Changes in Pacific Northwest white pelican populations puzzle scientists

White pelicans are distinctive. Their 9-foot white wings are black tipped, and can create a bit of a mirage when they fly, seemingly appearing and disappearing as they go. Some observers have mistakenly reported them as UFOs. The birds also have notable long orange beaks and the largest wingspan of any other bird in Oregon.

Their populations have increased considerably over the past few decades, and more recently, some pelicans have been spotted staying along the coast and in the Columbia River Basin for longer than expected. Scientists would like to know more about why and what the implications could be for the wider ecosystem. We learn more about white pelican colonies in the Pacific Northwest and how climate change may factor into the health of these birds from James Lawonn, an avian biologist at the Oregon Department of Fish and Wildlife.

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

Dave Miller: From the Gert Boyle Studio at OPB, this is Think Out Loud. I’m Dave Miller. White pelicans are distinctive, with 9-foot wingspans – the longest of any bird in Oregon – and pointy orange beaks. Their black-tipped white wings can even create a bit of a mirage when they fly, seemingly appearing and disappearing as they go, leading some observers to report them as UFOs.

After big population declines in the 20th century, their numbers in the Northwest have actually increased considerably over the last few decades. More recently, as written by Josephine Woolington in the Columbian Insight, some of these normally migratory birds have been sticking around to overwinter around the Columbia River.

James Lawonn is an avian biologist with the Oregon Department of Fish and Wildlife. He joins us to talk about white pelicans. It’s great to have you back.

James Lawonn: It’s great to be here.

Miller: How are white pelicans different from brown ones, besides their color?

Lawonn: Oregon’s got two different pelican species. The California brown pelican, strictly a marine species, is quite a bit smaller than American white pelicans. American white pelicans, on the other hand, are much more of an interior species. In fact, historically, they only nested in the interior portions of the American West, including Oregon.

Miller: What happened to white pelican populations over the course of the 20th century?

Lawonn: Well, white pelican populations declined quite a bit throughout the 19th century, even into the late 18th century. And that was a result of habitat loss, persecution in some cases, water diversion. Pelicans are colonial waterbirds, so they nest on islands on lakes. If you divert water from lakes or wetlands, they don’t have a place to breed anymore and …

Miller: Colonial, meaning they live in big colonies?

Lawonn: Yeah, exactly.

Miller: OK. But then in recent years, as I noted in my intro, some Oregon colonies have grown. So what’s behind that?

Lawonn: Colonies in Oregon that have grown … in particular, there’s one which is in the Columbia River Basin, in the Columbia River Estuary. And basically, pelicans, like all birds, need a few things to get along. One of those is breeding habitat and, in this case, it’s nesting islands. There’s more islands in the Columbia River Estuary than there used to be and that’s because of dredge material deposition.

Miller: Why do they like islands?

Lawonn: Oh, they like islands because predators can’t get to them. So colonial waterbirds in general, there’s a lot of birds all in one area, right? And that will attract predators. In order to stay away from predators, you go to a spot where predators can’t get to you, like an island surrounded by miles of water.

Miller: I’ve read that these birds can weigh as much as two bowling balls, which is a fun comparison.

Lawonn: [Laughter] Yeah, I think I came up with that.

Miller: OK, so who wants to eat them and who can eat them? I wouldn’t mess with a pelican, a 9-foot wingspan.

Lawonn: It’s more the chicks, right? It takes several months to grow a pelican chick, and pelican chicks are relatively defenseless. So if you’re a coyote, you’re not going to have any problems taking out a pelican chick. The adults are a different story. But adults, of course, can fly; pelican chicks can’t.

Miller: OK, so you were saying that in this one colony in particular, on the Columbia River, their numbers are on the rise. But what are the global reasons or regional reasons for that? I mean, are they coming here from somewhere else?

Lawonn: Yeah, there are a few things going on here. One, and there’s some debate or some uncertainty about exactly why this is occurring, but across the American West, white pelican numbers have increased by about twofold since the early 1980s. Part of that is probably related to increased habitat protections. But another thing is that pelicans are moving around in response to changes on the landscape that are related to climate change.

For example, some of the larger pelican colonies across the West have been affected by drought in recent years. The most notable example is Great Salt Lake, where several thousand pelicans nest annually – about 10,000. That colony failed in 2023. And if you’ve got 10,000 pelicans out of a colony that fails, these are birds that can easily move across the landscape. Flight doesn’t cost much energy for them. So we did see pelicans showing up in 2022 and 2023 along the coast, that potentially was related to failure at the Great Salt Lake colony and colonies elsewhere, including colonies in Oregon, such as one on Malheur Lake.

Miller: So they seem like pretty adaptable birds.

Lawonn: Yes, insofar as they have good breeding habitat – again, usually islands – and a lot of fish. Each bird eats 4 pounds of fish a day.

Miller: Wow.

Lawonn: So these are birds that weigh up to 30 pounds. They can really have huge energetic demands. They really need to eat a lot. If you’ve got a colony of 2,000 pelicans, you’re literally talking tens to hundreds of tons of fish every breeding season. So, yeah, these are factors pelicans are looking for when they decide where to live.

Miller: What do they like to eat in terms of fish?

Lawonn: Well, mostly, the pelican diet is composed of fish that are not of economic importance or conservation importance. Common carp are a really big part of the diet, for example, in Malheur Lake and some other areas. Common carp are a non-native species and it’s great that pelicans like to eat them. But pelicans can also eat fish that biologists are really concerned about. Some of those fish would include salmon and steelhead that are listed under the Endangered Species Act, so ones that we’re really worried about persisting into the future.

Miller: How big a concern is that? I mean, if more of these birds are going to be sticking around for longer, how big a concern is it that they would actually eat endangered or threatened salmon species here?

Lawonn: I think the epicenter of concern for salmon and steelhead in Oregon, really the Pacific Northwest, is the Columbia River Basin. There are two American white pelican colonies there, and there has been some research associated with pelicans there. For some runs of salmon and steelhead that are listed under the Endangered Species Act, there’s very little impact. But we’re just learning now that there are potential impacts for some runs of fish that haven’t been as well studied, and it’s not just juvenile fish that pelicans can eat. We recently have learned that pelicans can eat adult sockeye salmon. So these are salmon that sometimes weigh 3-4 pounds and pelicans can eat an adult. That can be really important from a conservation point of view, because if an adult makes it to the river, we usually expect that that adult would be able to spawn to create future generations of fish. But if pelicans eat them before they’re able to spawn, that can be a really bad thing for fish conservation.

Miller: What are the other big questions that you and other avian biologists have right now in the Northwest about these pelicans?

Lawonn: Yeah, so a big one is, how are they gonna weather climate change? Four out of five historical colonies in Oregon are on the dry side of the state, on the east side of the state. And all of those colonies have been affected by recent droughts. In fact, only 16 breeding pairs were present in 2022, and that was the last year that the state’s pelican population was surveyed. So yeah, climate change can be a big factor here for pelican conservation.

Miller: James Lawonn, thanks very much.

Lawonn: Thank you.

Miller: James Lawonn is an avian biologist with the Oregon Department of Fish and Wildlife.

Contact “Think Out Loud®”

If you’d like to comment on any of the topics in this show or suggest a topic of your own, please get in touch with us on Facebook, send an email to thinkoutloud@opb.org, or you can leave a voicemail for us at 503-293-1983. The call-in phone number during the noon hour is 888-665-5865.