If the situation arises that makes sending away the mother bird halachically possible, BUT the person on the scene who sees the mother and nest has absolutely no desire or need for the eggs or chicks, should that person try to send away the mother bird anyway? And to take the eggs anyway? If so, why? And if he has no obligation, would he get "mitzvah points" for doing this anyway?
We discussed this in our Insights to Chulin 139:3.
In summary, there is a dispute whether one is obligated to perform the Mitzvah when he happens upon a bird's nest but does not need the eggs or chicks. Some hold he is obligated, some hold he is not obligated but that he *does* fulfill a Mitzvah if he sends away the mother bird, and others hold that he should *not* do it if he does not need the eggs.
Most contemporary Poskim rule that there is no obligation to send away the mother bird when one chances upon a nest and has no need for the eggs, but one nevertheless fulfills the Mitzvah when he does so.
if it is to learn rachmanus and one has no need for the eggs,,why would it then be a mitzvah,,,and isn't that Bal Tashchit? Is the Chok aspect enough to cancell out these known values?
I believe that we address the issues of Rachmanus and Achzariyus in the Insights to the Daf. See particularly the piece in which we discuss the Zohar's words.
There is no Bal Taschis, because nothing is being ruined. (Contrary to popular belief, most birds do return to their nests when shooed away, or when the eggs are touched. Try it out.) Even if the mother never returns and the eggs never hatch, it is not Bal Tashchis because it *was* used for a constructive purpoise -- for a Mitzvah.
All the best,