About two years before the doors to the Denver Zoo’s Bird World were shuttered for good, a former keeper took me for a tour. John Turner worked with Bird World for 22 years—half of the building’s life. When the exhibit opened in 1975, it was state-of-the-art, boasting five heating and cooling systems and natural habitats. But even before Turner retired, over 10 years ago, the facility was failing. He remembers stashing a collection of tools (wire, string, thread, electrical tape, etc.) to fix odd things around the building.

Before heading inside, we stopped by the cassowary in an outer exhibit. As we approached, Turner yelled, “Hey, Dummy!” His exclamation was met with the large, flightless bird sprinting toward us, sheen black feathers rustling with her. Her blue featherless head and neck was adorned with a large horn-looking casque. Her piercing amber eyes drew attention away from her sharp claws. She looked like she could have been a relative to the dinosaurs. But it’s hard to picture her as “the world’s deadliest bird” by the way she curiously followed Turner back and forth.

“You may think she loves me,” he says, “but really, she just wants to eat me.”

The quirkiness of the resident birds is one reason some visitors fell in love with Bird World, but many people missed the charm. “It’s not the most visited part of the zoo,” says CEO Bert Vescolani. “It’s actually one of the least visited areas of the zoo, but for the people who visit it, they love it.”

According to a study published in Science Magazine this year, there are about three billion fewer birds in the Western hemisphere today than there were when Bird World opened. A 2018 global study published by Bird Life International estimates that one in eight bird species worldwide are threatened. With these major declines peppering headlines, it’s hard to imagine why Colorado’s champion of conservation would close Bird World, as they did on October 1—due both the degrading facilities and the exhibit’s popularity.

However, many of the zoo’s efforts to help birds are behind-the-scenes. For example, their avian propagation building, not open to the public and tucked in a far off corner of the zoo, has been operating since 2006. “We were one of the early adopters of creating a breeding center for sustainable populations of all kinds of different species of birds that we have,” says Brian Aucone, senior vice president of animal sciences. Some of the birds in the propagation building are viewable to the public, but many are not.

A Denver Zoo staffer checked in on a Kea chick in the Avian Propagation Center. Courtesy of the Denver Zoo

“What we learn from propagation translates to wild studies,” says Aucone. In their controlled environment, they are able to learn about the variables that lead to successful breeding for a specific species, such as preferred nesting material, temperature, or time of day. That research may translate into understanding changes in wild reproductive rates in certain species (such as climate change, habitat loss, or man-made light or noise disturbances).

The zoo also has their hands in many field projects that will continue to support wild bird populations. For over 20 years they have supported cinereous vultures in Mongolia and work with five species of vultures in Botswana. The vultures they have on exhibit in Denver helped test tracking devices used in the field.

A major restoration project in the Rio Mora Wildlife Refuge in New Mexico has benefited many bird species, including the endangered Southwestern willow flycatcher. They’ve also conducted rescue programs for penguins and flamingoes. “The work in the wild definitely influences us and how we care, what we do, and the decisions we make,” says Vescolani.

The penguin exhibit will move to Predator Ridge in Spring 2020. Courtesy of the Denver Zoo

Decisions are still being made regarding where each Bird World resident will find their new home. Aucone estimates that 70 percent of the zoo birds will remain in Denver. Some, like the keas—a species of parrot native to New Zealand—will move to avian propagation. “We’ve been one of the few zoos successful in breeding them, so we don’t want to give up on that,” he says. Some will head to other facilities accredited by the Association of Zoos and Aquariums. Others will remain in the public eye with new exhibits, like the sloths, which will move to Tropical Discovery. Penguin lovers will be able to see the African penguins in their new habitat in Predator Ridge in the spring, taking the place of the banded mongoose near the zoo’s entrance.

As for the square footage that will be empty after Bird World is demolished—the inhabitants of that new exhibit are yet to be determined. Vescolani ensures that whatever it is, it will be an immersive experience for guests. In the meantime, they hope to continue building partnerships to extend field research and develop programs to educate guests on helping local birds (like creating safe urban habitats, keeping pets indoors, and preventing window strikes).

Bird World in its prime was like stepping into a tropical rainforest—high humidity, trees, tropical birds of every color flying overhead, with a narrow stone path to guide the way. Occasionally you’d hear the echoing call of a hornbill or the trill squawk of an Inca tern. But there are even better things on the horizon for these zoo residents.