Willow, the 16-year-old reticulated giraffe who was born at the Birmingham Zoo in 2008, has died.

Zoo officials announced Willow’s death Saturday, saying she had not been doing well for several days and her appetite had continued to decline.

A Thursday night exam on the giraffe went well, said President and CEO Chris Pfefferkorn in a letter to zoo members, and Willow was given additional fluids and antibiotics.

“However, we were unable to determine conclusively the cause of Willow’s decline,” Pfefferkorn said.

Willow died early Friday.

“After the exam she did not get back up and quietly passed away despite the heroic efforts of our Zoo team,’’ he said. “We do not yet know specifically what was wrong, but have performed a necropsy and sent tissues out for evaluation.”

Born July 28, 2008, the female giraffe received her name — meaning slender and graceful — from more than 400 submissions. The name was suggested by then-8-year-old Brayden Jones of Adger.

Willow was 6-feet tall and weighed 140 pounds at birth.

“I want to offer my heartfelt thanks to our zoo team for the loving care they have shown Willow throughout her entire life at the Birmingham Zoo and, especially, in her final hours,’’ Pfefferkorn said. “I ask that everyone keep the animal care and animal health teams in your thoughts.”

With Willow’s passing, the Birmingham Zoo has a herd of four reticulated giraffes: Jalil, an 18-year-old male, Juri, a 14-year-old female, Ruby, a 5-year-old female and Mopane, an 8-month-old female.