A bald eagle takes flight from a tree in the Scarborough Marsh in January. People also refer to bald eagles colloquially as sea eagles, and in fact, that is actually what their scientific name, Haliaeetus leucocephalus, means. Shawn Patrick Ouellette/Staff Photographer

One helpful thing when communicating about birds is that we generally have an agreed-upon set of names for each species, set by the American Ornithological Society’s Classification and Nomenclature committee. It’s pretty straightforward, at least compared to plants, which can have many different common names, often causing confusion and having experts resort to using Latin binomial names (which can be still more confusing to novices).

Bird names can also lead to befuddlement, though, and it’s usually because of the colloquial names we use. I wanted to dive into this lexical analysis of the term “sea eagle” thanks to a question that came in from Dan Colacino of Delmar, New York. Dan was recently at Perkins Cove in Ogunquit and overheard a conversation (or argument) about an eagle perched on a rock in Oarweed Cove. One party called it a bald eagle, and the other said it was a sea eagle. Who was right?

The easy answer is that they are both (mostly) correct! The exact species, and name you’ll find in any (English) field guide, is “bald eagle.” This is our national symbol, and 99.99% of the eagles that we see in Maine are bald eagles. But people also refer to bald eagles colloquially as sea eagles, and in fact, that is actually what their scientific name, Haliaeetus leucocephalus, means.

Haliaeetus is the genus that includes bald eagles, which translates to sea eagle, from the Greek hali- (or halo), meaning sea, and aetos, meaning eagle. While we’re at it, leucocephalus breaks down to leukos, meaning white, and kephalos, meaning headed, so bald eagles would be better named “white-headed sea eagles.”

So we’re all happy to call bald eagles sea eagles, but the real confusion arises when we talk about osprey. These large piscivorous (fish-eating) birds of prey are just a bit smaller than a bald eagle and are often encountered in the same areas since both species love dining on fish. A commonly-used colloquial name for the osprey is, of course, sea eagle, or sea hawk. And that isn’t wrong either! The scientific name of osprey is Pandion haliaetus, which should sound familiar. Pandion apparently comes from a king of Athens in Greek mythology, but haliaetus is the same word we saw as the genus including our bald eagle. They’re all sea eagles!

I’ll try to stop myself before going too deep down the Seattle Seahawks rabbit hole. Their mascot, Blitz, vaguely resembles an osprey that flew through some sort of radioactive material. And the live hawk that they bring out onto the field is actually an augur buzzard, native to east Africa.

There is, of course, one other sea eagle we need to discuss: the Steller’s Sea-Eagle. This enormous eagle from eastern Siberia made headlines the last two winters. This lone individual strayed all the way to Maine, spending subsequent seasons around Georgetown. This species is actually in the same genus as bald eagle, though its name, Haliaeetus pelagicus, means it is the “sea-eagle of the sea.” For those wondering, “our” Steller’s Sea-Eagle (which many people affectionately call “Stella,” but that would take a whole separate article to unpack), has been seen in Newfoundland as recently as June 19 in Trinity.

The last thing you should know about sea eagles, especially if you find yourself in the puzzles section, is that sea eagle can also be called “ern.” Or if you need four letters, try “erne.” I don’t know why, but remembering this will definitely help in many crossword puzzles.

NESTING SEASON FOR HUMMINGBIRDS

A perennial question we receive each summer, which I love discussing, is regarding the apparent disappearance of some birds in the summer. Each spring, millions of birds return to Maine to breed, many of them singing each morning as they find a mate and defend their territories. But now, in late June, they seem to have disappeared. Jay Burnett of Camden noticed this “absence” of backyard ruby-throated hummingbirds, a species that is usually easy to detect thanks to feeders or plants in the yard. So where have all these birds gone?

The answer lies in their nesting behaviors: They were easy to detect through the spring when they were singing and looking for food, but now they are in the peak of their nesting season, so their detectability drops significantly. That’s because they really don’t want to be found while they are nesting, so singing decreases and conspicuous breeding displays don’t need to be performed anymore.

We can actually measure this decreased detectability using citizen science projects like Cornell’s eBird, which asks observers to submit checklists of what birds they see, when and where, and with how much effort. That effort component is important because we can then measure things like frequency. By frequency, we mean what percentage of all checklists report a particular species. For example, the frequency of checklists that report observing ruby-throated hummingbirds in Maine jumps from zero to just over 20% by the second week of May.

You’d think that would remain high, since the hummers stick around and breed all summer, but the amount of checklists they’re reported on drops to its lowest point in late June, around 9%, because they are focused on nesting (so not observed as often). Throughout July and August, that frequency slowly climbs as young birds fledge and they will become more common at bird feeders again, with a second peak in late August, before virtually all of them leave by early October.

The important thing to remember during this drop in sightings is that those hummingbirds are spending more time collecting insects to feed both themselves and their young. Providing a hummingbird feeder is great (keep it clean!), but the best things you can do to help hummingbirds in the summer are to make sure you’ve got plenty of native plants, and avoid using pesticides in your yards. This will keep the insect population healthy, which is critical to the next generation of birds that are slowly developing in our backyards.

Do you have a nature question for Doug? Email questions to ask@maineaudubon.org and visit maineaudubon.org to learn more about birding, native plants, and programs and events focusing on Maine wildlife and habitat. Doug and other naturalists lead free bird walks on Thursday mornings, 7 to 9 a.m., at the Gilsland Farm Audubon Sanctuary in Falmouth.