Trumpeter Swan (Cygnus Buccinator)
As juveniles, trumpeter swan cygnets transform from little white fluffballs...
...to brown-tinged adolescents...
...to the brilliant white plumage of adults. All this takes about a year.
Another indication of an immature trumpeter is the orange beak, rather than the black beak of an adult.
If you want to find all 8700 photos of swans, just do a Dreamstime search with keyword "swan." To narrow it down, you can use the latin name "cygnus," or narrow your search even more by entering "cygnus buccinator."