An Exciting First Season of Morning Flight Counting at Eagle Harbor

This spring marked the first season of morning flight counting at Eagle Harbor,

a new migration monitoring effort of the Copper Country Bird Club called the

Keweenaw Bird Observatory. From April 17 through June 4, we counted on

most mornings, documenting the procession of spring migration along the

south shore of Lake Superior.

Blackburnian Warbler [Setophaga fusca] (photo by Skye Haas).

Over the season, we conducted 91 hours and 45 minutes of observation and

we recorded 38,921 individual birds representing 157 species. As expected,

the bulk of the migration passed through in May, when we recorded 28,342

birds, compared with 9,651 birds in April and 928 birds in June. Of the full-

season total, 36,471 birds were moving west along the shoreline, while

2,450 were moving east toward the tip of the Keweenaw Peninsula. These

results strongly suggest that many migrants moving west along the coastline

near Eagle Harbor are reorienting, likely after encountering strong westerly

winds while attempting to cross the open waters of Lake Superior the previous

night.

For a first season, the results are beyond what we expected to find. We

recorded multiple days with more than 1,000 birds in active morning flight,

including several major movements that highlighted just how important Eagle

Harbor may be as a migration site in the Upper Great Lakes.

The season started dramatically on April 17, when strong southeast winds

brought a major early-season movement. In just three hours, we tallied 2,731

actively migrating birds of 49 species, including 1,475 Dark-eyed Juncos,

159 Northern Flickers, 173 Common Redpolls, and 86 Yellow-rumped

Warblers. Many other small songbirds, including kinglets and sparrows, were

seen launching directly across the harbor, buffeted by strong winds as they moved north.

Northern Flicker [Colaptes auratus] (photo by Skye Haas)

Just a few days later, on April 23, the skies were filled with blackbirds. The

highlight was a spectacular movement of 2,461 Rusty Blackbirds, with flocks

at times stretching across the sky as they streamed through the Keweenaw.

Also abundant that day were 1,071 American Robins, 155 Purple Finches,

142 American Tree Sparrows, and 180 Dark-eyed Juncos.

Rusty Blackbirds [Euphagus carolinus] (photo by Rowan Gibson)

By May, warbler migration had begun to build. On May 9, south winds

overnight followed by strong westerly gusts over Lake Superior produced an

impressive morning flight of birds working to avoid being blown out over the

open lake. In four hours, we counted 6,593 birds of 54 migrating species,

including 4,242 Yellow-rumped Warblers, 432 Palm Warblers, 49 Cape

May Warblers. In total, 12 warbler species were recorded that morning, with

this day representing the peak of Yellow-rumped Warbler migration.

Yellow-rumped Warbler [Setophaga coronata] (photo by Skye Haas)

On May 15, following heavy morning rain and increasing westerly wind, we

counted 5,045 birds of 54 migrating species, including 1,100 Yellow-

rumped Warblers, 446 Nashville Warblers, 372 Palm Warblers, 82 Cape

May Warblers, 34 Black-and-white Warblers, and 29 Magnolia Warblers.

In total, 19 warbler species were recorded that morning. We also observed 155

American Pipits, 121 Pine Siskins, and single American Golden-Plover,

Scarlet Tanager, and Dickcissel, a rare species in our area.

As the westerly winds strengthened that morning, many birds flew incredibly

low, skimming the tops of bushes and grass. Others attempting to cross the

harbor appeared almost suspended in place over the water as they fought

against powerful gusts.

The largest flight of the season came on May 16, when 7,848 migrants passed

overhead in a little over three hours after making landfall off Lake Superior.

This included 1,614 Yellow-rumped Warblers, 655 Palm Warblers, 465

Nashville Warblers, 198 Cape May Warblers, 133 Magnolia Warblers, and

18 total warbler species. We also observed a Red-headed Woodpecker

traveling with 1,557 Blue Jays, as well as a Brewer’s Blackbird, both

uncommon birds in the Keweenaw.

Migration continued to provide surprises through late May. On May 26,

although radar suggested the possibility of a massive morning flight, overnight

rain likely reduced the movement. Even so, the morning produced an

impressive 1,824 individuals representing 61 migrant species. Early in the

morning, there was an intense but short-lived pulse of 556 Cedar Waxwings,

while 612 Blue Jays moved throughout the day. Warbler diversity was

especially strong, with 21 warbler species recorded, including 76 Cape May

Warblers, 45 American Redstarts, and 37 Palm Warblers.

Later that morning, a flock of seven Eurasian Tree Sparrows flew by and

briefly landed in shrubs near the weather station before continuing west -- one of several notable rarities recorded during the season.

A flock, rare to the Keweenaw -- Eurasian Tree Sparrows [Passer montanus] (photo by Skye Haas)

Taken together, these first-season results support the idea that Eagle Harbor is

an important site for documenting spring bird migration in the Upper Great

Lakes. The count captured not only large numbers of migrants, but also the

dramatic ways birds respond to wind, weather, and the open-water barrier of

Lake Superior. Other rare species recorded on the count included two

Harlequin Ducks, and a flyover Chestnut-collared Longspur.

We believe this first season was a major success and an important step toward

establishing Eagle Harbor as a long-term population monitoring and migration

research site. Our goal for spring 2027 is to hire a dedicated expert morning

flight counter so the count can be conducted in an even more standardized

way, while allowing our director, Zach Gayk, to focus more fully on analyzing

results, coordinating research, and expanding community outreach.

This project would not have been possible without support from the Upper

Peninsula Environmental Coalition, the Keweenaw Community

Foundation, the Keweenaw Community Forest Company, and the Steven

C. Leuthold Family Foundation. We are deeply grateful for their support of

this new effort to better understand and protect bird migration in the

Keweenaw.

If you would like to support the Keweenaw Bird Observatory and help us

monitor population trends of migratory birds, as well conduct research on how multiple songbirds migrate together as part of a community of species, please

consider making a tax-deductible donation to the Copper Country Bird Club,

earmarked for the Keweenaw Bird Observatory. Please stay tuned for fall when

we will deploy new technology for monitoring the calls of migratory birds in

real time.

Donate or join: www.coppercountrybirds.org/join