The Current - Bird populations are in steep decline, study suggests

Episode Date: May 12, 2025

Bird populations across North America have fallen by billions over the last 50 years, according to a staggering report from Cornell University. Researcher Amanda Rodewald explains what’s happening, and why common birds like sparrows, blackbirds and finches are suffering the greatest losses.

How did the internet go from this? You could actually find what you were looking for right away, bound to this. I feel like I'm in hell. Spoiler alert, it was not an accident. I'm Cory Doctorow, host of Who Broke the Internet from CBC's Understood. In this four-part series, I'm going to tell you

why the internet sucks now, whose fault it is, and my plan to fix it. Find Who Broke the Internet on whatever terrible app you get your podcasts. This is a CBC Podcast Red Winged Blackbird. If you feel like you're hearing its song a little less these days, you might be right. The numbers of Red Winged Blackbirds are in decline across North America. Just one of nearly 500 birds that Cornell University's Ornithology lab looked at in a new study.

The findings in that study paint a dire picture. 75% of all bird species in North America are in decline. The drops in population also happening fastest in areas where birds were usually most abundant. Amanda Rotewald is an author of the study, Senior Director of the Center for Avian Population Studies at Cornell University's Lab of Ornithology. Amanda, good morning. Good morning, Matt. It's great to be here. It's great to have you here. Studies at Cornell University's Lab of Ornithology. Amanda, good morning.

Good morning, Matt. It's great to be here. It's great to have you here. This is the time of the year when, as I said, people are waking up to the sounds of the dawn chorus of birds that are chirping in the morning, the spring migration is underway, birds should be arriving, and yet these numbers, as I say, 75% of bird species in decline sound bad. How bad is it? Yeah, it is something that we need to really focus on. So over the last five or six years, we've seen a series of reports that have alerted us to these widespread and, as you say, oftentimes steep population declines across North America. So this recent paper in Science, it really uses a different and sharper lens because

we're taking data from eBird that allow us to really pinpoint in fine detail precisely where these population declines have been occurring recently, so since 2007. And so, yeah, we're finding that these range-wide declines occur, but that we are able to detect now, for the first time, those pockets where we can really focus our conservation efforts. So it's actually giving us some power. You mentioned eBird. I mean, this is citizen science, right?

A lot of the findings that you're pulling here are from data that was gathered by the sightings of birds that people themselves found and then put through this app. Yeah, it's wonderful. As you say, this is really a global participatory science project that's fundamentally a partnership with bird organizations around the world. Birds Canada and Quebec Wazoo have been partners

from the start. And so since 2002, volunteers have submitted almost 2 billion observations from every country in the world. And so those 1 million contributors to eBird are actually helping to fuel science, wildlife and environmental management and help decision makers make choices better that really help support both people and the planet. Where are you seeing the steepest decline in bird populations? Well, we see them, if you look across species groups,

grassland birds and shorebirds have declined most severely. When we look across, you know, across the ranges of these different species, what's really most striking and frankly most alarming is the ranges of these different species, what's really most striking and frankly most alarming is that most of these declines are steepest in the species strongholds. So these are the places where they're most abundant and where we generally expect them to thrive.

So although there are many different reasons that might contribute to this pattern, what it does tell us is that we need to be aware that environmental conditions seem to be deteriorating. And obviously we care about that for birds, but we share those same environments with those birds. One of the birds that people have pointed to that is in precipitous decline is the great blue heron, which is a

majestic bird. What in particular is happening with the herons? Yeah, so great blue herons with many other species that are dependent upon wetlands and waters, like the red-winged blackbird that you featured at the start of the story, we're losing wetlands. We continue to convert them to agriculture or development. They're also can be degraded by soil erosion, you know, sedimentation, chemicals that flow into those areas.

So, and climate change, things like droughts, you know, that are more severe these days. So, many different factors tend to contribute to the declines we see. What's happening with avian influenza? That seems to be, I mean, we talk about that in terms of how it's impacting bird populations in flocks of chickens and turkeys and what have you, but it also is impacting migratory patterns as well, right? Well, so this study did not focus on avian influenza

in particular, we're more describing these patterns of declines. However, there are many scientists who are studying avian influenza in particular, we're more describing these patterns of declines. However, there are many scientists who are studying avian influenza. We know that it does disproportionately affect some groups of really strong conservation importance like seabirds, for example. So that is a situation that is continuing to be studied that we do have to worry about, both for human health and for certain bird populations.

But if you're talking about, so in the populations of shorebirds or in grassland birds and in birds around marshlands, how much of this is our fault? I mean if you're talking about, you know, the impact of development or the degradation of those environments. I mean ultimately most of the changes we're seeing, so whether it's due to habitat loss and degradation, which is the biggest driver of decline, or even indirectly through climate change, we are, human activities are the biggest factor that's affecting species. But I will say, like, I mean, of course,

we need some of these activities to persist, and that's why programs like eBird that are providing more information than ever about birds and the environments we share with them are really game changers because they're empowering us to be more precise in our actions, act more quickly, be more proactive.

And ultimately that means we'll be less restrictive to a lot of the activities that sustain livelihoods and communities and strong economies. What is it that we can do if we are responsible for this? What is it that we can do to help turn those numbers around? I think looking at a very strategic early look at where we can, for example, cite some of these human activities, where we're citing renewable energy projects. You know, there are ways to accommodate, where we're avoiding the most important places

for biodiversity that many times are actually also supporting the ecosystem services that safeguard human health and well-being. So again, with information, we can make better choices. Much more broadly, from a sort of civics perspective, we need to always be supporting conservation organizations, government agencies who are charged with protecting these systems, you know, and express that,

whether at the ballot box or with donations or with just supporting and participating in projects like eBird. Is your sense that people are paying more attention to this now? We're going to hear a conversation with Ed Yong coming up in a moment, who never paid much attention. He's fascinated with the natural world, but didn't pay a lot of attention to birds until after the pandemic. And in part, his introduction was through the Merlin bird identification app that Cornell is so deeply responsible for. Is your sense that people are paying more attention to this issue now,

that that might help lead the change that you're talking about? Absolutely, Matt. Yeah, when we look at it right now, there was a study at least done in the US showing half of American adults watch or feed birds. And so, I know in Canada, there are of course lots of really passionate birders as well. And so that engagement is important. That engagement for one also sends strong economic signals because these birds are generating a lot of activity, economic activity. So even people who don't care about birds matter.

But I think that the interest in birds also helps to make people generally more aware that the same actions we need to take to conserve birds are in fact the same ones we should be taking to protect human health and well-being. And so we're seeing more and more that it's not a question of do we help birds or do we help people, but really it's how best do we serve both groups. And thanks to birders who generously contribute their observations to programs like eBird, we have more and better information to do that than ever. Amanda, thank you very much for this.

Thank you, Matt. Amanda Rotewald is a senior director of the Center for Avian Population Studies at Cornell University's Lab of Ornithology. This has been The Current Podcast. You can hear our show Monday to Friday on CBC Radio 1 at 8 30 a.m. at all time zones. You can also listen online at cbc.ca slash The Current or on the CBC Listen app or wherever you get your podcasts. My name is Matt Galloway. Thanks for listening. For more CBC podcasts, go to cbc.ca slash podcasts.