The security measure comes a day after poachers killed a four-year-old rhino and removed the animal's horn at Thoiry Zoo, west of the French capital, Paris.
Security is being reviewed at zoos across Europe a day after poachers killed a white rhino in a French wildlife park.
The intruders used a chainsaw to remove the animal's horn during Tuesday's raid, believed to be the first of its kind in the continent.
The four-year-old male, named Vince, was found dead in the African enclosure of Thoiry Zoo, west of the French capital, Paris.
Police said the animal had been shot three times in the head and one of its horns had been sawn off.
The poachers could not remove Vince's second horn and left it partially sawn.
TRT World's Sarah Morice has more details.