Inside the Aviary Where Staff Care for Migratory Songbirds — Without Migration

When you step inside the Bird House’s tropical coffee farm aviary at the Smithsonian’s National Zoo in springtime, the first thing you’ll notice is the greenery. After a few moments, the scene comes to life.

Warblers and thrushes sing loudly from the treetops. Bright hues of red and yellow flicker as birds dart through the understory. And overhead, orioles and waxwings perform graceful courtship flights through the air. 

“It’s almost like sensory overload,” said keeper Shelby Burns. “But if you like birds, you’ll never get bored.”

Each spring, millions of birds move north along the Atlantic Flyway on their annual migrations. Inside the Zoo’s coffee farm aviary, Burns and her colleagues care for nearly three dozen migratory bird species that live there year-round. Their work raises a curious question: how do zookeepers take care of migratory birds when they don’t migrate?

Designing a Habitat With Birds in Mind

At the Smithsonian’s National Zoo, animal care often starts with the environment. The Bird House exhibit reopened in 2023 after a major renovation transformed dozens of smaller aviaries into three large free-flight habitats. The “Bird-Friendly Coffee Farm,” the largest of the three, is designed to replicate a lush Central American agroforest, where birds and coffee plants thrive beneath a canopy of tall shade trees. 

In the wild, habitats like these are critical for many of the migratory songbird species that spend spring and summer in the United States and Canada. But over the past century, large swaths of tropical forest ecosystems have been cleared and converted into single-crop plantations, with devastating effects for the ecosystem and the birds that depend on them. The Smithsonian works to support birds in these environments by encouraging farmers to grow coffee and cacao plants under a canopy of native trees, a “Bird-Friendly” solution that benefits both wildlife and farmers. 

Inside the Bird House, the coffee farm aviary recreates the habitat conditions found in both the birds’ tropical wintering grounds and the temperate climates where they mate and raise their young. Layers of tall trees provide opportunities for perching and nesting. Tangles of vines and dense shrubs offer pockets of shelter, while coffee plants fill out the understory. Dappled sunlight, running water, and a misting system create a stable, humid environment. The result is a complex and balanced forest landscape that replicates the ideal conditions for migratory songbirds at any time of year.

In the wild, healthy ecosystems are usually shared by dozens of bird species, and the coffee farm aviary is no different. And with more than 100 individual birds living in the same space, ensuring everything runs smoothly is no simple task. 

A team of ten animal care professionals oversees the welfare of the Bird House’s residents, with Burns serving as the primary keeper of the coffee farm aviary. 

Burns’ day usually starts with a full count and a visual welfare check of every single bird. In a space filled with dense vegetation and constant movement, spotting them all is a unique challenge — even with the help of small ID bands placed on the birds’ legs.

“It’s kind of like a game of hide and seek,” said Burns.

Next is mealtime. A team of commissary staff, keepers, and volunteers prepare trays of fruits, vegetables, live insects and fortified pellets in the kitchens below the exhibit space. Burns refills the feeding stations — and tosses the bugs — around six times a day, with extra servings in the summer when parents are busy feeding their young. 

The menu can shift widely depending on the time of year. For example, an ovenbird will eagerly snatch up insects in the summer, but in winter, the same bird will be far more interested in fruits and pellets.

At the same time, keepers must be careful not to overfeed birds, either. Migratory birds gain weight during key points in the year to build up the fat reserves needed to power long-distance flights. The Zoo’s birds are still attuned to these natural rhythms, so keepers need to balance out calories in spring and fall to ensure the birds maintain a healthy body condition.

Burns also keeps a constant watch on the birds’ cohabitating behavior and social dynamics, relying on a playbook of management solutions when an individual gets too pushy with its neighbors.  For example, if a bird gets too feisty over a coveted nesting site, Burns might hang “distraction nests” in the same tree to reduce competition.

One of the most challenging parts of Burns’ day is when a bird needs a medical exam or must be moved to another enclosure. In a large, free-flight aviary, catching them can take hours, she said. The easiest method is to lure the birds into off-exhibit holding stalls by strategically baiting them with foods the birds enjoy. 

But the birds don’t always cooperate. In one case, a hunt for a wood thrush lasted more than a week — and ended with a stroke of luck. 

“One of the keepers caught it in her hat,” she said.

The coffee farm habitat is designed to support birds through every stage of their life cycle, from courtship and nesting to raising young. Just like in the wild, dozens of chicks hatch in the aviary each spring, an outcome that reflects a deep understanding of the birds’ needs during breeding season.

As breeding season gets underway, keepers help the birds build their own nests. Burns and the team scatter natural materials like dried moss, raffia, cotton, shredded newspaper and even alpaca hair throughout the aviary for the birds to find. Most birds know how to gather materials and build nests intuitively, but the team will step in if a bird looks like it could use some help — or if it’s having trouble with a neighbor. 

“We do have some pairs that try to steal materials from the other birds to build their own nests,” Burns said. “Those are the ones we keep the closest eye on.”

Sunlight is one of the key biological cues birds rely on to determine when it’s time to pair off and find mates. The Bird House is fitted with astrological timers to mimic the day length that migratory birds are accustomed to. For natural light, the aviary’s sunroof is enclosed with a roofing material called ETFE that allows a wider spectrum of sunlight to filter into the space, benefitting both the birds and plants that live in the habitat. 

In the wild, flight is essential to migratory birds’ survival. Juvenile songbirds typically learn to fly and leave the nest during the fledgling stage, normally around 2-3 weeks after hatching.

For the keepers, a chick’s first flight in the aviary is cause for celebration... and a little anxiety. Burns relies on in-depth knowledge of each species to estimate the times between hatching and the development of flight wings.

But chicks don’t always follow the keepers’ preferred timeline.

Indigo buntings, for example, have earned a reputation as being “little daredevils,” rattling their caretakers by attempting to fly before their feathers are fully developed. In cases like these, keepers place soft floor pads where chicks are more likely to flop out of a high nest. Or, keepers may temporarily pull a fledgling off exhibit until it can safely navigate its surroundings.

“It’s always unpredictable, but it’s our job to anticipate it as best as we can,” Burns said.

All that hard work results in a standout experience, both for the visitors and the birds. The space has proved to be an ideal place for visitors to learn about the lifecycles of songbirds in the Western Hemisphere, many of which have declining populations. 

It’s also a place where budding birdwatchers can feed their passion for common backyard birds, said Burns. Since so many species in the coffee farm pass through the Washington D.C., region each year, the coffee farm aviary is a great place for a bird enthusiast to practice identifying local birds by sight and by song. 

For Burns and the keeper team, maintaining an environment ideal for migratory songbirds to thrive requires constant attention, expert care and the ability to get a little creative. But the reward is evident each spring, when the aviary is filled with color, movement, and the chirps of hungry babies.

“It’s a challenge,” she said. “But it’s worth it.”

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