The climate activists targeted the conservation charity on Tuesday, to some people's surprise.
More than two thirds of the public also fear the government won't meet its climate change commitments.
According to the Living Planet Report 2018, animal populations have declined by 60% on average since 1970. The major study by the World Wide Fund for Nature (WWF) calls on heads of state to step up and fight for our planet.
“We are the first generation to know and the last that can do anything about it."
WWF is tracking pink river dolphins in the Amazon using satellite technology after scientists successfully tagged six river dolphins in Brazil, Colombia and Bolivia.
"Now is not the time to be silent. Find good news sources, get educated, read: that's what makes you powerful."
The global wildlife population is expected to drop 67% by 2020.