Rashi says on the gemorahs answer of why a bird who you need to say Hava Metsuda Vinitsodeno is not chayav for tsod is because it comes back to its cae at night and therefor even if its not in its cage and its outside you can trap it and its no problem.
So my problem is, whats the reason why ypu can trap it even if its outside? it can and will run away from you if you grab at it. so whay isnt it assur?
Reuven Kasierer, silver spring, USA
Tzad is one of the more difficult Melachos. In every Melachah (except Hotza'ah which is called a Melachah Geru'ah) some change has taken place through the Melachah, however by Tzad seemingly only the venue has changed. However, we must say, that by Tzad before it is "caught" it is an animal on the loose, while once it is caught it is ready for use. Therefore, an animal which will return is considered an animal that is "caught" (i.e. accessible) and not "on the loose" (or inaccessible).