Breeding behavior is extremely variable and takes many forms. This behavior can include elaborate courtship displays, combat, or even methods such as those used by some salamanders, where the male deposits a spermatophore that the female must pick up with the muscular lips of her cloaca in order for the eggs to be fertilized. This is a method that most of us would probably consider slipshod and unlikely to succeed.

The zookeeper must be aware of the behavioral changes associated with the breeding season. Some male animals, such as elephants, may become very aggressive and extremely dangerous. Female behavior usually changes after impregnation and close to parturition time. Normally approachable animals can react quite differently. Keepers must know when animal births are imminent so that proper precautions can be taken to ensure the best possible chances of safe delivery. In the past, many zoo animals or newborns have died during the birth process so it is important to be prepared for the event by anticipating what might go wrong and developing a mitigation plan. Mating strategies range from a single mated pair to polygamous situations where a female may mate with many males or males may mate with several females. In the peculiar mating strategy of several birds and some mammals, males defend an area among several other male's territories. In this so-called lek the females come and mate with a male that holds one of the small territories. Usually, this is near the center of the group of defended areas.

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