Why are zoo keepers called animal "trainers" when they're not "training" anything?

Per this story what exactly is she training the tiger to do?

They do train the elephants. They have to, to do things like lift their feet for cleaning and such. At least at the local zoo, that’s the only “trained” animal.

They do a lot of training. It’s slower, and not as dramatic as with domestic animals, but they do train them. The training is usually centered around making it easier for a vet to examen the animal if it gets sick. A really common training for hoofed stock, for example, is to hande their feet. Makes it easier to keep their hooves trimmed. Very important for animals that aren’t walking the miles they normally would be and therefore aren’t wearing down their hooves and feet pads properly. Prevents lots of problems if you can train them to allow their feet to be handled and trimmed without sedating them.

Damn! Zsofia beat me to it.
Another example: training monkeys (lesser ape types) to come to a target so that they can be examened visually up close. If you just left them in the enclosure without training, they would be to scared.

make that “too.” Goddamn rapid clicking!