The Brookfield Zoo's new dolphin calf, born less than a week ago, died suddenly Thursday morning, officials said.
"This was devastating to everyone in our zoo family, but particularly to the dolphin staff," said zoo spokesman Bill Zeigler. "Our primary concern now is for the well-being of Allie, who is being monitored closely."
The female, born last Friday and still not named, was announced to the public earlier this week.
Officials said the calf's health suddenly and rapidly declined. A necropsy will be performed to determine the cause of death.
Studies from the Society’s 43-year-old wild dolphin research program in Sarasota, Florida, show that mortalities of neonatal calves during the first 30 days of life account for the largest rate of loss to dolphin populations in the wild, zoo officials said in a news release.