This is thanks to the special energy storage mechanism in the body and the way they choose to move like a marathon runner.
Some birds, including the arctic tern, can travel more than 30,000km per year.
Botanists have nicknamed this bird the “Champions of Migration”. The average Arctic tern weighs just over 100 grams and each year they migrate from one pole to another.
Swallows live in pairs, breeding in the summer in the Northern Hemisphere, and when winter reaches the North Pole, it migrates south to the South Pole in flocks.
Easier to understand, this bird flies by sunlight in the true sense, to avoid the cold of the Antarctic winter, these migrations include a non-stop flight of more than 8,000 km across the Indian Ocean.
Where do birds get their energy for the journey?
Most animals mainly break down various carbohydrates and glucose to provide them with energy.
But studies reveal that for birds, it will convert fats and lipids into fatty acids as a source of energy for them.
Before the migration season, birds will switch to a diet of lots (hyperphagia) and foods rich in fat. In fact, warblers have been known to double their body weight before entering each migration.
But overeating alone cannot explain their rapid fattening. These birds also do a great job of absorbing nutrients from food.
The fat they store amounts to 50-60% of their body mass. Fat is stored in fat cells, located just under their skin.
Poultry fat cells can store up to 95% of their volume as fatty acids. They can also store fat in tissues other than muscle and in the liver (similar to glycogen storage).
Besides, birds can also store fatty acids in the liver, which are then converted into triglycerides. These triglycerides are transported out of the liver in the form of VLDL (very low density lipoprotein) consisting of cholesterol (10%), triglycerides (70%), protein (10). %), other fats (10%).
They acidify the fat to fuel the wing muscles that help the bird fly, which is then converted back into fatty acids. The enzyme lipase, produced by the endothelial cells of the flight muscle, mediates this reaction.
How do birds use this energy?
Long-distance migratory birds are like marathon runners, choosing endurance over speed. In fact, this helps birds reduce energy use wherever possible.
Many birds take off by rapidly flapping their wings, which consumes the most energy during migration. Take-off is anaerobic and birds use stored glycogen (a type of carbohydrate) to initiate flight.
However, in long-haul flights, birds do not flap their wings much.
Theo Science ABC