The American robin has an extensive range, estimated at 16,000,000 km 2 (6,200,000 sq mi), and a large population of about 320 million individuals. No, a bird is not just a bird. As baby birds grow, there are specific names that refer to the changes; nestling, hatchling, or fledgling. These different names denote changes in plumage, proportions, behavior, and the care they require. And by the way, many baby birds are born nearly bald. These altricial babies grow their feathers quickly after hatching, but require more parental care to stay warm and healthy till they do. Is Mother Nature wonderful or do you find these hatchlings repulsive in the looks department ..lol.