Inside the Amazing Cross-Continent Saga of the Steller’s Sea-Eagle


At 10 pounds and with a 7-foot wingspan, the Bald Eagle is one of the largest flying birds in the United States. Yet the two juvenile Bald Eagles I saw perched in a tree in Massachusetts on December 20, 2021 looked like pigeons compared to the other bird on the limb with them: a Steller’s Sea-Eagle.

Everything about seeing a Steller’s Sea-Eagle in New England is incredible. It’s an awe-inspiring bird—about a foot longer and taller than an adult Bald Eagle and as many as five pounds heavier, with a massive golden bill that looks like pirate treasure. It’s rare: There are only about 4,000 of this vulnerable species left in the wild, compared to hundreds of thousands of Bald Eagles. And of course, it’s not supposed to be here. Steller’s Sea-Eagles are native to far eastern Russia, the Korean peninsula, and northern Japan.

So how did this bird get to New England? It flew. The whole way. And it’s still flying now.

Vagrancy—the tendency for birds to show up far outside their normal range—is one of the most exciting aspects of birding. The Steller’s Sea-Eagle is the epitome of a vagrant bird, and the same individual has been tracked across North America since it was first spotted more than a year ago. The timeline and travels of this single bird, from Alaska to Texas to eastern Canada to New England, must be seen to be believed. Now the biggest question for birders is where this wandering giant will go next.

Graphic: Alex Tomlinson/Audubon

It’s hard to know exactly what condition the wandering Steller’s Sea-Eagle is in, but by all accounts it appears healthy. After all, it’s clearly strong enough to fly across an entire continent and take several hundred mile flights every couple of weeks. It has been observed feeding on fish at several locations and displays no sign of injury or illness.

Why the bird has strayed so far from its native range is anybody’s guess. Marshall Iliff, eBird project leader at the Cornell Lab of Ornithology and one of the first to spot the eagle in Massachusetts, says scientists are just beginning to understand the tendency of raptors to wander. “Raptors are more and more blowing our minds with their movements,” he says, “and with more observers, more cameras, and digital tools like eBird, we’re seeing that long-distance raptors dispersals are a rare but regular phenomenon.” Iliff says that many of these wandering raptors are juvenile birds dispersing to find new areas to live. There are other reasons birds show up far from their normal range, including habitat loss, weather events, and simply migrating in the wrong direction. (In its native range, the declining population is threatened by habitat loss, lead poisoning, climate change, and nestling predation by brown bears, according to International Union for Conservation of Nature.) 

Though it’s far from home and will likely never make it back, there’s a chance that this eagle could find a place it’d like to stay in North America. It’s not uncommon for individual vagrant birds to thrive in their new territory, such as the Red-billed Tropicbird that has returned to the Gulf of Maine for 16 years and counting. In fact, it’s possible that Steller’s Sea-Eagles could breed with local Bald Eagles, as evidenced by this supposed hybrid eagle seen in Juneau, Alaska, in 2004. 

When asked to guess the future of the Steller’s Sea-Eagle, Iliff said he could easily see it wandering North America for years to come. “I predict that we’re going to have a lot more fun with this bird,” he says. The only thing that’s certain with this bird is that, wherever it’s found, it’ll leave a group of stunned and elated birders in its wake.



Source link

Leave a Reply

Your email address will not be published. Required fields are marked *