Knock.
and I don't know the laws in Maine, but I take biosecurity seriously. An at large chicken in poor condition wanders onto my property, I'm culling it before I risk it bringing some disease or parasite into contact with my flock.
Quarantine is for birds I WANT to join my flock, not for adopting other people's problems as my own. Even with 30 acres, if its carrying fowl pox, mosquitoes can easily carry its illness from it to my birds. [again]. Other diseases it may carry can contaminate my grounds for months,
Quicker, less risk, and more cost effective to humanely end it.