When a curator of the bird collection at Smithsonian’s National Zoo in Washington came to work on Monday morning, she was startled to see a wild fox leaving the flamingo habitat.
By then, it was too late.
The fox had killed 25 American flamingos and one northern pintail duck, apparently after gnawing a softball-size hole in the metal mesh surrounding the birds’ outdoor yard.
“I can’t even imagine the effort,” Brandie Smith, director of the National Zoo and the Smithsonian Conservation Biology Institute, said in an interview, adding that it was most likely the work of “a very determined fox” that may have been trying to provide for its young, known as kits.
Now, the zoo is toughening the security measures around its bird exhibits in case the fox, which escaped, strikes again.
The zoo called it “the first predator mesh breach” at its flamingo exhibit, a 9,750-square-foot expanse with a heated pool and barn, which has remained largely unchanged since the 1970s. Three other flamingos were injured in the attack and were being treated at the zoo’s veterinary hospital.
“This is a heartbreaking loss for us and everyone who cares about our animals,” Dr. Smith said in a statement. “The barrier we used passed inspection and is used by other accredited zoos across the country. Our focus now is on the well-being of the remaining flock and fortifying our habitats.”
Renowned for their bright pink plumage and elegant one-legged stance, flamingos can live for about 40 to 60 years, and the zoo still has 49 in its collection. Though not considered endangered, they are relatively rare in the United States. But they have been known to defy the odds.
In March, an African flamingo known simply as No. 492 was spotted by a fishing guide in Port Lavaca, Texas, 17 years after it flew away from the Sedgwick County Zoo in Wichita, Kan.
Foxes have also been known to prowl Washington. Last month, a fox roaming Capitol Hill bit at least nine people, including a member of Congress, before it was caught, euthanized and tested positive for rabies. The fox’s three kits were also euthanized because of their exposure to their rabid mother.
Officials at the National Zoo said that employees check the perimeters of the bird exhibits twice a day to ensure they are intact, and that nothing was amiss when the outdoor yards surrounding the Bird House were last inspected at 2:30 pm on Sunday.
But after the birds were found mauled on Monday morning, zoo workers noticed a small hole in the mesh enclosure, which was last replaced in 2017 and passed an accreditation inspection by the Association of Zoos and Aquariums.
Dr. Smith said that the zoo was now adding more wire mesh around the flamingo area and other bird enclosures, and installing more electrified fencing to repel foxes and other predators, such as raccoons, that live near the zoo.
Zoo workers, she said, were also setting up live traps to catch wild animals, and digital cameras with infrared motion sensors to monitor the movements of any creatures that might be nosing around the zoo grounds at night.
The surviving flamingos have been moved indoors to their barn and the remaining ducks to a covered, secure outdoor space, zoo officials said. But zoo workers who tended to the flukes were still devastated, Dr. Smith said.
“This is an incredible staff of people who had to respond to the death of the flamingos, and also make sure the rest of the flamingos and every other bird was protected,” she said. “The whole team is still in shock.”