1. There is a dispute about whether one is liable for inflicting a wound or for burning even though it is considered an act of ruining.
2. An animal is considered trapped only if it does not require more capturing.
3. There are certain animals for which one cannot be liable for trapping, since they are already considered trapped.
4. A person is liable for trapping a deer if he locks the deer in his house (and there is no other opening through which the deer can exit).
5. A person is liable for trapping an animal if he blocks the animal from escaping from the only available exit.
A BIT MORE
1. Rebbi Avahu: One is exempt for any
Melachah he does for a destructive purpose except for inflicting a wound or burning something (see Tosfos DH b'Chovel). Rebbi Yochanan: One is always exempt if he does a Melachah for a destructive purpose, even inflicting a wound or burning something (provided that he does not need the blood from the wound or the ashes from what he burns).
2. Accordingly, locking a bird in a house does not constitute trapping on Shabbos, since it is not trapped. It can still avoid capture by flying out through the windows.
3. The Gemara gives as an example a sick, crippled, or very old deer that does not run away from human contact.
4. A person is liable only for trapping a lion if he puts it into a specially built lion-cage.
5. If he partially blocks the exit and a second person comes and completely blocks the exit together with him, the second person is liable. This is because the second person has effectively blocked the exit completely, causing the animal to become trapped.