One topic that I'm interested in is gibbons. A "gibbon" isn't one specific animal; the name refers to a family of apes
consisting of 24 species, 4 of which are extinct. As that would imply, gibbons as a whole are endangered.
Gibbons live in a variety of subtropical/tropical rainforests within Southeast Asia. Here's what some look like:
To learn more about gibbons, you can see the Wikipedia page for them here: