Thousands of penguin chicks died in Antarctica last year as a result of the increasing ice melt. The record low level of Antarctic sea ice at the end of 2023 led to breeding failures in a fifth of the continent's emperor penguin colonies, according to the British Antarctic Survey (BAS). The study was published in the journal Antarctic Science on Thursday, which is World Penguin Day It used satellite data to reveal the extent of the impact of early sea ice breakup on the penguins' breeding cycle.