A new report in the journal Science indicates that the number of birds in North America has declined by several billion in the past 40 years. The findings, released Thursday, suggest that bird numbers are declining more rapidly than previously thought. And researchers are pointing a finger at habitat loss and climate change.
Over the decades, the call of the wood thrush has meant the arrival of spring to the woods of Maine. It's just one of the species of birds experiencing sharp declines. According to a new study published in the journal Science there are 3 billion fewer birds in North America now than in the 1970s. That's a loss of about 25 percent across most species.
"It's kind of a gut-punch for those of us who love birds," says Jeff Wells, the vice president of Boreal Conservation for the National Audubon Society.
Wells is based in Maine and says so many birds that we take for granted here — such as the white throated sparrow, various warblers, and redstarts — are losing numbers.
"Some of the other great thrush songsters, like veeries and hermit thrushes in Maine, you sort of hear them in early mornings or evenings echoing across the landscape, all of those species are among those in this 3 billion bird decline," says Wells.
The research paints a more dire picture than a similar study conducted in 2016 by the Canadian conservation group Partners in Flight, which estimated a loss of more than one-billion birds over the past 40 years. The methodology of the new study, says Wells, included observations of migration density on weather radar, as well as more traditional counting methods.
For those who not only study birds, but also making a living through them, the news is extremely unwelcomed, but unsurprising. Derek Lovitchis a bird guide and owner of Freeport Wild Bird Supply.
"I remember growing up as a birder, the old guard reminiscing about how it used to be, and 'there used to be so many more birds,' or 'we'd come here on this weekend ,and there would always be so many more of this and that.’ Well I sound like those people now," he says.
And Lovitch says there are also birds that have moved into Maine from elsewhere, perhaps being pushed out of their traditional range, responding to a changing climate, or following an invasive insect pest. Lovitch says just fifteen years ago, seeing a red bellied woodpecker or a Carolina wren was a big deal. Today, they're common for roughly half the state.
Meanwhile, other species are all but gone.
"The Rusty Blackbird is a bird that's declined by over 90 percent,” Lovitch says. “I was so excited this summer. I saw my first breeding pair in Maine in probably ten years. That bird has been disappearing, and we're not quite sure why."
Researchers say the reasons behind these bird declines are complex, and include loss of breeding habitat in Maine, habitat fragmentation and disruption, loss of winter habitat, and climate change. Additionally, this month, a study conducted at the University of Saskatchewan suggests that songbirds are being harmed by certain neonicotinoid pesticides — substances also thought to be a culprit in declines of honey bees and other pollinators.
Jeff Wells with the National Audubon Society says the new study shows that North American birds are serving as a large-scale 'canary in the coal mine,' and that it's now clear that the 'canaries' are dying. But he says there are also examples that offer hope, such as the resurgence of wild turkey in Maine after it had completely disappeared after the 19th century.
"We brought bald eagles back by changing laws and policies and bringing resources to the table,” Wells says. “That's the good news. We all have the power to do something."
This story is part of a week-long reporting project Covering Climate Now by Maine Public and more than 300 other news outlets around the world. The series comes in advance of the United Nations Climate Action Summit on Monday Sept. 23 in New York. More information here.