From salamanders and porcupines to maned wolves and Asian elephants, we care for a wide range of species at the Smithsonian’s National Zoo and Conservation Biology Institute. While we can simply scoop up some animals for checkups, like our friendly three-banded armadillo, other species are more challenging. There are some animals that we never share a physical space with because their size, strength or natural behaviors could be hazardous for keepers and veterinarians.
It is important for animals (including large predators) to express their natural instincts, but staff safety is also key. One way we prioritize both is by working with some species — such as lions, tigers and gorillas — in a protected contact setting. Protected contact means there is always a physical barrier, such as fencing or steel mesh, between an animal and a person, including for training sessions, health checks and routine care. The only exception is if an animal is sedated by the veterinary team for a special exam.
So, how do we give a big cat or a 400-pound gorilla a checkup? We use training and positive reinforcement. During training sessions, we can use hand signals and verbal cues to ask an animal to voluntarily approach a barrier and turn a body part toward us. Many sessions start by asking an animal to move toward a target, such as a red sphere on the end of a stick. This is called target training. When the animal moves to the target, a reward helps to reinforce the good behavior. For lions, a training reward is often a chunk of meat.