WCS has been involved in bird conservation for more than 100 years, initially driven by the Bronx Zoo’s ornithology curators. Our scientists, conservationists, zookeepers, curators, veterinarians and policymakers all have played historical roles in efforts behind the conservation of hundreds of bird species and their habitats. Dr. Anna Lello-Smith is our newest ornithologist who joined WCS in 2023 as the avian conservation coordinator for the WCS Mesoamerica & Western Caribbean Program. She recently completed her PhD at the Cornell Lab of Ornithology. For World Migratory Bird Day, which is May 13, we asked Dr. Lello-Smith to help us understand the importance of migratory birds.

WCS's Dr. Anna Lello-Smith: It might seem like migratory birds only matter to the crazy birders (like me) who love watching them through binoculars. But in reality we all depend on birds and the “ecosystem services” they provide to us, often in ways we don’t see.

Birds help produce the food we eat by pollinating important agricultural crops and consuming the insects that damage them. Birds that eat fruit, like parrots and orioles, help forests grow (and grow back after deforestation) by dispersing seeds across the landscape. Birds that eat carrion, like vultures, play a key role in reducing the spread of disease. Birds also move nutrients between habitats and across landscapes, which supports healthy nutrient cycling and ecosystem functioning. This is especially true for migratory birds that travel across vast distances, eating in one place and excreting in another place miles away.

By playing all these diverse roles, birds underpin healthy ecosystems, which in turn provide the clean air, clean water, healthy soil, and regulated climate that we all depend on to survive. Last but not least, migratory birds and their incredible journeys – like the Hudsonian Godwit that travels almost 10,000 miles from Arctic Alaska to the tip of South America and back each year – give us a sense of wonder and remind us that we are all connected to each other across vast distances and national boundaries.

WCS's Dr. Anna Lello-Smith

Dr. Lello-Smith: Migratory birds are experiencing staggering losses in abundance. North America alone has lost 3 billion birds since 1970, and this includes many migratory species that are in steep decline. But this isn’t just an Americas problem—almost half of all bird species worldwide are undergoing population declines. We do and we don’t understand why this is happening.

Broadly, we know that climate change, rampant destruction of important bird habitats, pesticide use, outdoor cats, window collisions, and the pet trade are contributing to these widespread declines. But many bird species have vast ranges and are exposed to multiple threats throughout the year, and for most species we still don’t know which threats are most responsible, or where and how they are harming birds most.

Answers to these questions are critical for recovering species before it is too late. For example, researchers have discovered that the biggest threat to the endangered Saltmarsh Sparrow is sea level rise, which is causing high rates of nest failure for this coastal marsh-nesting bird. Identifying this cause and understanding how it is driving the decline of this sparrow enables managers to implement targeted actions like restoring marsh habitat on higher ground. We need to identify specific causes of decline for a lot more species, while simultaneously addressing broad threats like habitat loss on the breeding and non-breeding grounds that we know are impacting many species."

The wood thrush is an iconic, declining migratory forest bird

Dr. Lello-Smith: It’s easy to feel helpless in the face of so much disastrous environmental news. But actually, there are a surprising number of concrete actions that individuals can take to help protect migratory birds.

A big one is keeping your house cats indoors. Outdoor cats kill an estimated 1.3–4 billion birds every year in the U.S. alone. Instead of letting your cats roam free outside, try walking them on a leash or building a “catio” so they can enjoy the outdoors without threatening birds and other local wildlife.

Window collisions are also a huge source of mortality for birds, especially during spring and fall migration. If you own a building or have large glass windows, consider adding bird-safe window treatments and turning out your lights (which can confuse migrating birds and cause them to crash into buildings) during peak migration nights.

Two other actions that individuals can take are to (1) plant native plants in your yard and, if you’re a coffee drinker, (2) drink certified Bird Friendly or other shade-grown coffee. Native garden plants are better for birds than grass lawns! And shade-grown coffee, which is grown on farms with enough tree cover to provide habitat for dozens of migratory bird species, is better for birds than sun-grown coffee, which is grown on deforested farms that are inhospitable to most birds.

Beyond individual lifestyle choices, you can support on-the-ground efforts by WCS and other conservation organizations to work with local partners to protect and restore critical habitats throughout the ranges of migratory birds. We also need legislation and large-scale systemic change to reverse the global crisis that birds are facing; but we can each do our part to help save the birds we love and depend on.