likely those travelers are ruby-throated hummingbirds from the Midwest or even Canada, starting their migration in July.
How Hummingbirds Prepare for Migration
Like other cycles in a bird’s life that are triggered by changes in seasons, the migration of the ruby-throated hummingbird in the fall is prompted by the decline in the day’s length. As the days grow shorter, chemical changes occur in the hummingbird’s body, creating an overwhelming need to eat.
This frenzy of binge eating helps prepare these birds for the energy-expensive journey ahead. Each migrating bird must store enough food for this enormous trip. The hummingbird will need to increase its body weight by 25-40%.
See also: Hummingbirds Fact vs. Fiction
To understand the enormity of this feeding frenzy, think of a 178-pound man gaining 70 pounds. Not only is the amount of weight gained huge, but the bird’s capability to gain it at a rapid pace is astonishing. These minuscule birds accumulate fat and become so swollen in size that their usual quick and effortless maneuvers become more difficult.
An Orderly Departure
You might be surprised to learn that there is order as hummingbirds depart your backyard feeder for migration. Adult males are the first to leave. Adult females typically leave after all the male hummingbirds have left. Like so many occurrences in nature, there is logic behind this practice.
By leaving before both the females and immature birds, the males do not have to compete for whatever fading flowers are left. Nor will they have to compete for other dwindling food sources. This gives immature birds enough time to gain necessary fat stores before they begin their arduous migration journey south–most for the very first time. This staggered departure also allows for more food to be accessible along the migration trail.
Due to the number of birds that hatch over the summer months, the number of hummingbirds migrating at late summer will almost double the number that return in the spring. Unfortunately, the returning numbers in spring are lower due to dangers met during migration.
Making the Long Journey
Ornithologists believe the hummingbird migrates at a speed of roughly 25 miles-per-hour. Hot air balloonists claim to have seen ruby-throated hummingbirds flying south at up to five hundred feet from the ground.
The ruby-throated hummingbird’s migration appears to almost be an effortless event. These petite birds migrate 23 miles a day. However, to make that flight, it must beat its wings a startling two point seven million times. It’s a concept that is hard to imagine.
In order to do this, the hummingbird must carry the necessary fat reserves. Males can carry enough fat to fuel a flight lasting up to twenty-six hours. The female, if she’s large, will store enough fat to fly for 24 hours. During migration, they can travel from 600-640 miles.
The migration journey of the hummingbird takes place during the day, unlike many other birds that migrate to warm locations. However, when they are flying over the Gulf of Mexico, the length of the trip necessitates flying in the dark.
Risks and Dangers of Hummingbird Migration
The arduous task of migration is not without danger or risks. Strong winds and heavy rain can delay migration. Additionally, the direction of the wind plays a key role in determining how far the hummingbird will migrate. Like an airplane flying from north to south, it seems that southbound migration is most substantial when birds can catch a good tailwind.
Unfortunately, hummingbirds that meet up with a tropical storm while flying over water typically don’t survive. Strong headwinds can be deadly for the migrating hummingbird. 20 mile-per-hour winds are enough to push them backward, causing them to lose fat stores and delay migration.
Backyard feeders, as well as nectar plants, play a crucial role in helping these birds survive migration as they provide a vital source of the food needed for fat stores.
Bidding Your Hummingbirds Farewell
It’s a bittersweet farewell for the backyard birdwatcher as their hummingbird feeders are no longer humming with activity. When the day comes that your feeder has emptied and the last of the hummingbirds have left, you might be thinking about removing the feeder. First, be sure that the hummingbirds have left for good. Likely, all the birds are indeed already migrating. But, if you remove your feeder before the last of the hummingbirds have migrated, they will find another feeder and may not return to yours next year.
Instead, consider maintaining your feeders until the first frost. When freezing becomes an issue, it’s a safe time to take down your hummingbird feeder. You should empty the nectar from your feeder, if any is left. Wash the feeder, dry thoroughly, and store it in a cool dry place.
Next spring you will be ready to greet these jewel-like visitors as they descend upon your yard once again, knowing what an amazing trip they have endured to get to you.