A bird born in Alaska this past summer recently flew to the other side of the planet, a distance of nearly 8,500 miles. It’s called a bar-tailed godwit, and the closest thing it has to a name is “B6.”
That’s what it says on a tag on its leg, anyway, and it’s the tag that allowed researchers to track the little shorebird’s 11-day flight from the Seward Peninsula in Alaska all the way to Tasmania, the island state of Australia.
The epic journey also captured the attention of both casual and hardcore bird enthusiasts around the world.
But before it was internationally famous, B6 was just another godwit chick in Alaska, where wildlife biologist Dan Ruthrauff with the U.S. Geological Survey found it.
Ruthrauff says, for the humans, finding it to put a tag on it was the hardest part.
The following transcript has been lightly edited for clarity.
Dan Ruthrauff: The idea was that we’d follow these chicks until they were big enough to put a big fancy transmitter on them. And then we wave goodbye to them and, you know, watch all these chicks fly to New Zealand. And in practice, they just walked a lot further than we could and we could not keep up with them. And so we were super lucky, we did deploy these fancy tags on B6 and two brood mates, two siblings. The problem was those birds dropped their radios, because we put these tags on very loosely, because the chicks were still growing.
Casey Grove: Yeah, I mean, I wasn’t sure if, like, when the migration starts, if you’re tracking multiple birds, and B6 just happened to be the one that made it that far, but it sounds like that was the one to track, right?
DR: It was the only one. And we were very thankful that we even had one, you know, after we retreated from Nome, like, “Well, that didn’t work so well.” We were happy to have this one bird. We thought, “This will be great. We’ll track it to New Zealand.” But it really surprised us and went much, much further than New Zealand. So sometimes, you know, a sample size of one can provide some of the most amazing insights. So this was definitely not something we expected, a bird going that far.
CG: Yeah, I mean, maybe that even indicates that it’s not that uncommon, right, for them to fly that far?
DR: Yeah, I think that’s a funny human perception we have, that, “Why would these birds fly nonstop over the Pacific Ocean? That seems very dangerous.” And it would be crazy for you or I to try this, right? And so we can’t even conceive of what an overwater, nonstop flight is like. To humans, that seems very dangerous. But to these birds, I think it’s reliable, that, you know, the Aleutian low sets up every fall, they take off on a big low-pressure system, they get a huge tailwind. I mean, it’s a long flight. And they’re, you know, some of the only animals that do this. It’s the longest nonstop bird migration in the world. But the population’s stable, they’re doing well, they seem to be able to support this and so that this bird went to Tasmania speaks volumes about their capacity. I’m sure this bird may look for a shorter stop the next time it does this migration. You know, ideally, you want to expend as little energy as possible, and this bird went as pretty much as far as you can possibly go.
CG: I mean, I just had to laugh when you said that, because it’s like, if the headline is, “An Alaska bird flew to Tasmania,” that seems ridiculous, right?
DR: It’s totally ridiculous, yeah. And, you know, my predecessors at the U.S. Geological Survey, they documented this migration back in 2005. They tracked a bird that did this, and it never fails to amaze people, because it just seems so improbable. And, especially, you can sort of anticipate the wonder of a juvenile bird. So this bird was like four months old. It’s crazy. It had hatched on the Seward Peninsula in early July, and it had to grow into an adult size and put on, you know, 50% fat so it could fuel this migration. So it’s doing just amazing, incomprehensible things in its first four months of life, and tops it off by flying to Tasmania.
CG: Yeah, and you can’t really overstate that either, right? Because, I mean, we’ve heard about godwits before, I have, and flying this amazing distance from, you know, Alaska to the southern hemisphere. But they’re adults. Like, presumably they’ve done it at least once, right?
CG: But this bird was just born last season, then migration season came. My understanding is the adults take off earlier, right? To give the chicks more time? So they’re it’s not like they’re flying with them, showing them the way.
DR: That’s correct.
CG: How in the world does that work? How do they do that?
DR: Honestly, we have no idea. I wish I could give you a better answer. But you’re exactly right, that the adults tend to precede the juveniles, that, just based on observations from New Zealand and eastern Australia, the adults start to — and you know, I’ve spent plenty of time on the Kuskokwim Delta in the fall — the birds start to leave in late August. Those are the adults. Pretty soon, it’s only juveniles that remain in Alaska. And soon they disappear as well. And this bird left quite a bit later than we thought. It departed the Yukon Delta on October 13, and we were starting to get worried, we thought, “This bird’s not going to fly.” And that just shows you how little we know. But yeah, we learned a lot from this one bird.
CG: And I guess part of this, too, is that as far as we know, the bar-tailed godwits that breed in Alaska are doing pretty well, right? But godwits in other places are not, and I understand that’s part of why you’re you’re looking at them.
DR: Yeah, that’s the ultimate motivation for this, is that shorebirds in North America, there’s been really steep, documented declines over the last 50 years. And 50 years is a long time. It’s long enough that humans might not even perceive it, unless they had somebody collecting data in the 1970s, 1980s, 1990s, looking at these stopover sites and how many birds are coming through. So there’s really solid information that these populations have declined. And yet it’s hard for us to perceive that, but our colleagues in Australia (and) New Zealand, have done really good monitoring of the bar-tailed godwits during our winter, which is the summer in New Zealand. And the population counts tend to fluctuate. And they were maybe higher 25 years ago by 20,000 birds or so. But they’ve been pretty stable at about 125,000 bar-tailed godwits for the last, oh, say five to seven years. That’s great. Some of the other subspecies of bar-tailed godwits are declining precipitously. They are bar-tailed godwits that live in Western Australia that breed in Siberia. Their populations are declining very rapidly. So exactly what you said, we’re trying to better understand why one godwit population is stable while others are declining.