The Sperm Whales of Dominica – The sperm whale, one of the largest animals in the sea, is at risk because of noise pollution, ship strikes, and plastic trash. Cecilia Vega dives in off the coast of Dominica, where hundreds of sperm whales live year-round, to observe these mysterious mammals and understand the efforts to protect the vulnerable species. Michael Rey is the producer.Monkey Island – Correspondent Lesley Stahl reports from Cayo Santiago, also known as Monkey Island, off the coast of Puerto Rico, and home to roughly 1,800 rhesus macaque monkeys whose DNA is a 94% match to humans. Stahl examines one study set to determine the impact of environmental crises on the longevity and overall health of the macaques and what the inhabitants of Monkey Island can reveal about climate-related trauma and survival. Ayesha Siddiqi is the producer.Hanging On – 60 MINUTES' Sharyn Alfonsi reports from Costa Rica on sloths and their superpower of slowing down. Alfonsi examines how these mammals have mastered the art of survival for more than 60 million years and the new threats of climate change to the species. Guy Campanile is the producer.