Celebrating and Conserving Migratory Birds

May 8, 2021 is World Migratory Bird Day in the Americas.

As someone whose movements more closely approximate those of a barnacle than a barn swallow, I am mystified by migratory birds. How do such small, delicate-seeming creatures dare to make their journeys?

Migration has never been without risks, and human changes to the environment create new ones. Habitat loss, urbanization, artificial light at night, pesticides, outdoor free-roaming cats, and other human-related disturbances are taking a toll. In North America, nearly 60% of native migratory bird species are already in decline. A future with climate change further threatens this amazing group of birds.

Because they often have huge ranges that cross international borders, conserving migratory birds for future generations requires collective action. In celebration of Migratory Bird Day 2021, let’s take a look at three unique migrants and a few small ways we can help them.

Swainson’s Thrush

Swainson’s Thrush / Mick Thompson

Of all our migratory birds, there is none whose return I anticipate more eagerly than the Swainson’s Thrush. They make their way north to breed in the forests of the Pacific Northwest from wintering grounds in Central and South America. They should just be starting to arrive in Washington now. They aren’t very showy birds—brownish on top and white with dark spots below—but no matter. I hear them more often than I see them, and it is their song that stuns. Listen to the Swainson’s Thrush’s upward-spiraling, flute-like song:

Swainson’s Thrush song / Taylor Brooks / Cougar Mountain, King County, WA

Dope, right? But we’re not even hearing the half of it.

There is evidence that some birds can “hear faster” than humans and may be able to distinguish subtle details in their vocalizations that our “slow” human ears miss. I’ve slowed the the Swainson’s Thrush song to 1/10th its normal speed to help us appreciate the acoustic richness the birds may be vibing to:

Swainson’s Thrush song 0.1x speed / Taylor Brooks / Cougar Mountain, King County, WA

Sadly, the Swainson’s song is growing quieter. Populations have declined by more than 30% since the 1970s (Supplemental Data, Rosenberg et al. 2019). We don’t have a definitive explanation for the downward trend, but collisions with windows, buildings and other structures during migration are a significant cause of mortality. In some parts of the country, more Swainson’s Thrush are killed due to collisions with structures than any other bird species. In the Seattle area, Swainson’s Thrush are the 6th most commonly admitted bird species for collision related injuries at the PAWS wildlife clinic.

You can help the Swainson’s Thrush:

• Urge your U.S. legislators to co-sponsor and support the Bird-safe Buildings Act of 2021.
• Help birds see and avoid your windows.
• Go lights out during migration season.
• Report dead and injured birds at dBird.org.

Rufous Hummingbird

Rufous Hummingbird feeding on Red-flowering Currant / Leslie Scopes Anderson / Great Backyard Bird Count

-Rufous Hummingbirds are small: just a couple of inches long and lighter than a nickel. Despite their small size, rufous hummingbirds make one of the longest migratory journeys relative to body length of any bird in the world. These birds feed on nectar, and their migration route follows the flowers. You can see their elliptical, clockwise migration pattern in the animation below. They move up the coast in late winter and arrive in the Pacific Northwest around the time red-flowering currant reaches peak bloom. They breed here, making nests of moss and spiderwebs, laying jelly bean-sized eggs, and feeding insects to the chicks that eventually hatch. Around mid-July they head back south, this time following a highland route full of summer flowers through the Cascades, Sierra, and Rocky Mountains.

Climate change threatens these amazing little birds. Earlier springs, longer summers, changes in rainfall and other climate impacts affect the timing of blooms, insect emergence, and animal movements. However, not all species are responding to climate change at the same speed or in the same ways, and this can lead to mismatches: Where blooms peak before hummingbirds arrive, for example.

The Rufous Hummingbird is extremely vulnerable to mismatches and other climate impacts. The National Audubon Society projects that nearly three quarters of the Rufous Hummingbird’s summer range will be lost under a three-degree Celsius warming scenario.

Rufous Hummingbirds are projected to lose 71% of their summer range under a three-degree Celsius warming scenario. For more information, visit climate.audubon.org.

In cities, we may be able to improve the climate resiliency for some vulnerable species. Since urban habitats can be planned, managed, and monitored intensely, we can thoughtfully incorporate vegetation in gardens, parks, and the right of way to provide abundant, year-round resources for wildlife. We can also enhance connectivity between existing greenspaces to facilitate movement and access to resources.

That’s the idea behind Seattle Audubon’s Capitol Hill Connections project. Our goal is to connect habitat patches in Capitol Hill in a nearly two-mile long project area extending from Seattle University to Volunteer Park. Over 100 bird species occur within this area, along with unknown hundreds of other plant, animal, and fungi species. We’re working to plan not only for habitat enhancements, but to build community and foster personal connections with neighborhood nature, too. And, what we learn can be applied in other neighborhoods.

You can get involved: 

• Attend an upcoming Nature of Your Neighborhood workshop.
• Garden in the right-of-way to improve habitat.
• Try container gardening with wildlife supporting plants.

Snowy Owl

Snowy Owl / Karen Schiller / Audubon Photography Awards

For many owl species, the best a birder can do is appreciate the disembodied hoots emenating from the forest. Not so with the Snowy Owl. It is one of the easiest to detect. For starters, they are large. In fact, one of the largest owls in the world. They are unmistakable with their striking white faces and intense yellow eyes. They are also active during the day and tend to sit out in the open for extended periods. Those characteristics make them conspicuous creatures on the landscape, unlike some of their secretive, forest-dwelling kin.

While Snowy Owls might be easy to detect, you’re not likely to encounter them frequently in Seattle. They spend summers on the Arctic tundra. In winter they mostly stay within Canada and Alaska. But they will occasionally show up in Seattle and when they do, they make the news.

While in Seattle, Snowy Owls have been observed eating rodents. This would be nothing but good news if it were not for human pest management strategies that poison the owls’ food supply. Some of the most popular commercial rodent control products contain a class of poisons called second generation anticoagulant rodenticides (SGARs). SGARs are highly toxic, slow acting, long lasting, and accumulate not only in the bodies of the rats that eat the poison, but in the bodies of animals that eat the poisoned rats.

SGAR bait station near apartment building, Capitol Hill, Seattle / Joshua Morris

Seattle Audubon is supporting efforts at Cal Anderson Park and the Queen Anne Business District to explore rodent control solutions that pose fewer risks to birds of prey, be they irregular migrants like the Snowy Owl or long-term residents like our Cooper’s Hawks.

You can help:

• Refuse to use SGARs. Learn about alternatives.
• Notice SGAR bait stations around your neighborhood and discuss them with your friends and family. Awareness is growing of the dangers of SGARs, but there’s still a lot of work to do.

Gifts, Not Guarantees

This year the Swainson’s Thrush will sing. The Rufous Hummingbird will follow the flowers. A Snowy Owl may contemplate a winter trip to Seattle. These are gifts. They are not guarantees. This Migratory Bird Day, I’m celebrating with gratitude the birds that add song to the spring and color to the sky, that connect people and places across hemispheres, and that call us to act for a future where both people and birds can thrive.