The Yukon Delta National Wildlife Refuge is an important staging and breeding ground for all sorts of birds. During the spring and summer, biologists spend weeks out on the tundra collecting population information and banding birds to help guide management of the bird populations that rely on the region.
Waterfowl biologists Bryan Daniels and Randall Friendly stopped by KYUK to give an update on field research and avian influenza on the Yukon-Kuskokwim (Y-K) Delta.
Read a transcript of the conversation below (lightly edited for clarity and flow, but may contain transcription errors):
Mathew Hunter: Joining us for "Coffee [at KYUK]" this morning are two biologists with the Yukon Delta National Wildlife Refuge. Bryan Daniels and Randall Friendly have just returned from counting and studying waterfowl out on the coast. Here to speak with them about the importance of these birds and some of the challenges they face is KYUK’s Sage Smiley.
KYUK (Sage Smiley): Good morning. Thanks for being here today.
Bryan Daniels: Good morning.
Randall Friendly: Good morning.
KYUK: To start out, can we maybe first just hear who you are and what you do at the Yukon Delta National Wildlife Refuge?
Daniels: Yeah, my name is Bryan Daniels and I am the lead waterfowl biologist here at Yukon Delta. So my, I guess, job description is to study and research waterfowl nests, ecology, populations, and harvest management of the waterfowl, which is primarily ducks and geese, but that does also encompass swans. And also now, as lead waterfowl biologist, is also to guide Randall and assist with projects, and acquire funding and acquire new projects that need to be done. Talking to the management and Pacific Flyway Council and Alaska Migratory Bird Co-Management Council and just find out what information is needed and then plan those projects.
Friendly: And my name is Randall Friendly. And as Bryan said, I'm the second waterfowl biologist. My job description is pretty similar to what Bryan does. Over the course of the summer we’ll share projects, you know, help each other out. And what I'm most interested in is working with ducks and geese in general, and also learning about their population ecology.
KYUK: So you're in between field work right now. What are you coming back from? What have you been working on this summer?
Daniels: So our first major project is from the middle of May through the end of June. And we have a field camp out on Kigigak Island, which is just west of Newtok here on the Yukon Delta. And that project is primarily looking at nest success and nest ecology of emperor geese. But we also partner with another program, Ecological Services with [the United States] Fish and Wildlife [Service], who study spectacled eider, threatened spectacled eider nest ecology and survival. And we're also looking at adult female survival, because their populations are driven by adult female survival. They’re long-lived; they have small clutch sizes. And so females surviving year to year is what drives population growth. And so we're studying that out on the island.
Friendly: And then the next coming field projects, which are my projects, are going to be the cackler banding, and then the preseason duck banding at Kgun Lake. So first field work for cackler banding is we'll go to Chevak and then boat down to Tutakoke River camp where we’ll meet up with the Colorado State University crew. And that's basically when you know [the U.S.] Fish and Wildlife [Service] and the university will come together and help together band and capture black brant and cacklers by ground-based drives. And this year I think we'll use a helicopter concurrently during that time. But after that season is over, we'll head to another field camp, and that’s where we will be banding ducks and geese, primarily pintails, mallards, and some teal. And the main purpose of that is for harvest management that is used on the Pacific Flyway. And that's pretty much it.
KYUK: Cool. So I do want to return to that banding idea and kind of what that helps with, but first in looking at the projects that you've been doing, how are these populations doing? And how does that compare to what you've seen in previous years?
Daniels: So the population of emperor geese, I haven't gotten the metrics for what the estimate is for this year, because that's actually flown – the population itself is counted by aerial surveys. And we haven't gotten those metrics yet; should be in the next month or so. But in terms of nest success and annual survival from last year to this year, annual survival was high of emperor geese. I think I calculated around 83% for this last year, which is what you're wanting to see. And then nest success was high, it was in the high 80%. And so that means that, you know, foxes and gulls didn’t depredate as many nests and that was good.
KYUK: So what does that mean for management strategy then?
Daniels: So management strategy is, we obviously want the population to either stay stable or grow because right now it is just above the population threshold for closure for harvest. And so this is only one really small study site on the entire Yukon Delta, right? So it's hard to make sure that it is going to be the same across the Yukon Delta, right? But at least at our study site, it shows that the population should be stable or growing at a study site based on the survival of the adult geese, as well as producing enough goslings to hopefully replace themselves in the future.
KYUK: So then, with banding projects and those sorts of things, how does that either inform research or management of these populations?
Friendly: So every year, we band a different number of ducks and geese each year. Some years it's low, some years it's high. And you know, on the low years, you can get sometimes, you know what it may be. Just recently, within two years ago, when avian influenza hit hard on the Yukon Delta, there was a lot of ducks and geese that forego nesting, and there wasn't a lot of birds around that time. So that was one of the low years. But with the following years after that, the geese in particular have been, I'd say, doing alright since, you know, the number of birds we've banded over two years since avian influenza happened has been increasing. And last year was actually the most cacklers we’ve banded since 2016. And as for the ducks, I feel like the best way to compare over the years, I think, across eight years, the first four years, I feel like they were more productive. There were more birds around or staging in the areas they normally staged, but the last four years has kind of been, like, pretty variable if we look at a high number of species and a low number of the species.
KYUK: Can you identify what is causing that variability, or is that still something that y'all are studying?
Friendly: It's something that, you know, can be looked at; we're not currently exactly studying that. But, you know, there are some ideas, some of these staging areas or where ducks may decide to forage on under migrating is when we're, when we're actually trying to trap them. The conditions during these areas kind of depend on it. So like if there's high waters in these ponds, or lakes, or low levels, if the water levels are pretty high the teals that are shorter are not going to be able to forage around those areas or dabble. So won't be seeing a lot of those for the water levels that are high. If they're low, you know, you might see a lot of that, and maybe not a lot of this species, but it varies. I feel like they're more like factors that can be speculated into. Can't give the best answer to that.
Daniels: And back to the banding data and what it tells us so cackling geese in particular are highly susceptible to over-harvest. And so their population fluctuates based on harvest rates. And so we band the cackling geese here. And most harvest of cackling geese occurs in Oregon and Washington. And so when they have higher daily bag limits, we see the population decline. And when they have lower bag limits, the population increases. And so we can manage the population based on harvest down in Oregon and Washington and that's what a lot of this banding data is used for. And currently, Oregon, Washington are decreasing their bag limits so the population will come back up. And then for ducks, we use the same thing. It's primarily mallards are our target species. And it goes into a nationwide adaptive harvest management for setting regulations in the lower 48 and Alaska for all species, it's what it's used for.
KYUK: That sounds like a pretty complicated system for communicating between all these different agencies and across state lines and everything. I know that that's difficult with fisheries and I imagine it also is with bird populations?
Daniels: I would say it is easier with bird populations because the populations are greater. And we have actual management plans in place, whereas a lot of fisheries don't have active management plans that are being followed. Whereas waterfowl, we have the Migratory Bird Treaty Act, you know, between Japan and Mexico, Canada, United States. And so in the past, you know, all the countries come together and discuss what we want to see and what management can look like. And so we follow those pretty strictly to ensure harvest and availability to all users.
Friendly: Yeah, and I'd say just to piggyback on Bryan: birds or ducks and geese in general are a lot easier to study than fish. You know, we can do monitoring in all seasons.
KYUK: Yeah, totally. So Randall, you mentioned avian flu, and I know that that is something that people are concerned about. Waterfowl are very important to the region for a number of reasons. So how are avian flu rates looking in the region?
Friendly: I think Bryan can better answer that question, since he's working with people that are looking into that.
KYUK: All right, Bryan?
Daniels: So in 2022, there was a large outbreak in Alaska of avian influenza. And we found that a lot of species are still finding that a lot of species are being detected with avian influenza, and it's gone across multiple taxons, right? So it's being found in cats, being found in seals, being found in whales, being found in foxes, bears, and then multiple species of birds. Prior to this strain, it was only found in ducks and geese. And so we're seeing that it's having a farther-ranging effect than ever before. But it is not affecting most populations at a population level, it's at a more individual level. Populations of birds themselves are doing just fine.
KYUK: Okay, so that's positive then? Trending in the right direction?
Daniels: I wouldn't say it's positive, but it is positive to know that birds are able to withstand a large outbreak like this, and populations themselves are not going to decrease. And the species, at least the species that they're being detected in right now, are not in peril. And they're able to fight it off so that their populations are still able to survive and continue on. So it's not wiping out entire populations.
KYUK: In your experience studying birds, shorebirds, waterfowl on the Y-K Delta, what is the significance of the delta to these populations?
Daniels: So it all depends on the species, right? So the Yukon Delta is an extremely important location. We have one of the most dense nesting areas of anywhere in the world for waterfowl and shorebirds. The cackling goose population, the minima subspecies, specifically, 100% of their population nests on the Yukon Delta. Ninety percent of emperor geese population nests on the Yukon Delta. Sixty percent of threatened spectacled eiders nest on the Yukon Delta. And so it's very important. And then we have greater than 30% of world populations of a lot of shorebirds, so like bristle-thighed curlews, dunlin. And there's some other species that I can't remember off top my head, but we're very important for their nesting. But not only nesting, but also migratory routes. And so the Yukon Delta is part of a couple networks. We're designated in the East Asian Australian flyway network as an important location for birds that fly over to Asia. We’re part of the Western Hemisphere Shorebird Reserve Network, which is an important stopover location for the western hemisphere. And then we're also really important for the Pacific Flyway here in North America.
KYUK: Anything you'd want to add Randall?
Friendly: Yeah, I'd say the importance of the Y-K Delta is, as Bryan said, it hosts, say, millions of millions of bird species across or across all species. And a lot of or, I think, all of the birds in different flyways, you know, all come to the Yukon Delta to either nest or, you know, use it as a staging location. Like the bar-tailed godwit, most of most of the world population nest here in the Yukon Delta and, you know, they have the longest flight migration route or the longest flight time, you know? What some like the Arctic tern like winter all the way into east coast, they come up here, you know, having the longest distance of migration. So a lot of the birds use it, you know, it's very suitable habitat for, like, many shorebirds, you know, on the coast or whether it's a little bit more inland. Lots of ducks and geese as what Bryan said, you know, like them emperor geese and spectacled eiders on the Yukon Delta. One of the subpopulations that is greater in numbers that nest here is here on the delta, so it's really good suitable habitat for species that are even, you know, that are a population of concern.
KYUK: In thinking about factors outside of avian flu and hunting [or] harvest, as you've mentioned, are there other major pressures on these populations?
Friendly: Yeah, so one of the species which I studied is the spectacled eider. The main factor that drives their adult survival is the ice conditions of where they winter, and they went through south of St. Lawrence Island at the Bering Sea. So, you know, these are tough, tough ducks that can withstand harsh winters in harsh environments. And so far they went to, there's like, you know, in the Bering Sea, and the reason why they're there is because, you know, they, they like to follow the food resources or the food that they obtain, which is like clams, mollusks, invertebrates, stuff like that. And when there's a lot of ice cover, it will prevent them to be able to forage, you know, to the, kind of to the benthic floor. They won't have, they won't get enough reserves or nutrients, which therefore, you know, may not let them nest or not just not doing so well, but also if the seat if there's sea ice, adult survival was somewhat low as well. But the reason for that it's not very, very well understood yet. But we say if there's, like, some sea ice and or no sea ice that’s like an ideal condition. So other areas like, or some factors during the offseason can really affect their population or any survival parameters.
KYUK: Anything you'd want to add?
Daniels: Yeah, just he touched on it a bit – just climate change in general, you know, the Yukon Delta is very low-lying. And so, you know, melting of polar ice caps, increased ocean levels flooding the nesting areas of a lot of these species is something we're looking at and trying to see what will happen, predict in the future of what may happen on the delta.
KYUK: We've just got, like, about a minute left. Is there anything else that you think is significant in what you've been looking at either this field season or more broadly that you'd want to touch on? It's a broad question, I know.
Daniels: Nothing directly in particular, just that, in general, most of the species are doing fine for harvestable species. And that we just hope people continue going out and following their subsistence rights and following regulations around the subsistence rights, the few that there are. And just a reminder that if anyone sees sick and dead birds out while they're subsisting to report it to the Sick and Dead Bird Hotline at 866-527-3358.
KYUK: Thank you very much for your time and good luck on your upcoming field research.
Daniels: Thank you.
Friendly: Thank you.
