The National Audubon Society and other wildlife organizations have declared 2018—the 100th anniversary of the Migratory Bird Treaty Act—to be the Year of the Bird. ©John T. Andrews

Wildlife science has many measurements; for example, “carrying capacity,” “depredations” or “translocations.” But there’s a new scale I recently came across: “bird years lost.”

A bird year is a quantity devised by ornithologist Daniel Cristol at the College of William and Mary in Williamsburg, Virginia. In a research project, he traced mercury in poisoned songbirds back to its industrial source. From that evidence, he was able to formulate a method for holding polluters financially accountable: he could compute the damage in bird years lost.

This new yardstick comes at an opportune time because the National Audubon Society, National Geographic, the Cornell Lab of Ornithology, BirdLife International and others have just announced that they are declaring 2018 to be the Year of the Bird. It’s an appropriate designation since 2018 also marks the centennial of the Migratory Bird Treaty Act (MBTA).

During their biannual migrations, American white pelicans—one of the largest birds in North America—stop on lakes and rivers. ©John T. Andrews

Unfortunately today, a hundred years after its creation, the act is under attack. And earlier this year, a ban on the use of lead ammunition on federal lands was overturned, handing another blow to our birds.

In the past, we exterminated many species of birds through hunting and habitat destruction. With our hard-won protections for birds now being whittled away once again, will Year of the Bird 2018 have any impact on this new movement to eradicate more birds in the future?

Migrating mercury and abating bird years

In the 1970s, the chemical company DuPont released mercury from one of its facilities into Virginia’s South River and the South Fork of the Shenandoah River. In order to determine the value of its liability, DuPont hired ornithologist Daniel Cristol to determine to what degree the company’s pollution affected local birds.

How many bird years have been lost due to human impacts on avian habitats? ©John T. Andrews

What Cristol found was surprising: the DuPont mercury spill had spread much farther into the avian food web than anyone had previously suspected. Not only was the chemical found in fish-eating raptors, such as eagles and ospreys, but it was also present in the blood of birds that lived their lives far away from the contaminated South River. It was in terrestrial and nonriverine bluebirds, Carolina wrens, red-eyed vireos, thrushes and tree swallows.

The next step was to establish just how many birds the mercury had harmed and how badly. This number—and the dollar amount needed to restore bird numbers to their pre-DuPont levels—would determine the price tag of the settlement. It was a matter of calculating the number of bird years lost.

It’s a poetic-sounding measure for paucity.

Act under attack and losing to lead

According to the National Audubon Society, the hope for naming 2018 the Year of the Bird is that the combined storytelling expertise of all of the partner organizations will elevate our estimation of birds and the important place they have in our ecosystems.

Millions of birds are poisoned by lead every year. Bald eagles accidentally ingest lead ammunition fragments when scavenging on the remains of carcasses left by hunters. ©John T. Andrews

One hundred years ago, the staggering destruction of birdlife caused by the plume trade spurred the passage of the Migratory Bird Treaty Act, one of the earliest environmental laws passed anywhere in the world. While fashion trends have changed, the law remains as important as ever. Birds now face 21st-century threats, such as gas flares, oil spills, oil waste pits, transmission lines, wind-power turbines and more. The act has been used to help reduce those impacts and to implement practices that save birds’ lives.

But the Migratory Bird Treaty Act is now endangered. In an October 24, 2017, report from the Department of the Interior, the administration indicated that it is reviewing possible far-reaching changes to its enforcement of the act. It states, among broader attacks on environmental protections, that the department will “re-evaluate whether the MBTA imposes incidental take [unintended bird deaths that result from industrial activity] liability” and consider new guidelines or regulations.

It wasn’t the first time birds were hit with rollbacks in their protections in 2017. Early in the year, Interior Secretary Ryan Zinke signed an order overturning a ban on using lead ammunition on wildlife refuges.

Estimated to be about 10 million years old, sandhill cranes are the oldest known bird species on Earth. But will they survive the 21st century? ©John T. Andrews

More than 500 million of America’s nearly 700 million hunting-approved acres are under some kind of federal jurisdiction. That means that—according to the Center for Biological Diversity—an estimated 20 million wild animals will continue to die each year from lead poisoning. A decades-long effort to get lead shot out of America’s backcountry was annihilated with the stroke of a pen.

We are all birds

In her 2012 book When Women Were Birds: Fifty-Four Variations on Voice, author and environmental activist Terry Tempest Williams wrote, “Once upon a time, when women were birds, there was the simple understanding that to sing at dawn and to sing at dusk was to heal the world through joy. The birds still remember what we have forgotten, that the world is meant to be celebrated.”

So while our birds still sing, I hope we will all join in the celebration of 2018 as the Year of the Bird. But, while we’re doing that, let’s remember that those tuneful voices that lift us in our darkest hours are the ones that we humans are actively working to silence once again, possibly for forever.

Here’s to finding your true places and natural habitats,