As spring approaches, billions of birds take to the skies on a journey to their breeding grounds. But before they take off, they undergo some fascinating changes to prepare their bodies for the long migration ahead. Here's a look at how birds transform themselves: ➡️Increased Fat Storage for Fuel: To power through long journeys, birds need a lot of energy. Before they set off, many species go through a process called hyperphagia, where they eat constantly to bulk up on fat! ➡️Muscle Growth: Much like athletes in training, birds bulk up their pectoral muscles - the muscles that power their wings. These muscles grow help birds maintain the stamina they’ll need for hours (or even days) of flight. ➡️Shrinking Internal Organs: Some birds shrink some of their internal organs to reduce weight. This helps them become lighter and more aerodynamic. ➡️Hollowing Out the Bones: Birds have lightweight hollow bones, but during migration, some species further reduce their bone mass to shed weight....