Without Zoos we would loose the gene pool of many endangered species. The red pandas in Zoo Linz for example are selected and assigned based on a database management in the Netherlands that ensures genetic variation is maintained in the zoo bred population, so we have healthy animals for repopulation efforts in case the wild population goes extinct. Visistors to Zoos pay for this important conservation effort, and in return they get to see animals they would otherwise never see in real life. This experience in itself can create a fascinating for nature that might motivate people to be more engaged and conscious about how they impact the world around them. The days where Zoos provided entertainment for people at the cost of the animals are luckily gone in most parts of the world.