User blog comment:Mckrongs/Monster Hunter 4 for the Nintendo 3DS/@comment-2014385-20131003184128/@comment-5460283-20131004010551

Aldath, They will only leave if you do not do enough damage to them. This is actually a good mechanic because it makes sense and if you don't want to fight the monster currently in the Forest you could just wait for it to leave then hunt the next one.