HRS §142-99
What to do if you find a lost animal
If you take control of a lost animal, you must tell the owner (if you know them) or the local humane society's animal control officer, and give the animal to them. If you don't, you can be fined up to $500.
everyone
The statute, as written — Lost or rescued animals; penalty
(a) Except as otherwise provided in section 143-10, any person who exerts control over a lost animal shall immediately notify the owner of the animal, if known, or an animal control officer of the local humane society chapter of the county in which the animal is found and release the animal to the owner, animal control officer, or humane society chapter. For purposes of this section, "exert control" means any act which constrains an animal including leashing, chaining, or otherwise confining an animal. (b) Any person who violates this section shall be fined not more than $500.
Sections this one refers to
§143-10 What to do if you find a stray dog
LawTrove is not legal advice. The summary above is a computer-generated restatement — the authoritative text is the official version linked above.