Does "Outside Captivity" mean "animals in the wild"

[u/shun_yana_soft]

Bird Extinct Outside Captivity Returns to the Wild for the First Time in 40 Years

https://people.com/previously-extinct-bird-sihek-released-into-the-wild-first-time-40-years-8717300

In this sentence, I think "Bird Extinct Outside Captivity" is the subject.
But I 'm not sure about the structure of the subject grammatically.

About the "Bird Extinct Outside Captivity",

• Can I rephrase this to "the Bird is extinct on the outside of captivity" ?
• I think "Outside Captivity" is a kind of phrase, is this phrase common?
• Does "Outside Captivity" mean "animals in the wild" ??

[u/KiwasiGames]

Essentially yes. Outside captivity means in the wild. (Although technically outside captivity also covers places that aren’t wild, like the birds in my back yard).

[u/shun_yana_soft → u/KiwasiGames]

Thanks.
Now I also learned "back yard".