We are continuing in siman 1. The Chayei Adam discussed the first three conditions for tzad, that the animal is b’mino nitzad, the animal was not already sick enough to be considered trapped, and that the act of tzad confines it in a way that it is easily accessible to the human.
Regarding the third condition, we need to define making the animal readily accessible. He explains that the definition of readily accessible is that it could be caught in one chase. In other words, if the average person could chase an animal for 10 minutes before needing a break, the animal must be in an enclosure in which it could be caught within 10 minutes in order to be considered tzad. The size of this area will depend on the size and speed of the animal. For example, if chasing a small rodent, even a small area may not necessarily allow for catching the animal, due to the cracks and crevices it can hide in. For example, bringing a bird which cannot fly into an enclosed courtyard would be considered tzad.
Although the Chayei Adam digresses to discuss whether this definition is the correct understanding of the Gemara, practically, it is the accepted definition.
The Chayei Adam continues, and writes that a tzippor dror, which is a small, fiercely independent flying bird, is not considered trapped even in a house. Even with all of the windows and doors shut, it will continue to flitter away from the human and will not be accessed in one chase. Thus, chasing this bird into a room or a house would not be tzad on a Torah level. Nevertheless, it will be considered tzad on a derabanan level.
It is important to note that if something is considered trapped on a derabanan level, it is not considered trapped as far as the Torah is concerned. If so, when it is moved into a stronger level of trapping, it will be considered an issur deoraysa.
Summary
Regarding the third condition for tzad, that the animal be confined in a way in which it is easily accessible, “easily accessible” is defined as getting caught in one chase. This space will depend on the size and speed of the animal in question.
Something trapped on a derabanan level is not considered trapped from a Torah standpoint. Moving something from a derabanan trapping to a Torah level is assur deoraysa.
