– As he scanned the sky from his overlook on Thompson Hill, John Richardson remembered a time when bald eagle sightings were rare.

This spring, the counter for Hawk Ridge Bird Observatory will see dozens — even hundreds — of the raptors in a single day.

Over the past few decades, Duluth has become a traffic hub for birds migrating in March, April and May. With its rivers, creeks and the shoreline of Lake Superior as guiding maps from above, the city is at times the best place in the country to spot a bald eagle.

“We keep seeing more and more each year,” Richardson said.

On a late March day in 2019, Hawk Ridge counters tallied 1,076 bald eagles — a single-day record for any site in North America. Staff from the nonprofit observatory counted 7,727 bald eagles during the 2019 spring migration, the most recorded during the March through May season in Hawk Ridge’s history.

“Of course you can see them elsewhere in Minnesota,” Richardson said. “But you won’t see them in such concentrations as you do in Duluth.”

He credits federal legislation protecting migratory birds and the banning of DDT, an insecticide that poisoned eagles, with saving the species that was once in danger of extinction. The bald eagle was removed from the Federal List of Endangered and Threatened Wildlife in 2007.

As of Monday morning, Hawk Ridge counters have seen more than 2,800 bald eagles pass through Duluth this spring, and a second wave of migrators usually starts in late April. Not all bald eagles migrate.

Some of the birds will come from as far south as Florida, while others that wintered in southern Minnesota could be passing through on their way to summer nests in the most northerly forests of Canada.

“These birds could even be heading all the way to Alaska,” Richardson said as he watched an eagle catch lift on a stream of warm air.

Richardson and Frank Nicoletti, who runs Hawk Ridge’s spring count, are out with a rotating handful of volunteers every day in the spring monitoring migrations.

Armed with binoculars and spotting scopes, they are able to identify a bird’s species (and, sometimes, gender and age) when they’re just tiny specks in the sky by looking at the shapes of tails and the way the animals fly.

Hawk Ridge’s spring count is smaller than its fall season, which ends in November. Still, as the weather warms — sunny days with some southerly wind are the best — many birds are on the move.

The Hawk Ridge group had its best day of the season Sunday in terms of total raptors — 1,114, including a whopping 785 red-tailed hawks, the first common loon of the year and 91 bald eagles.

Though this year’s bald eagle numbers are currently behind last year’s, Richardson said, the counters could still see jumps this spring. It’s all dependent on the weather — northeast winds in March may have altered the paths of the birds so that many made the journey North without passing through Duluth.

“It doesn’t mean that the population is down,” he said. “It just means that they’re not flying right over our heads.”