Founded in 1892, Barcelona Zoo is part of the fabric of the city. But what should its role be in the 21st century? The zoo's director, Antoni Alarcón, and zookeeper Núria Moreno Gutiérrez, argue that zoos are essential for protecting biodiversity, but animal rights activist Rosi Carro of the ZooXXI group says that more changes are urgently needed. Norbert Bilbeny, ethics professor at the University of Barcelona gives his view of how the relationship between humans and animals should be. Cristina Tomàs White and Gerard Escaich Folch join Lorcan Doherty to discuss the past, present and future of the zoo. This week's Catalan phrase is 'a pas de tortuga', literally 'at a turtle's pace', it's used to describe something that moves very slowly!