sentenece Frangments The great horned owl, an endangered species.
Easiest way to identify a sentence fragment is often seeing where the verb is. You have no verb.
Another way is to imagine someone walking up to you in the street and saying it. "The great horned owl, an endangered species." Then they walk away. The first thing you would think, after thinking, "That was strange" is "What the heck did he mean by that? What was his point?"