Botulism outbreak threatens wild birds in Klamath Basin

A large botulism outbreak in Klamath Basin wetlands could kill more than 100,000 waterbirds if more water is not sent to the wetlands. The Bird Alliance of Oregon is asking the Bureau of Reclamation to release the water to the Klamath National Wildlife Refuges and says if there is no intervention, the die-off could surpass the one in 2024 when 140,000 birds were killed. We talk with Teresa Wicks, Eastern Oregon biologist with the Bird Alliance of Oregon, to get more details.

Note: The following transcript was transcribed using AI and validated for accuracy, readability and formatting by an OPB volunteer.

Geoff Norcross: This is Think Out Loud on OPB. I’m Geoff Norcross in for Dave Miller. Two years ago, 140,000 birds died in the Klamath National Wildlife Refuge complex that straddles the Oregon-California border. It was an avian botulism outbreak that took the birds, and it’s happening again. Conservation groups say conditions are right for a botulism outbreak to kill even more migratory birds, and they’re asking the federal government to release more water into the system to prevent this. Teresa Wicks is a biologist with the Bird Alliance of Oregon, and she joins us now. Teresa, welcome to Think Out Loud.

Teresa Wicks: Thanks. Happy to be here.

Norcross: Can you set the scene for us first? What kinds of birds are there in the refuge? What kinds of species? How many of them?

Wicks: Oh, how many species is maybe a potentially loaded question. This time of year, it’s an interesting time of year because for some species of birds, like shore bird species, this is when migration starts. So we have a mix of various breed species, duck species, and a handful of shorebird species that nest here, and now we’re also starting to see the arrival of migrant shorebird species. So there are probably a dozen waterfowl species, and waterbird-wise, there are probably another seven to ten species, and then you add in shorebirds and pelicans and it gets complicated pretty fast… and it depends a little bit on where you are in the basin.

Norcross: Ok, so lots of different birds there for lots of different reasons. I get that. What is it about this place that makes it important, and why is it a good place for them to be?

Wicks: It’s really interesting, because if you look at a map of the Pacific Flyway, which is essentially the region between the Rocky Mountains and the Pacific Ocean, a lot of the birds that are migrating east of the Cascades, especially water birds, at some point in their journey seem to stop in the Klamath Basin. And in part that’s because of its position in the basin. It’s pretty well situated between other water bodies that birds can stop over and forage in, but it also, historically, had about 300,000 acres of wetlands in it. So from a species perspective, they have that generational connection to the place. The basin is just a place that birds have stopped for generations and generations, and so some of what we see is that importance, because it has always been important, and some of what we see is that it is often one of the only places with water between other stopover sites where birds can refuel.

Norcross: So there aren’t a lot of other water options for the migrating birds. I get that. What is happening there now that concerns you?

Wicks: The first thing to note is that botulism is naturally occurring in our Oregon soils and in soils across most of the globe, so the background level of botulism has always been something that might kill a few birds but doesn’t produce large die-offs. 2020 was the first year we saw a large die-off happen in the Klamath Basin, and that killed 60,000 birds, and in 2024, we had another large die-off that, as you mentioned, killed 140,000 or more birds. This year, two years later, we’re seeing botulism. The refuge is picking up around 150 dead birds a day, which for this time of year is high.

When botulism outbreaks happen historically, they would start later in the year, typically after this year’s baby birds have fledged or are able to move on. This year, it’s starting pretty early. We still have baby grebes that are hatching, and ducks on nests, because the conditions have been good for an extended breeding season. So we have this, it’s almost a trifecta of low water conditions to encourage more breeding, and birds are starting to arrive to molt, and the water levels are now dropping to where the botulism can start to reproduce and start that botulism cycle. So the potential for a really large die-off is there.

Norcross: So if I’m hearing you correctly, botulism is there naturally, but water, when there’s enough of it, acts as kind of a protective layer between the pathogen and the birds?

Wicks: Yeah, botulism tends to thrive most in shallow water, like less than three inches, and stagnant water. It needs it to be warm, stagnant, low oxygen, and typically that means also not very deep. That’s where the bacterium can start to release spores. The spores are what get ingested by birds or insects that, when they get botulism, and other things eat them, it kind of creates that snowball cycle, where the more things that are eating species that have been impacted by botulism, the more the botulism spreads.

Norcross: OK, so what needs to happen?

Wicks: Last year was a pretty good example of how water can be used to keep botulism from exploding like it has the potential to right now. There was some botulism here last year. Tulelake Irrigation District was able to work with the refuges to keep water moving into the area of Tulelake where the botulism was happening, and they were able to keep that outbreak from expanding and becoming something really big.

This year, it’s early enough in the botulism outbreak where there is potential to essentially reflood those exposed mud-flat type areas, areas where the botulism can thrive, getting more water into them would help to essentially suppress the ability of the botulism to persist this year.

Norcross: Who is in charge, who could make the decision to actually reflood those areas?

Wicks: That is a really complicated question. My answer is gonna be maybe unsatisfying, but I think it needs to be a collaborative effort between… Bureau of Reclamation is the one that essentially says how much water is going to be diverted from Upper Klamath Lake for irrigation, for the ag community, and then also for the refuges. This year, they essentially lumped that together and just said this is how much water is coming from the lake. And so the situation right now is that it needs to be a joint effort between the Bureau of Reclamation, water users and the tribes to figure out where that water can come from.

Norcross: Do you get the sense that the current Bureau of Reclamation under this federal government is sensitive to the concerns that you’re raising?

Wicks: I had a conversation with the director for Region 10, and he seemed happy to have a conversation. I think he wants to be able to find a solution, I think that people want there to be a solution. I think the solution is always hard to get to because it requires a collaborative effort, but outside of that brief conversation, we haven’t received any notification about whether or not water is coming. But I think people are amenable to having the conversation.

Norcross: Teresa, you touched on this, and that is that in this part of the world where water is a scarce resource, there are a lot of stakeholders too. You mentioned wildlife, you mentioned agriculture, but also tribes get their allocations, too, and I’m wondering how you balance all these needs for water in this place?

Wicks: I think that right now what we’re seeing is that the system is actually pretty out of balance, and that is why the botulism outbreaks have become such a problem. The sucker populations are not doing well in Upper Klamath Lake. Right now their prognosis is pretty bleak. I think the water quality issues in the rivers and the lake, and the issues for the sucker populations and the botulism outbreaks, are all signs to me that actually the system isn’t being balanced very well, and I think there are some really interesting collaborative ideas to try to essentially bring the system back into a better balance.

They’re being generated from within the community, because I think people are starting to see that fighting, especially through courts and whatnot, rather than working together, isn’t actually bringing the system into balance. It’s not actually benefiting anybody, and I think there seems to be a pretty clear interest in the community to try to find some balance.

Norcross: You mentioned you’re losing 150 birds a day, and the die-off could exceed the one in 2024 when 140,000 birds died. I have to imagine there are ripple effects from this. It’s not just bad news for the birds. Can you talk about how a die-off like that can affect the greater ecosystem?

Wicks: Yeah, we don’t talk a lot about other species that potentially are impacted, in part because, like, coyotes are a good example. Coyotes frequently scavenge the birds that die from botulism. We don’t know for sure how they are impacted by botulism. There is a pretty high risk that they could be impacted by it, but even turkey vultures, ravens, the other scavenger-type birds whose job is to help be nature’s cleanup crew, they are impacted by botulism. So it expands out, not just from the water birds, but out into other species that potentially are consuming them.

And then from a flyway perspective, water birds and waterfowl in the Pacific Flyway are declining throughout the flyway. And when we have these big outbreaks here, it doesn’t just impact birds that are here, because the birds that are here, molting here, are birds that would have been nesting farther north, and then potentially would have gone down to winter in the central valley or down in Southern California or Mexico. So you start to see the impacts on bird communities and avian ecology, essentially throughout the entire flyway, because of birds dying off here, if that makes sense.

Norcross: Yeah, it does. Thank you for making those connections for me and thank you for joining us on the program. I really appreciate you coming on.

Wicks: Yeah, thanks for having me.

Norcross: Teresa Wicks is a biologist with the Bird Alliance of Oregon.

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