Improving bird levels is one of the main ways to further progress in The Birders. By doing so, not only will you gain the necessary experience to unlock new national parks, but you will also obtain better features to capture birds up close and earn more points.
You can improve each bird once you have acquired enough copies. The copies required to improve them can be obtained from packages and the store, but only for randomly obtained birds.
Each bird can be improved up to a certain level, depending on its rarity.
Before proceeding with the improvement, you can see all the anticipated benefits. Birds can be improved in exchange for coins. The rarer and higher level the bird is, the more coins will be required. Once you run out of coins, you can improve birds using feathers.