It’s been 10 years since the advent of Endangered Species Day on May 15th, and for this anniversary, more than 200 zoos had some very special plans: get rid of endangered species for good.

Not really, of course — they’re not killing animals off or anything, they’re just giving visitors a glimpse of what the world would be like if these animals no longer existed, raising awareness of a global problem, according to a Science Times report.

At one zoo in Akron, Ohio, an exhibit where rare Sumatran tigers could be viewed by an awed public was covered up. Visitors could peer through a few holes, but the limited access was meant to shake people into the reality of a future planet without some of these remarkable creatures.

Science Times noted that a zoo in Dallas had kept visitors from spying its African penguins — except for people who pledged to eat sustainable seafood and conserve energy.

It’s all part of a global effort by scientists and conservationists to get people to pay attention to the world around them and how we are losing species at an alarming rate — and once they’re gone, they’re gone. There’s no bringing them back.

At the heart of the issue is concerns about global warming and how that will affect the global ecosystem. Since humans are believed to be the caused behind it due to increasing carbon emissions, efforts to convince the public to scale back on such harmful activities as wasteful energy usage take front and center at events like these.

Endangered Species Day is meant to help people of all ages learn about how to protect endangered species, and what steps an individual can take to make a difference.