The Omaha Henry Doorly Zoo and Aquarium closed several exhibits on Saturday after a pink-backed pelican passed away due to highly pathogenic avian influenza.
In a statement, the Nebraska zoo said the Simmons Aviary, Lied Jungle and Desert Dome would be closed for at least 10 days.
The pelican died on Oct. 13 and was tested as part of the zoo's continued surveillance for bird flu – which has impacted bird populations around the world this year.
The zoo said that a second pelican had become sick on Friday and was euthanized.
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The pelicans currently live outside and, although they can come into contact with wild waterfowl, they have no contact with other zoo birds.
The zoo said the waterfowl carry the virus – often without becoming sick – and that detections of HPAI have increased nationwide due to fall migration patterns.
No other birds at the zoo have shown any symptoms or required testing.
HPAI is mainly transmitted from the feces of wild birds and the zoo has a prevention and response plan in place.
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Zoos across the country closed down aviaries and moved birds inside earlier this year and the outbreak has started to make a resurgence.
Over 47 million chickens and turkeys have been slaughtered across 42 states.
On Sunday, Knuckle Bump Farms' Taylor Blake announced that viral sensation Emmanuel the emu had been sickened and that the farm had been hit hard by avian influenza, losing 99% of the birds on the farm.
Earlier this month, penguins at Cape Town's Boulders beach were reported to have died from avian flu and the BBC reported last week that the U.K.-based Broads Society is demanding help from the government after the worst-ever avian flu outbreak in the region.
Millions of birds have been culled, although the U.K. Health Security Agency – and others – have advised that the risk to human health is very low.
Reuters and The Associated Press contributed to this report.