A flamingo is a common noun, you don't have to capitalize this word.
Common noun
Proper noun
Eagle is a kind of bird not a name of bird therefore it's a common noun.
No bird is a common
Unicorn is a common noun.
Common because they are not names.
"Park Avenue" is a proper noun, because it is a place. Proper nouns like this should always be capitalized.
Robin is a proper noun when it is a name, but common when it is the bird. Proper nouns are the unique names of people, places, or things. Common nouns are the words for general things. If a common noun is part of a name, it becomes a proper noun. Pronouns always replace proper and common nouns.
Common
It is a proper noun, because it is the name of a specific thing.
proper
Proper noun
Pencil proper or common noun
it's a common noun. a proper noun would be Spider-Man.