Courtesy National Zoo

The Smithsonian’s National Zoo on Friday announced the recent deaths of two scimitar-horned oryx. One female died at the main Zoo campus on Oct. 24, while a male passed away on Oct. 14 at the Conservation and Research Center in Front Royal.

The female died after having had to be anesthetized twice in two days, first for a regular check-up and then again after she became agitated during recovery and appeared to have injured her hind legs. The zoo said preliminary necropsy results suggest the oryx died of “exertional myopathy,” which can be related to over-exertion and/or hyper-excitability. The male oryx died after going into cardiac and respiratory arrest while being anesthetized for a routine reproductive assessment.

Scimitar-horned oryx, which were native to north Africa, are now extinct in the wild. The zoo now has one oryx remaining on exhibit and 13 in Front Royal.