Talk about an incredible journey.

A rufous hummingbird — a western bird that is not even supposed to be on the East Coast — has returned to Terri and Doug Elvey’s feeders in Quarryville for the second time in 10 months.

A birding expert estimates the 3-year-old female hummer, weighing little more than a penny, has flown 8,000 to 9,000 miles to breeding grounds in the Pacific Northwest and back since leaving the Elveys’ yard last Dec. 10. It had started dining there on Nov. 8 of last year.

Now, there it was again Oct. 8, feeding contentedly at a hummingbird feeder filled with nectar made from sugar and water.

“It just blows my mind,” Terri Elvey says.

How do we know all this about the dainty diner?

Scott Weidensaul, a well-known ornithologist and licensed bird bander from Schuylkill Haven, captured and banded the hummingbird at the Elveys’ home last November.

When the Elveys reported the bird had returned against all odds, Weidensaul again captured the hummer. Still on its right leg was the silver band with the identification numbers J51249.

The return of the hummer has not gone unnoticed in the birding world. As they did a year ago, birdwatchers are traveling to the Elveys’ house to see, photograph and videotape the unlikely guest.

The couple again are graciously allowing the public into their backyard to witness the amazing bird. They do ask that you contact them first to arrange a visit. Email them at telvey@comcast.net.

“It’s such an unusual thing. We want to share what we experienced,” Terri Elvey says. “This bird flew all this distance. It’s just exciting.”

Doug & Terri Elvey's Rufous Hummingbird from Andy McGann on Vimeo.

And the Elveys aren’t the only ones currently staring at a rufous. Another rufous was confirmed and banded just a few days ago at the home of Delmas and Ruth Witmer near Denver.

Birders are welcome, but not before 8 a.m. or after 6 p.m. Get permission and directions by emailing delmaswitmer@emypeople.net.

‘Vagrant’ birds

These hummingbirds are what is known in birding circles as “vagrants.” A vagrant is a bird that strays far beyond its expected breeding, wintering or migrating range.

According to Weidensaul, well more than 99 percent of rufous hummingbirds along the West Coast migrate south to winter in Mexico and breed in the Pacific Northwest, British Columbia and south-central Alaska.

They are hatched with this instinct that tells them when to migrate and in what direction.

Ornithologists believe that a small number of hummers have faulty “software” and strike off east instead of south for a winter range. In the past, this probably doomed them to death. But with climate change and warmer temperatures, these hummingbirds are surviving and spending winter in southeastern states. They pass on these genes to their progeny.

More and more rufous hummingbirds are showing up on the East Coast. In the winter of 2012-13, some 44 rufous hummingbirds were identified in Pennsylvania.

What is extremely rare, but not unprecedented, is the Elvey hummer — a banded bird returning to the same spot after a long migration across the continent.

This hummingbird, after it left the Elveys last December, likely headed south and wintered somewhere around Florida or Louisiana. Then it headed west and probably flew up the California coast to breeding grounds in the Pacific Northwest. Then, it struck out again for Quarryville.

How they navigate

What may be even more amazing than the fact that a bird returned to the same spot is how she did it. How does a slight bird navigate such an odyssey?

As Weidensaul quips, “We’re dealing with an animal with a brain the size of a Tic Tac. And for those of us who find it hard to find our car keys, it’s pretty humbling.”

For starters, hummingbirds have pretty good memories, Weidensaul notes. The Elvey hummer knows it had it pretty good in terms of plentiful food and security in the Quarryville yard last autumn.

And hummingbirds can remember routes, even very long ones, pretty well. The Elvey hummer has done the migration circuit a couple of times now. “She’s had her passport stamped a couple times,” Weidensaul says.

The hummer likely knows ridges and valley as geographic markers. But the real navigation skills revolve around cues from the earth, sun and stars — and quantum physics.

Birds pay attention to the rotation of the stars and parts of the sky that don’t rotate to gauge compass direction, Weidensaul says. Also, unlike humans, they can see the Earth’s magnetic field.

“They can see polarized light that moves across the sky in lockstep with with the sun during the day. They use the angle at which the bands of magnetism emanate from the earth. That angle varies with latitude.

“They are just more aware than we are,” he says

To help similar hummingbirds in unorthodox migrations, Weidensaul urges people who feed hummingbirds all summer to leave their feeders up until at least Thanksgiving.

Our native eastern hummingbirds — ruby-throated hummingbirds — should be about gone by this time of year. If you still have a hummingbird around after Oct. 15, Weidensaul wants to hear from you. It could be one of a handful of western hummingbirds. Contact him at scottweidensaul@verizon.net.