The Hawai'i Voices of Science episodes tell natural resource stories on Hawai'i Island.
The Hawaiian Goose, or nēnē, is the rarest goose in the world. It’s found only in the state of Hawaii. In the 1950’s, the species was on the brink of extinction. With the help of biologists like Kathleen Misajon in Hawaii Volcanoes National Park, the nēnē population is rebounding.
Voices of Science: The Rarest Goose in the World
The Hawaiian Goose, or nēnē, is the rarest goose in the world.
Narrator: For the National Park Service, I’m Brittni Connell, and you’re listening to Voices of Science.
Kathleen Misajon crouches in the dry grass eagerly watching a pair of geese. She lowers her binoculars and leans in.
Kathleen: So people always ask me how you tell the difference between male and female because they have the exact same plumage. But, this is the best time of year to tell them apart.
You can see this pair in front of us. She's just focused on eating as they're getting ready to nest. She's only focused on eating, and he's just alert the whole time. So, he's kind of guarding her while she just cruises along and eats. And you can even see she's starting to get a little bit rounder in the back. She's fattening up just the slightest bit, getting ready for nesting.
Narrator: Kathleen is a biologist at Hawaii Volcanoes National Park. Her main study subject is the nēnē, or Hawaiian goose. Kathleen has been working with the birds for nearly 20 years.
Kathleen: They're behavior is so interesting and they’re highly social and so what's been really fun for me working here all these years is that most of them are banded and I know them individually — who they are. And so you can really start to see who's who and start to see the relationships between them.
Narrator: The pair we’re watching are building a relationship of their own.
Kathleen: See how you can hear the male giving that kind of trumpeting, and that quieter, quicker sound in the background is the female, as she's sort of answering along as they parade through the area.
What's so interesting with these pairs is they mate for life, and they just develop these little calls and communications. It's like they're constantly communicating back and forth to where the other one is and what the other one's doing.
Narrator: These birds are unique to Hawaii. For millennia, the nēnē thrived on the islands. Before western contact, the nēnē population was estimated to be close to 25,000 birds.
Kathleen: All of these species evolved without human impact, and without mammals basically. And so when people started coming and bringing different animals and insects and diseases – and all of these things were introduced to the islands – the species here were not adapted to those things. And so they easily fell prey.
Narrator: By the early 1900s, the nēnē population plummeted.
Kathleen: Nēnē by 1900 they were extinct from all the other main Hawaiian Islands. And they were only found on this island. And by 1950 or so, there were an estimated 30 birds left in the wild. So it is a species that really was on the brink of extinction.
Narrator: The nēnē were protected under the Endangered Species Act in 1967. Shortly thereafter, Hawaii Volcanoes National Park established a captive breeding program to try to recover the species. The birds were bred and raised in captivity, and the young fledglings were released into the wild.
Kathleen: So this is one of the areas where the park first started introducing nēnē back into the wild. And these over here are actually in the same site as the original pens that were built in the early 1980s…
Narrator: Kathleen shows us the original reintroduction area. It’s an old pasture surrounded by native shrubland. It’s wide and open. Covered with late-summer grass. The nene still use it today. It’s great natural habitat for the birds to boost their body condition as they get ready to nest, so it’s a popular — and critical — foraging spot for them.
It’s also within striking distance of nēnē nesting sites — which are these crazy-rugged areas out on the lava flows.
Kathleen: You know sparsely vegetated lava flows, shrubby, scrubby kind of areas, so they nest out in those areas, it’s more open and more remote. And then once they hatch, the very next day they start marching out to what we would call the brooding area.
Narrator: These are tough birds. And they’re incredibly long-lived. Nēnē can live for as long as 30 years. In fact, some of the original breeding pairs from the early recovery efforts were still alive when Kathleen began working with the birds .
Kathleen: Well, I think I was kind of amazed when I first got here, knowing the history of the program. But, to actually then see some of those very first pairs that were still here. And suddenly it was my job to look after those birds. It was kind of an honor really.
Narrator: Over the years, the Hawaii Volcanoes nene program evolved and Kathleen’s role along with it. The captive breeding project was just the beginning of a more comprehensive recovery effort.
Kathleen: You know we really needed the captive breeding early on to get the numbers going and get the birds back on the landscape, but as time went on you know it was really important to shift over to improve the landscape to give them the best shot that's out there.
And so the park shifted in the 1980s from focusing on breeding birds in pens and releasing them into the wild and put more of an emphasis on actually improving their odds in the wild, improving the habitat and reducing the predator numbers and trying to support the wild breeding rather than just focusing on the captive breeding. And so I think really the combination of those two were key.
Narrator: Today, the nēnē population is rebounding. And in March of 2018, the US Fish and Wildlife Service proposed a change in the nēnē’s status. From endangered to threatened.
Kathleen: So within the park we're right around 250 birds, but statewide, the population's right about 3000. Which is a pretty impressive, from 30 in the 1950s.
Narrator: It’s a testament to both the success of the recovery efforts and why the Endangered Species Act really works.
Kathleen: It is, but I think what's always important to remember with this species and with most of our endangered species here is that...it's not over…while we can get the numbers back up and improve the situation, they're always going to be reliant on some level of assistance from humans, whether it's improving habitat or removing more predators or you know creating new habitat as the numbers grow.
So I think nēnē really are a great success story, but the story doesn't end. It's gonna be, you know it's work in perpetuity, in order to keep the species alive.
Narrator: While we’re talking, the nēnē pair, seem less concerned with our presence, but they lock on to something overhead.
Kathleen: They evolved with only avian predators, so they're really keyed into concerns in the sky. They're really keyed into what's flying over. ‘Cause, they evolved with hawks, right? So anything that's flying over they're watching, they're looking. They're alerted.
Speaker 1: But on the ground?
Kathleen: On the ground they have to learn it. It's not, you know wired.
Narrator: That moment of watching the nene — so alert to threats overhead, but somewhat indifferent to us on the ground — really underscored for me the need to remain vigilant in protecting the nēnē.
Kathleen: We remind everyone driving in the park to be cautious and to keep an eye out for nēnē. And the other real key thing is to make sure people don't feed them. Nēnē are very adaptable and they quickly learn about handouts, and unfortunately the birds that are fed do start to gravitate towards people, and towards parking areas where they think they can get a handout, and those birds do usually end up eventually being killed by cars.
Narrator: It’s small steps like these that go a long way toward helping the rarest goose in the world stay on the path to recovery. Kathleen says the nēnē are an integral part of this ecosystem. And they’re part of what makes this place so special.
Kathleen: It’s just so interesting to watch these birds year after year and generation after generation. See how they return to their same spots. See how they use the landscape, and use the natural habitat, these barren lava flows that you would think, you know, why would they be out there? But, it works for them. It's just ... They clearly belong there. And it's nice to be a part of helping ensure that they stay there.
Narrator: Voices of Science was produced by the National Park Service in collaboration with the Acoustic Atlas at Montana State University.
Our staff includes Jennifer Jerret, David Restivo, Sara Melena, and me, Brittni Connell.
Special thanks to Jessica Faracane and Kathleen Misajon at Hawaii Volcanoes National Park. You can learn more about the park at nps.gov/havo. Learn more about Voices of Science and find more episodes at go.nps.gov/vos. Thanks for listening.