Bird Flu Spreads to U.S. Zoos, Raising Concerns for Endangered Species

A surge in avian influenza (bird flu) cases is impacting zoos across the United States, leading to temporary closures and the deaths of several animals, including tigers, lions, cheetahs, and birds. The outbreaks are raising concerns among researchers about the potential “grave implications” for endangered species.

Recent Zoo Closures and Animal Deaths

Several zoos have taken precautionary measures in response to the outbreak. In December 2024, Wildlife World Zoo in Arizona reported the deaths of five animals after testing positive for bird flu . The animals included a cheetah, mountain lion, Indian goose, and kookaburra. San Francisco Zoo temporarily closed its aviaries after a wild red-shouldered hawk found on the grounds tested positive for the highly pathogenic avian influenza (HPAIV) . Woodland Park Zoo in Seattle closed aviaries and suspended penguin feeding in November following the death of a rare red-breasted goose .

Similar outbreaks have occurred internationally. In 2022, Berlin’s Zoological Gardens was closed for a month after the discovery of a bird infected with the H5N1 virus . Over the summer, 47 tigers, three lions, and a panther died in zoos across south Vietnam .

Increased Biosecurity Measures

Zoos are responding to the threat by increasing biosecurity protocols. Sedgwick County Zoo in Kansas is increasing its biosecurity protocols although awaiting test results for a wild bird found on zoo grounds that may have avian flu . The zoo has sent out samples for testing .

The Risk to Captive and Wild Populations

Scientists are concerned that wild birds landing in zoo enclosures could be spreading the virus among captive animals. This poses a significant risk to endangered species, as zoos play a crucial role in conservation efforts. The spread of bird flu through zoos highlights the vulnerability of both captive and wild bird populations to this highly contagious virus.