First off I can see why you are up set, you don't want to loose any birds. People who just open a door and let dogs run are total jerks to everyone around and even the dogs.I would not go and kill it even if you are within legal rights to do so. You could be in trouble with the neighbors in ways you don't want to think of. What if this is a one time event and the dog got loose by accident. But now on to retribution. If you were staying there I would say electric fence as a cheap and effective way to drive them off. Air soft guns pack a good punch that would hurt them enough they would not come back and you could use the ones with paint to mark the offender if they return. I would save this for last however because the sting of a pellet should drive them off and I can't say what the laws are and you might get in trouble for one with paint on it from the SPCA or just neighbors doing little things you could not prove, you are renting so outsiders do not need a war.
