Members of the Spanish environmental activism group Futuro Vegetal have thrown fake blood and oil on exhibitions at the Egyptian Museum of Barcelona.
They say they are denouncing the "inaction" of the governments gathered for the COP27 talks in Sharm el-Sheikh, Egypt.
The man and woman sprayed the cage with fake petroleum, then the walls with fake blood, using plastic bottles of Coca-Cola.
They then unveiled a large banner reading "COPCA COLA" - a reference to one of the conference's official sponsors.
Many environmental NGOs are critical of the soft drink giant for activities they consider to be polluting the world, in particular, the massive production of plastic bottles.