Many hummingbird species have adapted to live at high altitudes in the tropical and subtropical montane forests of the Andes Mountains of South America. Genetic mutations include evolved hemoglobin with enhanced oxygen-binding properties allow them to keep up their intense pace even in habitats that lack oxygen. According to ornithologist, Christopher Witt, hovering hummingbirds 10x more energy than a human athlete in their prime. The Andes range are home to more than 300 species of hummingbirds.
Information adapted from article titled, “How do hummingbirds thrive in the Andes?” The Guardian