Is the word humming bird a common noun or proper noun?

The term "hummingbird" is a common noun, as it refers to a general category of small, colorful birds known for their ability to hover and rapidly flap their wings. Common nouns name general items, while proper nouns specify unique names of particular people, places, or organizations. In contrast, if you were referring to a specific species or a named hummingbird, that could be considered a proper noun.