How do musk oxen survive extremely cold Arctic winters?

Musk oxen (Ovibos moschatus) are highly adapted to survive the extreme cold of the Arctic through several physiological and behavioral strategies:

• Insulation: They possess an exceptionally thick coat consisting of long, dark brown hair that reaches nearly to their feet. Beneath this outer layer is a dense, insulating wool known as qiviut, which provides superior protection against freezing temperatures.12
• Body Size: As large herbivores, their size provides an adaptive advantage; a smaller surface-area-to-volume ratio reduces the rate at which body heat dissipates into the environment.2
• Energy Conservation: Musk oxen are specialized for conserving energy during the winter. They store significant amounts of fat during the summer months, which they use to supplement their diet when forage is scarce.1
• Metabolic Support: This stored fat is also vital for female musk oxen, as it supports lactation for calves born in late winter or early spring, before the snow has melted to reveal fresh vegetation.1