Post by Jen Berlinghof

For me, most days on the job consist of time in my “office” outdoors—a woodland, prairie or wetland in the Lake County Forest Preserves—with my “clients”—students, teachers, and families interested in learning more about local nature. On those rare days spent plunking away at a computer indoors, the photo above is my view. Recently, this view is bustling with activity, as hordes of ruby-throated hummingbirds buzz around the feeders, bulking up for a long flight south.

Mid-August through early September is peak migration for these charismatic and acrobatic birds—the only species of hummingbirds that nests in eastern North America. The number of hummingbirds headed south this time of year is often doubled from their northward spring migration, providing even more viewing opportunities in Lake County. Why are there so many more headed south in the fall? Because, this group of travelers includes the immature hummingbirds that hatched over the summer, as well as surviving adults.

What you may not see during fall migration is the shimmering, jewel-toned throat that is emblematic of adult male ruby-throated hummingbirds. Males only stay in the area for a few weeks, just long enough for courtship and mating. Then each male is off on its own, beginning migration earlier than females and young. Immature males look a lot like mom at this stage, although some are beginning to sport a tiny 5 o’clock shadow of darker throat feathers.

Scientists believe the urge to migrate for these birds is triggered by the shortening length of sunlight. When they sense the strong drive to migrate, they also get an urge to binge eat, needing almost doubled bodyweight to make it to their wintering grounds in Mexico and Panama. Some of the mighty even cross the entire Gulf of Mexico in a 500-mile non-stop flight, which is far for a bird that only weighs as much as a dime or two.

In preparation for this long flight, ruby-throated hummingbirds flit around to feast on tiny spiders, insects, and nectar. They primarily sip nectar from red and orange flowers, but certainly won’t turn their beaks up at feeders. Bird banding research shows that individual birds return to the spot where they hatched, even visiting the same feeders year after year. While it may seem that the hummingbirds are swarming your feeders in large groups, they actually lead solitary lives and do not migrate in flocks.

If you want to see these charming dynamos in action at the Lake County Forest Preserves, join us for a Walk on the Wildflower Side program where you may spy them visiting a flower, or visit the Ryerson Welcome Center and watch them at the feeders. You can help track hummingbird migration next spring by interacting with this migration map.

And, this? ⇩⇩⇩ Just for fun!