For the first time in nearly 40 years, 100 bald eagle chicks hatched and flew from their nests in New Hampshire this year.
The New Hampshire Audubon has been monitoring the state's bald eagle population since 1989, the year the first bald eagle chick fledged in the state after the insecticide DDT was banned. DDT was widely used throughout the 1960s and 1970s, before theU.S. Environmental Protection Agency banned the chemical in 1972 because of its environmental impacts, including driving bald eagles to the brink of extinction.
In the 1980s, New Hampshire had one successful breeding pair of bald eagles, according to data from NH Audubon. In 2026, 85 pairs of bald eagles incubated eggs around the state.
Mickayla Johnston, the New Hampshire Audubon's avian biologist, leads the bald eagle project. She spoke with NHPR's Morning Edition host Rick Ganley about the state's bald eagle success story and the 2026 breeding season.
Transcript
New Hampshire Audubon has been monitoring eagles around the state for nearly 40 years now. What is it that contributed to the decline of eagles in New Hampshire in the first place?
Yeah. So, like you just mentioned, DDT was the big threat facing eagles. And that was getting into the waterways, which was poisoning fish populations. So when they were ingesting the fish, DDT was sort of building up in their system. And essentially, what DDT does is make their eggshells too thin. And when they would go to incubate their eggs, they would inadvertently crush their own eggs.
Since starting the monitoring program, how does Audubon identify and track the birds every year?
Really, we rely largely on our volunteer monitors. So over the years, my predecessor Chris Martin has sort of amassed this great foundation of volunteer nest monitors for bald eagles. So we rely heavily on them. One thing that makes it sort of easier is the fact that, A, the bald eagle nests are pretty big and obvious in most cases. They'll also use the same nests year after year, and especially once a pair has been using a nest for a while the nests can get especially large.
The Audubon's kept up some very specific numbers on this population growth. I mean, how accurate is it? Are there likely some nests that we just don't know about?
I think, especially given how many volunteers we have now, our numbers are probably, you know, relatively accurate. But there are certainly nests that go each year undetected.
I mean, this is such good news. How have eagles become so successful in New Hampshire after being on the verge of extinction in the 1980s?
So [the] New Hampshire Fish and Game Nongame Program and New Hampshire Audubon have worked together for a long time on the bald eagle program. I think gathering a volunteer base from the start has made a really big difference. Really, the importance of tracking those nests is to make sure that there isn't human pressure from development and things like that that are bothering the birds during the breeding season. And if there are any issues that start to arise, New Hampshire Audubon and Fish and Game can sort of catch it early.
Are there still threats, though, that exist for the eagles?
Yeah, absolutely. So one of the big ones is rodenticides. We've seen a pretty big uptick in bald eagles, especially the chicks, having rodenticide poisoning.
I know as part of your summer field season, the Audubon and the Biodiversity Research Institute out of Portland, Maine, was actually able to place research bands on 20 bald eagle chicks around the state and collect some data from that. What's the process of placing a band on an eagle chick? I can't imagine that's the easiest thing to do.
Yeah. So, basically it starts with we have our partners, like you said, at BRI for short. A couple of the biologists are actually certified tree climbers. So what they do is they climb up the tree, carefully gather the chicks. They'll put them in sort of a soft container to slowly lower them down to us on the ground. So it'll be like myself and a few other biologists. And honestly, compared to other birds that I've banded — so like I've done songbird banding — the baby eagles are relatively easy to handle.
What about their parents, are their parents chill about it?
Surprisingly, yes. They will sort of just fly overhead circling the nest, especially when the climber is making his way up the tree and they'll just make their little chirp calls. And then when we're actually in the process of banding, they'll usually just perch somewhere close by. It's a pretty quick process. We'll put the bands on them, we take some morphological measurements and we collect samples for testing for Mercury, PFAS and lead, and then we'll put them back in the nest. And once everyone's gone from the area and it's been quiet for a few minutes, the adults will come back.
What do you do with that data that you've collected?
BRI in particular has banded hundreds of bald eagles. So, I mean, just New Hampshire's data on its own has given us tons of valuable information, particularly on like survival, their dispersal patterns. And that gives us lots of really valuable information on just bald eagle ecology in general and can also inform conservation and management practices in the future.
What does it tell us generally about the environment that these bald eagles are coming back?
If we can sort of band together behind the conservation of a particular species, we are absolutely able to have a successful conservation story.
