Over Half of Earth’s Migratory Birds Are Declining. Can We Still Save Them?

Washington: Every year, billions of migratory birds connect the world’s continents, oceans and ecosystems by making epic journeys between foraging habitats and breeding grounds.

A bobolink (Dolichonyx oryzivorus) leaves its North American breeding grounds for the Pampas of South America.

A Newell’s shearwater (Puffinus newelli) spends months floating in the North Pacific before returning to the Hawaiian Islands to breed. A spoon-billed sandpiper (Calidris pygmaea) travels from Arctic Russia to the rapidly disappearing tidal mudflats of Southeast Asia for its non-breeding season.

These birds couldn’t be more different. They occupy different habitats, follow different migration routes, and face different threats. Yet they share a remarkable common feature: Their survival depends on habitat networks that span thousands of kilometers and many countries.

Today, all three species and many others are in trouble. Their migrations remain among nature’s most spectacular spectacles, but the birds themselves are increasingly at risk as the habitats and ecological connections on which they depend are lost or disrupted and threats to their ability to survive and reproduce increase.

We study migratory birds as scientists. Together with an international group of colleagues, we recently published a comprehensive assessment of the status, threats, and conservation efforts of more than 3,380 species of migratory birds on Earth.

The results are sobering. We found that more than half of the world’s migratory bird species are in decline due to a range of threats, including habitat loss, invasive species harming birds, collisions with buildings, hunting, the pet trade, toxic pesticides and, in some cases, entrapment in commercial fishing nets.

However, our study offers a second, more promising result. The science on migratory birds has changed dramatically over the past two decades, and if governments take action before they become endangered, conservation can help save these incredible species.

We protect birds on their epic journeys

If migratory bird conservation refocuses on the entirety of birds’ annual cycles, it can protect birds and their habitats year-round, from their breeding grounds to their non-breeding homes and migratory routes in between.

This approach combines protection and restoration of important places, reducing threats wherever they occur. It also relies on international cooperation and proactive conservation led by relevant governments before species become endangered.

Migratory birds are much more than extraordinary travelers. They pollinate plants, disperse seeds, control agricultural pests, transport nutrients between ecosystems, and support local economies by attracting bird watchers and ecotourism.

Their decline is not just a loss of biodiversity; They signal a growing collapse in the ecosystems that sustain both wildlife and humans.

The encouraging news is that humans have never been better equipped to reverse the decline of these species.

Miniature tracking devices, genetics, automated radio telemetry networks, long-term monitoring, and citizen-science initiatives such as eBird that document species numbers worldwide have transformed knowledge about the habits of migratory birds and the risks they face.

For the first time, scientists can track individual birds across continents and determine where conservation actions will have the biggest impact.

A new strategy

For much of the last century, migratory bird conservation has focused on protecting important places such as breeding grounds, wetlands, non-breeding habitats, and migration stopovers on which birds depend.

This strategy has been extremely successful and is still indispensable. Protected areas have prevented countless extinctions and will continue to be a cornerstone of biodiversity conservation.

But research has revealed something equally important: While protecting places is necessary, it’s often not enough to protect species that survive across continents and oceans. It is also important to understand where and when populations are most at risk and address these constraints throughout the birds’ entire annual cycle.

The three species that started this story explain why.

Bobolinks breed in North American grasslands but spend most of the year in South America. Protecting breeding habitat alone cannot reverse breeding declines if grasslands continue to be lost or birds are poisoned by pesticides.

Newell’s shearwaters spend most of their lives in the Pacific Ocean but return to Hawaii to breed; here artificial lights, collisions with power lines, and predators such as domestic cats threaten already vulnerable populations.

Critically endangered spoon-billed sandpipers depend on a network of dwindling tidal mudflats that serve as stopovers between their breeding grounds on Russia’s Chukotka Peninsula and their non-breeding grounds in Southeast Asia.

Losing even a handful of these stopover sites could endanger one of the world’s rarest migratory birds.

Each species requires a different conservation strategy, but they all require the same way of thinking: protecting their entire annual cycle rather than focusing on a single location, season or threat.

Fortunately, this approach is already taking hold in the United States and showing what is possible.

What might success look like?

Path to Recovery is an international initiative designed to reverse losses of North America’s fastest-declining bird species before they need protection under U.S. endangered species legislation.

Rather than waiting for populations to disappear, Road to Recovery brings together scientists, governments, conservation organizations, landowners and local communities to form species working groups. These groups help determine the harms facing bird populations and how to act more surgically when limited conservation money is available.

Today, more than 50 international working groups are developing conservation strategies for species from bobolinks to lesser yellow-legged (Tringa flavipes) to evening roughbills (Coccothraustes vespertinus) and yellow-billed cuckoos (Coccyzus americanus).

Their work has already led to new research, habitat conservation, policy changes, hunting reforms and international partnerships.

International agreements such as the Convention on the Conservation of Migratory Species of Wild Animals, as well as regional flyway partnerships and agreements, provide ways for countries to work together to protect migratory species across political borders.

However, the fact that many of the world’s largest, richest and most influential countries have not signed the agreement seriously hampers its effectiveness. This includes the United States, Canada, Mexico, Russia and Japan.

Broader international involvement and sustainable investment by governments can help translate scientific knowledge into coordinated conservation action across the entire annual cycle.

But governments cannot do this alone. Landowners, businesses, conservation organizations and individuals all have roles to play. They can help protect and restore habitats and reduce threats such as free-roaming cats and collisions with buildings. They can support bird-friendly policies and participate in citizen science programs that help monitor migratory bird populations.

Applying these lessons

There is every reason to hope.

Conservation initiatives around the world repeatedly show that bird populations recover when threats are identified and addressed. The pesticide DDT caused the near extinction of species such as the bald eagle, peregrine falcon, and osprey, but humans stepped in, banned its use, and all species were saved.

The challenge now is to apply what science has found.

Next spring, bobolinks will once again return to the grasslands of North America. Newell’s minute hands will return to Hawaii across thousands of miles of open ocean. Spoon-billed sandpipers will once again attempt one of the world’s most extraordinary migrations.

Whether future generations will continue to see these spectacular migrations will depend on the choices of current generations and the steps they take to save them. (Chat)