Why 150,000 penguins have died in Antarctica – video explainer

An estimated 150,000 Adelie penguins living in Cape Denison, Antarctica, have died after a giant grounded iceberg forced them to trek 60km to the sea for food. In 2010 a colossal iceberg measuring 2900sq km became trapped in the bay, rendering the colony effectively landlocked. The iceberg had apparently been floating close to the coast for 20 years before crashing into a glacier and becoming stuck

• 150,000 penguins die after giant iceberg renders colony landlocked