Mr Livingstone was in Chester to speak at the zoo-organised event, involving staff and delegates from zoos in 42 different countries, including the USA, China, Costa Rica and Rwanda.
He also visited the zoo’s new Hot Pink Flamingos exhibition – which aims to inspire people to take an interest in the impact of climate change on the world around them.
Ken Livingstone with staff and penguins at Chester Zoo with keeper Karen Neech and Director General Mark Pilgrim.