North American Bird Populations Plunge 30% Since 1970

By Jerri-Lynn Scofield, who has worked as a securities lawyer and a derivatives trader. She is currently writing a book about textile artisans.

Science magazine Thursday released a study, Decline of the North American avifauna, documenting a nearly 30% drop in North American bird populations since 1970.

That translates to a loss of nearly three billion birds.

The study has been widely reported, and even ornithologists have been shocked by the extent of the decline. The New York Times reports in Birds Are Vanishing From North America:

“We were stunned by the result — it’s just staggering,” said Kenneth V. Rosenberg, a conservation scientist at Cornell University and the American Bird Conservancy, and the lead author of the new study.

“It’s not just these highly threatened birds that we’re afraid are going to go on the endangered species list,” he said. “It’s across the board.”

An account in the Cornell Chronicle, Nearly 30% of birds in U.S., Canada have vanished since 1970, connects the dots:

Rosenberg said the results of this study point to something bigger than birds.

“It’s a strong signal that our human-altered landscapes are losing their ability to support birdlife,” he said. “And that is an indicator of a coming collapse of the overall environment.”

Science also published a precis, Three billion North American birds have vanished since 1970, surveys show, which notes:

“I frankly thought it was going to be kind of a wash,” Rosenberg says. He expected rarer species would be disappearing but common species would be on the rise, compensating for the losses, because they tend to be generalists, and more resilient. Indeed, waterfowl and raptors are thriving, thanks to habitat restoration and other conservation efforts. But the declines in many other species, particularly those living along shorelines and in grasslands, far exceeded those gains, Rosenberg and his colleagues report. Grassland birds have declined by 53% since 1970—a loss of 700 million adults in the 31 species studied, including meadowlarks and northern bobwhites. Shorebirds such as sanderlings and plovers are down by about one-third, the team says. Habitat loss may be to blame.

The familiar birds that flock by the thousands in suburbs were not exempt. “There’s an erosion of the numbers of common birds,” Rosenberg says.

From the text of the full paper:

More than 90% of the total cumulative loss can be attributed to 12 bird families (Fig. 3A), including sparrows, warblers, blackbirds, and finches. Of 67 bird families surveyed, 38 showed a net loss in total abundance, whereas 29 showed gains (Fig. 3B), indicating recent changes in avifaunal com- position (table S2). While not optimized for species-level analysis, our model indicates 19 widespread and abundant landbirds (including 2 introduced species) each experienced population reductions of >50 million birds (data S1). Abundant species also contribute strongly to the migratory passage detected by radar , and radar-derived trends provide a fully independent estimate of widespread declines of migratory birds.

Our study documents a long-developing but overlooked biodiversity crisis in North America—the cumulative loss of nearly 3 billion birds across the avifauna. Population loss is not restricted to rare and threatened species, but includes many widespread and common species that may be disproportionately influential components of food webs and ecosys- tem function. Furthermore, losses among habitat generalists and even introduced species indicate that declining species are not replaced by species that fare well in human-altered landscapes. Increases among waterfowl and a few other groups (e.g., raptors recovering after the banning of DDT) are insufficient to offset large losses among abundant species (Fig. 3). Importantly, our population loss estimates are conservative since we estimated loss only in breeding populations. The total loss and impact on communities and ecosystems could be even higher outside the breeding season if we consider the amplifying effect of “missing” reproductive output from these lost breeders. [citations omitted]

Over to the Cornell Chronicle:

“We want to keep common birds common, and we’re not even doing that,” said Peter Marra, a study co-author who contributed to the analysis in his former position as director of the Smithsonian Migratory Bird Center. Marra is now director of the Georgetown Environment Initiative.

“Put that into the context of the other declines that we’re seeing, from insects to amphibians, and it suggests that there’s an ecosystem collapse that should be troubling to everybody,” Marra said. “It’s telling us that our environment is not healthy. Not for birds, and probably also not for humans.”

Having enjoyed some remarkable birding in Canada – including visiting Churchill, Manitoba, during the golden plover’s breeding season, watching (from a boat) oodles of puffins — aka a “circus” or “puffinry” – nesting in Newfoundland, and participating in Christmas bird counts in Whistler, British Columbia, I want to highlight that the study’s finding that  the decline extends beyond US borders to Canada as well. According to CBC News, N.S. bird watchers shocked by ‘staggering’ bird declines:

“This is not just North America,” [Lucas Berrigan, who works for Bird Studies Canada,] said. “There is a global crisis and I think we need to… take this more seriously than we have previously.”

“Barn swallows, chimney swifts and nighthawks, as well as seabirds, storm petrels in particular, these are birds that are usually out of sight of most people, but they are of a significant importance ecologically,” Berrigan said.

“We’ve seen quite large declines in those populations. The largest population of one of these seabirds has declined nearly 50 per cent in the past 35 years.”

Others impacted include backyard birds, warblers, finches, sparrows and songbirds, as well as long distance birds like swallows and sandpipers that come to Canada from the Arctic.

Berrigan noted that another recently published paper spoke about how neonicotinoid — a pesticide — is affecting bird migration.

“In short, they lose a significant amount of body fat when feeding on seeds treated with very small amounts of [neonicotinoids],” he said.

“Body fat is extremely important for migratory birds since it determines how far they can fly at a given time.”

Causes of Bird Population Decline

The principal causes of the decline are well-known: habitat loss, and pesticide use, which intentionally decimates insect populations.

The Grey Lady reports:

Grassland species have suffered the biggest declines by far, having lost 717 million birds. These birds have probably been decimated by modern agriculture and development.

“Every field that’s plowed under, and every wetland area that’s drained, you lose the birds in that area,” Dr. Rosenberg said.

Rachel Carson’s classic, Silent Spring, originally serialised in The New Yorker in 1962, attracted notice from President John F Kennedy, and ultimately, helped catalyse a ban on DDT. The chemical had destroyed populations of raptors, including the iconic American bald eagle. The latest study is yet one more example showing that the lessons Carson conveyed, alas, have been forgotten.

What Is To Be Done?

Absent immediate and targeted conservation activity, bird populations will continue to decline.  The paper pointed out that extinction of even common species – such as the passenger pigeon – can occur rapidly:

Extinction of the Passenger Pigeon (Ectopistes migratorius), once likely the most numerous bird on the planet, provides a poignant reminder that even abundant species can go extinct rapidly. Systematic monitoring and attention paid to population declines could have alerted society to its pending extinction. Today, monitoring data suggest that avian declines will likely continue without targeted conservation action, triggering additional endangered species listings at tremendous financial and social cost. Moreover, because birds provide numerous benefits to ecosystems (e.g., seed dispersal, pollination, pest control) and economies (47 million people spend 9.3 billion U.S. dollars per year through bird-related activities in the U.S.), their population reductions and possible extinctions will have severe direct and indirect consequences . Population declines can be reversed, as evidenced by the remarkable recovery of waterfowl populations under adaptive harvest management and the associated allocation of billions of dollars devoted to wetland protection and restoration, providing a model for proactive conservation in other widespread native habitats such as grasslands. [citations omitted]

When faced with such devastating news, pleas for conservation may appear Panglossian. Yet that’s not entirely so. Rosenberg provided some grounds for cautious optimism, according to the Cornell Chronicle: :

There are a few bright spots for birds. Among the population models, raptor populations – hawks, eagles and other birds of prey – have tripled since 1970. The study’s authors said that uptick is attributable to government regulations that banned the harmful pesticide DDT and made shooting raptors illegal.

Waterfowl populations have grown 50% in the past 50 years. The scientists said that’s due to dedicated programs such as the North American Waterfowl Management Plan and its billions of dollars invested into wetlands conservation and international collaboration, as well as the establishment of a federal no-net-loss wetlands policy.

Rosenberg, a faculty fellow at the Atkinson Center for a Sustainable Future, said the success in wetlands conservation for waterfowl may provide a blueprint for turning around the steep declines among grassland birds. Even if 30% of North America’s birds are lost, there are still 70% left to spur a recovery if conservation measures can be implemented. But conservation action must come soon, he said.

“I don’t think any of these really major declines are hopeless at this point,” Rosenberg said. “But that may not be true 10 years from now.”

Andrew Holland, a spokesperson for the Nature Conservancy of Canada, concurs on the need for conservation and connects climate change to habitat loss. He also mentions the role played by free-roaming domestic cats. Over to the CBC:

“When you look at those numbers, clearly it’s a signal that there needs to be more conservation of lands that protect the habitats for the birds that are remaining so that they have a fighting chance of bouncing back.”

Habitat loss and climate change are among the major factors impacting the decline of bird populations.

Free-roaming domestic cats, collisions with glass, pesticide use and a decline in insects are also factors, he said.

Holland suggested that people leave their cats indoors.

“A lot of lands have been lost — wetlands, forests, coastal shoreline areas have been lost to erosion, storm surges, development and subdivisions,” said Holland.

So, in addition to the other massive catastrophes we must address – climate change, plastics, to name just two – add bird conservation measures to the list. The roots of each:  untrammelled consumption. We know what must be done. Are we up to the task? Over again to the NYT:

The sheer scale of the bird decline meant that stopping it would require immense effort, said [Hillary Young, a conservation biologist at the University of California, Santa Barbara, who was not involved in the new research]. Habitats must be defended, chemicals restricted, buildings redesigned. “We’re overusing the world, so it’s affecting everything,” she said.

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  1. DJG

    What’s going on here is human-caused disaster: Now, from our vantage point of “how benighted other times were,” we wonder at killing egrets and other birds for their feathers for hats. The barbarous practices of other eras.

    Instead, we now engage in “soft” denial of climate disruption. Yet this symptom is unavoidable. Waiting for the barbarians? It turns out that they are us.

    My prediction: Gumming the data to death on the Anglophone WWW. I don’t see any action to remediate this crisis coming from the United States.

    And asking people to keep the cat indoors? What cheek!

  2. Carolinian

    The passenger pigeons were blasted out of the sky were they not?–sort of like what happened to the buffalo.

    I’ve just been reading some of Mark Twain on his Hannibal boyhood and he says they would harvest the pigeons by knocking them out of the trees, not even using guns.

    And while it isn’t clear what can be done there is this

    Andrew Holland, a spokesperson for the Nature Conservancy of Canada, concurs on the need for conservation and connects climate change to habitat loss. He also mentions the role played by free-roaming domestic cats. […]

    Holland suggested that people leave their cats indoors.

    Other suggestions include attaching bells to their collars.

    1. HotFlash

      The passenger pigeons were blasted out of the sky were they not?–sort of like what happened to the buffalo

      It wasn’t just for ‘sport’, you know. Passenger pigeons were slave food.

    2. John

      Somehow I’m not surprised that an NGO with a bunch of oil and gas executives on its board is trying to tell us that domestic cats is a cause of this mass extinction. How about we stop burning fossil fuels so that the planet stops heating up? How about we stop using pesticides that are killing off all of the insects, which are the main source of food for many birds? I mean roaming domestic cats is far down on the list of things causing the current situation that it is ridiculous that they would even devote any words to it. TNC should focus on getting rid of its own ties to the polluters that are destroying the planet.

  3. sangell51

    I live on Sarasota Bay in Florida and while not a big fan of marine birds ( they soiled my boat and they aren’t ‘songbirds’) I moved into their habitat so I had no choice but to accept their ‘droppings’ and noise. Last year we had a severe ‘Red Tide’. Cause not known but fertilizer run off suspected but it killed all the fish and damn near ever marine bird from St. Petersburg down to Fort Myers. The water smelled and not just from dead fish. It was very alarming. The good news is that a year later the fish and birds are back. Maybe not in the same numbers but nature is resilient if we give it a chance.

  4. Rod

    You want to see the species causing all this???

    You look hard into the mirror —you will not see a cat

    Imo–if I, and you, are not actively–right now actively–being part of the solution then we–me and you–are the first problem…

    1. Carolinian

      you will not see a cat

      You will see the owner of a cat? In my neighborhood–mostly dog owners–some cat owners let their cats roam free to the point that they take up with different owners. They are effectively feral. Everyone here at NC loves cats of course, but the sad truth is that they do kill a lot of small birds.

      And birds kill lots of birds too. Hawks like it where I live.

      1. Darius

        Cats are songbird vacuum cleaners. I used to have an outdoor cat in the city many years ago. The little monster killed loads of house sparrows. I didn’t mind because house sparrows were abundant and I thought of them as flying mice. I suppose they actually are completion though.

        Later, living in the suburbs, I used to chase cats away because we had diverse bird life, including the occasional towhee.

        Now, back in the city, I have developed a fondness for house sparrows and starlings. Better than nothing and interesting behavior.

    2. anon in so cal

      House cats let loose kill a huge number of birds each year in the US. The American Bird Conservancy says “Now numbering well over 100 million in the United States, cats kill approximately 2.4 billion birds every year in the U.S. alone, making cat predation by far the largest human-caused mortality threat to birds.”

      ABC has published summaries of studies of cat owners suggesting they are in denial about the impact of cats on birds.

      In my neighborhood there are signs now and then posted by owners looking for a lost cat, typically allowed out, and eaten by a coyote. Sounds barbaric but my thought is one less predator. I love cats and have had some beloved feline pets, but they belong indoors.

      Birds such as Cooper’s Hawks do also eat other birds but nothing in the numbers of cats.

      NYT had this article about Sydney, Australia, where the populace apparently very much appreciate birds. Have not read the article yet but it sounds as if the bigger birds are doing best which aligns with the Science article.

      Broken record here, but as with global climate change, human population growth is a driver.

      More housing subdivisions, more roads, more intensive agriculture, more pesticides, etc. all spell doom for birds.

    3. Art

      While I believe that the best solution to the bird problem would be to go after our evil industrial overlords and their malevolent practices, I’m pretty sure there is a lot of good science re. the detrimental impact cats have on birds and small animals and it’s pretty grim stuff. I’m a cat lover too and I believe it. They are adorable killing machines. And it’s not just our beloved pets doing it. Feral cat populations are also a big part of the problem. It’s good to be mindful of this if you are into the cat scene.

  5. marieann

    I have had cats all my life and the two I have now are my first indoor ones, all the others had been strays and I could not get them to give up the outdoors.It was around this time I started donating to a wildlife rescue group whose main focus was on rehabilitating birds, a couple of my kitties were really good hunters.

    They local shelter gives out spay/neuter vouchers for cats and feral cat carers…..this programme should eventually reduce the number of cats who have to hunt to eat.
    Feral cats are a human problem, one that we should work on solving for the cats and also for the birds.

  6. Dan

    Easiest thing you can do to help birds in general:
    Leave at least one out of the way brush pile in your yard, big enough for them to hide or nest in. Don’t touch approach it in nesting season.

    And of course, never spray anything toxic on your land.

  7. Bob


    We’ve been here before –

    Remember “Silent Spring” by Rachael Carson ?

    And by some accounts the Class Insecta is experiencing the same decline.

    How about we ban Neonectoids and Round up ?

    Can the bird and population insect data be graphed against the introduction and use of these items ?

    1. Sparrow

      Where I live it’s not only the so-called farmers but within one year after a huge cell tower went up outside a state park where i walk several times a week, not only the population of birds went drastically down but also wild animals. It is from understanding what these dangerous towers do along with destroyed habitats, and an ever increasing number of cars on the road has impacted our flora and fauna. Add to that increased hunting, increased human encroachment along with all their unsustainable doctrines of death. Humans have never accepted the idea to be part of the ecosystem instead of being apart from it. When they are gone, we are gone.

      1. drumlin woodchuckles

        All kinds of non-industrialized human nationloads of people understood themselves to be ecosystem-embedded co-ecosystem members. All the American Indian nations, for example.

        The Western European-based Industrial Civilization was the first major human Civilization which formally and overtly adopted ecosystem-hatred and deliberate ecocide as its Prime Directive. It is incorrect to conflate Westernismic Industrial Civilizationism for ” humans in general”.

  8. katenka

    I run a food growing/donation program at an organic community garden here in Chicago, and our garden is right next to a city park by the river (and so connected to a long, if sometimes rather narrow, line of green space running through the city). Our garden bugs and birds seem to be doing pretty well, but we keep trying to do better by them every year, because we know it’s really tough out there for them. We already give them lots of nice seeds and piles of old vegetation to play with, but one of our improvements this year is starting to replace some of the extra obnoxious weedy perimeter with more congenial natives and friendly imports who have invited themselves in and seem to play nicely with others. At any rate, some of our weed area is tree-shaded and some of it is more grassland-ish, and we get a fair number of sparrows and goldfinches. I see so many sparrows that it was something of a shock to realize that outside my little sparrow-friendly bubble, they’re really taking a hit. The goldfinches are more an ebb-and-flow population sort of bird, and this report on their struggles encouraged me to look up what I could do to help them best. I got a clear answer, although it wasn’t an answer I wanted: they adore thistles. Thistles, noooo, Canadian thistles make my life a living hell!!! But I found a nice native one (tall thistle, Cirsium altissimum) that doesn’t puncture you brutally if you touch it (thanks for that), and I am putting it in with my fall native plantings so that we can make a better goldfinch oasis next year and onwards. Thanks for posting this article as a prompt.

    And for anyone interested in planting flowers/natives for the birds and other critters in your yard or anywhere you think you can get away with it: fall is often a great time for that!!!

    1. anon in so cal

      The most reasonable places to get bags of nyger seed are HD and Lowes. They also have metal mesh cages of various sizes.

      1. katenka

        Bags of eating-seed for now, a thriving tall thistle population for next year and onwards! I’ll see whether I can get the other gardeners as excited about this (native!) thistle I’m planting as everyone was when I got the common milkweed going…it might be a tough sell at first, heh, but everyone does love the goldfinches.

    2. rd

      At the personal level, the actions you are taking are critical.

      Wailing about the Amazon burning doesn’t count if a person is mowing a large suburban lawn with non-native grasses with foundation plantings of non-native shrubs. The suburbs took over some of the most biologically productive land in the country.

      Similarly, the expansion of irrigation along with heavy pesticide and fertilizer use has cause the huge tall grass prairies to vanish under tilled farmland. Even the linear strips along roads and farmland borders that used to be filled with native herbaceous plants are now largely denuded or filled with non-native invasives.

      One of the solutions that individuals can provide is to plant native trees, shrubs, and herbaceous plants in their yards. When properly arranged, they provide food, cover, and nesting habitat essential to maintaining insect and bird populations. Unfortunately, the nursery and landscape architecture industries are still far behind where they need to be on this.

      1. katenka

        I do think that chemically-controlled turf-lawn culture is changing — whether it’s changing enough and fast enough, in such a large, complex system, I guess we’ll see! For a positive sign, the new garden center that opened locally specializes in organic kitchen garden type stuff and natives; what they promote most heavily re: natives is of course helping and attracting butterflies.

      2. Freshstart

        “Even the linear strips along roads and farmland borders that used to be filled with native herbaceous plants are now largely denuded or filled with non-native invasives.”

        I live in West central Minnesota. The farmers are having their way with roadside ditches. I don’t know if it is financial desperation or padding their pockets. We were already at the point where 40% of pheasants/other ground nesting birds were coming from these remaining strips of road side. But now thats disappearing too. And forget about the leopard frogs, they’re long gone.

        “A showdown over roadside mowing in rural Minnesota has unleashed a surprisingly passionate debate at the Legislature about the culture of farming, property rights and the desperate plight of bees and monarch butterflies.

        It’s put wildlife in a fierce — but so far losing — competition with Minnesota farmers..”

  9. Rod

    Sure, looking in that mirror one would see a human being that has enough hubris to think they are actually an “owner of a cat”. :-)
    Cats are as lethal to birds as coyotes to feral cats in ecosystems where they are the apex predators.
    However, Homo Sapiens is the most lethal predator overall:

    The Climate on earth which sustains us is convulsing directly because of human behavior.
    One particular behavior to note during the northern hemisphere avian migratory period is the ‘habit’ of Muncipalties allowing non critical infrastructure to remain illuminated throughout the night.
    The energy generated contributes to the carbon burden while simultaneously disturbing avian migratory systems.
    What a twofer-huh
    And brushpiles help, as a staggered height understory and, as in times of drought as I am now in again, a shallow basin of water placed off the ground.

  10. Watt4Bob

    When my daughter was young, we tried to find a copy of Rachel Carson’s Silent Spring, so she could do a report.

    We found out Silent Spring is one the most stolen books in the library, every library in the system.

    It seems moronic ideologues have an informal campaign to stop the spread of her ‘radical environmentalism’.


    1. drumlin woodchuckles

      If the ideomorons have an effective campaign to steal all copies of Silent Spring as soon as they are spotted, then perhaps ideomoron-busters should start an undisclosed stealth-campaign to buy copies of Silent Spring, soak them with poison ivy oil or maybe Polonium 210 or maybe a mixture of ricin and dimethyl sulfoxide . . . and then sneak them onto library shelves for the ideomorons to touch and pick up with their bare hands as part of stealing them.

  11. The Rev Kev

    “Canary in a coal mine”

    Canary in a coal mine (plural canaries in a coal mine or canaries in coal mines)

    1-(idiomatic) Something whose sensitivity to adverse conditions makes it a useful early indicator of such conditions; something which warns of the coming of greater danger or trouble by a deterioration in its health or welfare.

  12. Tyronius

    I just got back from the local grocery store, where I like to read an article or two in one of the magazines on the rack while waiting for friends to finish shopping. Today’s selection was a discussion be current issue of National Geographic about how many birds are killed by cats in America every year; nearly 3 billion! The author’s suggestion for helping to control this number seemed dubious; mandatory microchip implants in every pet cat. By way of coincidence, that article said that the only invasive species more destructive than the housecat was the one in the mirror. Seems we’re all thinking the same thing. The climate remediation crowd wants to set aside land to return to ‘uncultivated’ forest, as distinct from growing trees to cut down for various uses. It seems evident that such a wild lands conservation approach would create a great deal of just the right sort of habitat to help support the recovery of bird populations.

    1. a different chris

      Yeah we blame the cats but the cat comes with the sprawl and how many birds can nest on a McMansion roof with what little grass there is soaked in pesticides? I emphasize nest because Nature is actually not bad – not perfect, especially when it comes to cats, but not bad – at coming to stasis.

      So keeping your cat indoors and sneering at those who don’t, when you and your neighbors just wiped out 100 acres of habitat seems a bit precious.

      1. Furies

        Oh, well, then.

        If that ‘other guy’ is doing bad stuff it excuses your own contribution?

        “Yeah, but look at those guys!”

      2. drumlin woodchuckles

        The suburb I grew up in had normal one-story houses and biggish yards and lots of nesting birds.
        Many suburbs are like that. In such suburbs, bird-killing cats would find lots of birds to kill.

        Are you an ornithocidal cat-keeper by chance?

        1. a different chris

          Yes I am confess to the ownership of one of the most ecocidal cats ever. I also have 30 acres of woods, he isn’t making a dent. And at some early point (3 years old, maybe?) he decided he didn’t care for birds and concentrates on squirrels up thru rabbits.

          The other two cats disdain all contact with other creatures and expect to be fed specific food at specific times or else.

          >and biggish yards and lots of nesting birds…lots of birds to kill

          But this is it — birds nest, and most of the offspring die. As do the birds themselves as they reach old age. The point of most animals is to feed other animals, the trick for the feed animals is to breed a lot. The predators get in balance, possibly even in your older leafy suburb. Bird predators are, last I saw, on all continents and have been for… forever. So the question is, how many nests per predator works out? I would say in McMansion hell the number is well undershot. In your leafy suburb…hmm. On my place, again the cat isn’t gonna affect anything impressive as his skills are. (And he does eat what he hunts! – well, usually just the brains but it isn’t just brutality and I think he thinks I need to eat the rest).

          This whole thing is starting to sound like the “individual responsibility” finger pointing. Stop sprawl and a lot of the birds will come back. De-pesticide the farms I expect many more will survive. It’s that simple, and at the same time that hard.

          Somebody in big Ag is really enjoying this. You and him fight!! Sigh.

  13. turtle

    I realize that some people (including some close family members of mine) find it painful to see their cats not be able to go outside. But there’s at least something that can be done to help give the birds a chance if you feel the cat really needs to go outside: collars with bells. It’s only a few dollars to help prevent the death of countless birds.

    Also, don’t worry about choking risks – pet stores sell bell collars with elastic sections that expand to let the cat out from them if they get stuck. You may need to get replacement collars fairly frequently.

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