Some birds, though, like orchard orioles or summer tanagers, need until the following spring to acquire their breeding-best adult dress, At the extreme, bald eagles need five years to mature.

Most baby birds stay in the nest for at least 10 days in the nest before flying off on their own. For birds like Baltimore orioles, bluebirds and rose-breasted grosbeaks, this happens typically ...

Baby birds grow quickly; their energy demands are high. Another possibility is that one of the adult birds was injured or killed, leaving the surviving parent with an impossible feeding job.

It will take a baby starling two to three weeks to grow its first adult feathers. it takes anywhere from 15 and 21 days for starling babies to become fully feathered. At that point, they are ready ...

• Juvenile. It takes about nine months for juvenile birds to acquire full adult plumage and become capable of breeding, but they’re essentially on their own. • Adulthood.

Things get even more confounding from there. Through poop samples, Piirto was able to determine what each nestling and adult bird was eating.

PRAGUE -- Zookeepers in Prague sometimes have to become puppeteers to save newborn birds rejected by their parents. This was the case for a lesser yellow-headed vulture chick hatched three weeks ago.