The Reid Park Zoo announced the deaths of two animals on Monday.
Moms, a 47-year-old white-handed gibbon, was humanely euthanized on July 8 from "age-related health issues," according to an online news release.
"Euthanasia is always a difficult decision to make and we take into account many factors. Ultimately, we made this decision with heavy hearts based on her declining quality of life. It became clear, we could no longer overcome the issues that developed with her advanced age,” said Dr. Alexis Moreno, a veterinarian at the zoo, in a prepared statement included in the release.
The average lifespan for white-handed gibbons is 25 to 30 years, the zoo said.
Lucy, a four-year-old ostrich, died on July 6 "due to complications associated with an obstruction in her gastrointestinal (GI) tract," according to the release.
With the death of Moms, the zoo now has one gibbon, Billy, who is 43. The Tucson zoo said he is healthy and eating well.