Tundra swans, which nest in the Arctic and migrate south in fall, alight at Mattamuskeet National Wildlife Refuge in North Carolina
Allie Stewart/USFWS, CC BY
T
he Trump administration has announced a position on protecting migratory
birds
that is a drastic pullback from policies in force for the past 100 years.
In 1916, amid the chaos of World War I, U.S. President Woodrow Wilson and King George V of Great Britain signed the
Migratory Bird Treaty
.
The Migratory Bird Treaty Act (MBTA)
wrote the treaty into U.S. law two years later. These measures protected
more than 1,100 migratory bird species
by making it illegal to pursue, hunt, take, capture, kill or sell live or dead birds, feathers, eggs, and nests, except as allowed by permit or regulated hunting.
This bold move was prompted by the decimation of bird populations across North America. Some 5 million birds, especially waterbirds like egrets and herons, were dying yearly to provide
feathers to adorn hats
, and the passenger pigeon
had just gone extinct
. Fearing that other species would meet the same fate, national leaders took action.
Snowy egrets were hunted close to extinction in the late 1800s to supply plumes for hats.
Now the Interior Department has issued a
legal opinion
that reinterprets the act and excludes “incidental take”—activities that are not intended to harm birds, but do so directly in ways that could have been foreseen, such as filling in wetlands where migrating birds rest and feed. Why? For fear of “unlimited potential for criminal prosecution.” As the argument goes,
cat owners whose pets attack migratory birds
or drivers who accidentally strike birds with their cars might be charged with crimes.
But the MBTA has not been enforced this way. It is applied to cases of gross negligence where potential harm should have been anticipated and avoided, such as
discharging water contaminated with toxic pesticides
into a pond used by migratory birds. This new reading of the law means that companies will escape legal responsibility and liability for actions that kill millions of birds every year.
Pollution, development and habitat loss kill birds
Purposeful killing is only one of many threats to migratory birds. Habitat loss, invasive species, pollution, and
collisions with buildings
take heavy tolls on many species. According to the U.S. Fish and Wildlife Service, every year
more than 40 million birds are killed
by industrial activities or structures such as power lines, oil pits, communication towers, and wind turbines. The 2010
Deepwater Horizon oil spill
in the Gulf of Mexico killed more than 1 million birds in a single event.
Seventeen former Interior Department officials representing every presidential administration from Nixon through Obama have written a
memo
expressing deep concern about the new policy. As they explain, the MBTA has given industries a strong and effective incentive to work with government agencies to anticipate, avoid and mitigate foreseeable death or injury to birds.
For example, it prompted energy companies to install nets above pits where they store waste fluids from oil drilling. Because these pits look like
water
sources, birds often land on them and can become trapped and die. Installing nets over the pits has
cut annual bird deaths
from roughly two million birds yearly to between 500,000 and one million. Not perfect, but a meaningful improvement.
Global citizens, global consequences
Because migratory birds don’t recognize international boundaries, the consequences of reinterpreting the MBTA may be felt across borders. In one year, an individual warbler may spend 80 days in Canada’s boreal forests, 30 days in the United States at resting and refueling sites during migration, and over 200 days in Central America.
At the
Cornell Lab of Ornithology
, we have constructed maps and
animations
using data collected by volunteers for
eBird
, the world’s fastest-growing biodiversity database. These references illustrate how migratory birds connect countries. Many spend the year in locations that span the Western Hemisphere.
Migration pathways for populations of 118 migratory birds species within the Western Hemisphere from 2002 to 2014, based on data from eBird.
La Sorte et al., 2016, http://dx.doi.org/10.1098/rspb.2015.2588., Author provided
The eastern-breeding
magnolia warbler
, for example, spends winters in areas in the Yucatan Peninsula and Central America that are fractions of the size of its breeding range. Seeing how densely these birds are clustered in their winter habitat shows us that each acre of that territory is important to their survival.
Breeding, migration and winter abundance of the magnolia warbler based on computer models using eBird data.
State of North American Bird report
Similarly, most populations of the western-breeding
western tanager
overwinter in Mexico. By identifying where bird populations winter in this way, we can better target conservation actions to protect species throughout their annual cycles.
Year-round abundance map for the Western tanager based on computer models using eBird data.
State of North American Birds Report
Conserving migratory birds requires effective protection both in the United States and through international agreements and partnerships. The most important threats are loss and degradation of habitat, which can be caused by land conversion—for example, clearing forests for farming—or by
climate change
.
In the 2016
State of North American Birds
report, an international team of scientists assessed the conservation status of 1,154 birds across Canada, the United States and Mexico. They found that over one-third of all North American bird species are at risk of extinction without meaningful conservation action.
Birds associated with oceans and tropical and subtropical forests year-round are in the most dire straits. More than half of North American seabirds are declining due to pollution, unsustainable fishing, energy extraction, pressure from invasive species, and climate change. Birds that rely on coasts, arid lands, and grasslands also are in serious decline.
A dead albatross on Midway Atoll in the North Pacific with plastic waste in its stomach.
Chris Jordan, U.S. Fish and Wildlife Service/Flickr, CC BY
There are no easy solutions, but new science is supporting responses. Transformational citizen science projects like
eBird
are developing vast data sets to help pinpoint where conservation action should focus. Bird conservation groups and government agencies have formed international teams to
eradicate invasive predators on islands
that are critical to breeding seabirds and drafted multinational agreements to
clean up large floating mats of garbage
in our seas that can choke, trap or poison seabirds and other animals.
Birds are a shared resource among nations. Where governments have acted, they have successfully protected migratory birds and the habitat they depend on. In my view, the Trump administration’s shift would abdicate U.S. leadership on migratory bird conservation and undermine public good for private profit.
Amanda Rodewald is a Professor and Director of Conservation Science, at the Cornell Lab of Ornithology, Cornell University. This article was originally featured on
The Conversation
.
