The Smithsonian’s National Zoo and Conservation Biology Institute is mourning the loss of a 2-year-old female addax named Terri who died June 12. While Terri was moving and behaving normally earlier in the day, just before noon Africa Trail keepers found Terri deceased near a fence that separates the addax and ostrich habitats. Although keepers did not witness the events leading up to her death, necropsy reports showed evidence of a cervical fracture, which indicates that something may have spooked Terri and caused her to run and collide with the fence.

Terri and her two herd mates—a male named Jack and a female named Janet—arrived at the Zoo in November 2021. They serve as ambassadors of their species, which are considered critically endangered in the wild. Native to Chad and Niger, addax face threats including drought, hunting and habitat loss from oil drilling and agricultural expansion. The life span of the addax is unknown in the wild. In human care, individual males have lived up to 11 years and individual females have lived up to 14 years.