Knowing the animal's natural environment and sensory abilities is combined with an understanding of learning principles that effect changes in behavior. Early in this century, both Yerks and Hediger emphasized repeatedly the need for captive animals to have social and physical stimulation. Only in the past few decades, however, have these ideas been accepted. Every animal needs differing enrichment techniques that suit their behavioral characteristics. There are some ways in which to avoid animal enrichment hazards.
Many zoos work extremely hard to modify their enrichment programs to fit each individual specie.
For example, the Oregon Zoo has a large number of enrichment programs for its animals to keep them occupied during the day. All the animals receive several feedings a day instead of giving them all their food at once in the morning. The animals are also provided with toys, such as boomer balls, logs, branches, browse, ropes, barrels, etc. Training is also a part of the enrichment program. Another zoo that has been working on enrichment ideas is the San Diego Zoo.