What is the noun in this sentence However some manage to survive by hibernation or migration?

The noun in the sentence "However some manage to survive by hibernation or migration" is some.

Here's why:

* Some is a pronoun in this sentence.

* Pronouns often act as nouns, standing in for a noun phrase.

* In this case, "some" refers to a group of unspecified animals or creatures.

Let me know if you have any other sentences you'd like to analyze!