The zoos and nature conservation organizations affiliated with the Association of Zoological Gardens (VdZ) are calling for a reversal of the trend on the Red List of the International Union for Conservation of Nature (IUCN) – from red (threatened) to green (recovery). The goal: to give endangered species a future again.

With the international 'Reverse the Red Day', zoos and nature conservation organizations worldwide are calling for a reversal of the trend on the Red List of the International Union for Conservation of Nature (IUCN). "We know that species conservation works – if we pursue it consistently and work together," says Volker Homes, Managing Director of the Association of Zoological Gardens (VdZ). "Zoos make an indispensable contribution to this. They ensure genetic diversity, enable reintroductions, and sensitize millions of visitors to the protection of nature." The Association of Zoological Gardens (VdZ) includes 70 zoos in Germany, Switzerland, Austria, and Spain.

Encouraging success stories

Przewalski's horses were considered extinct in the wild – today they roam the steppes of Mongolia and Kazakhstan once again, thanks to a coordinated European breeding program involving a large number of zoos.

The Moorea tree snail has been upgraded by the IUCN from 'extinct in the wild' to 'critically endangered', a sign that Reverse the Red is possible. The snails from zoo populations were released into the wild on the Pacific island of Moorea near Tahiti. The first adult snails have now been spotted in their natural habitat. Schwerin Zoo coordinates and supports the breeding and release of endangered snail species in the region.

The Vietnamese crocodile lizard benefits from exchanges between scientifically managed zoos. Cologne Zoo plays a key role in the conservation breeding program and has already raised almost 50 second-generation offspring. Twelve animals were returned to Vietnam in fall 2025 and are now ready for the first reintroduction program.

Zoos in Europe and around the world are getting involved

Species conservation is also tangible in Germany: zoos are involved in projects and support the return of endangered native species such as the lynx, bearded vulture, and bald ibis.

In Switzerland, the association zooschweiz, an umbrella organization of Switzerland's scientifically managed zoos, is a member of the European Association of Zoos and Aquaria (EAZA) and the International Union for Conservation of Nature (IUCN). They are involved in a wide range of projects.