Brookfield, Ill.— The dolphin care team at Brookfield Zoo is mourning the death of its nearly one-week-old female dolphin calf, which died this morning following a sudden and rapid decline. A necropsy (animal autopsy) is pending.

“This was devastating to everyone in our zoo family, but particularly to the dolphin staff. Our experienced veterinary and marine mammal staff provided the best possible care to the calf’s 26-year-old mother, Allie, throughout her pregnancy,” said Bill Zeigler, senior vice president of collections and animal care for the Chicago Zoological Society. “Our primary concern now is for the well-being of Allie, who is being monitored closely.”

Brookfield Zoo, which is managed by the Society, announced the calf’s birth with a news release Wednesday morning. Until that time, the calf appeared to be doing well, swimming with its mother. The animal care specialists were cautiously optimistic about the calf as they monitored key milestones, including nursing from Allie. However, on late Wednesday and early this morning, they observed that the frequency and duration of nursing began to diminish.

“Young calves can fade extremely quickly, so milestones are tracked around the clock,” said Michael Adkesson, DVM, DACZM, vice president of clinical medicine for the Society. “We became increasingly concerned this morning when we noticed that the calf was showing signs of weakening.”

Veterinarians intervened, providing the calf with supportive care and treatments. Allie, as an experienced mother, was demonstrating all the correct behaviors. However, the calf continued to decline. When it became apparent that the calf was failing, staff stepped in again, providing CPR in an attempt to resuscitate her, but efforts were unsuccessful and the calf passed away.

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.