Sending away the Mother Bird from the Nest

There is a dual imperative in the mitzvah of shiluah ha'ken: firstly, one cannot take advantage of the motherly instinct to protect her young. It is something so profound, and deep, that for you to hover over the nest in wait, for the mother to bring food to her young, only to take her for your own consumption, is antithetical to any sense of what it means to be a Jew. 

Secondly, and the more complex part, is the prohibition of taking the young in the mother's presence. Much has been said on this matter to the extent that I feel that I have little to add. The early commentators weigh in on the rationale behind the prohibition, and the Rambam and Ramban take slightly different views as to whether or not one should seek logical underpinnings behind the commandments we have been given. The Sefer Hachinuch interestingly sides with the Ramban, and states that were one to chalk up the commandment as a form of internalizing the value of mercy, then, something would be lacking in our full understanding of the Torah's command. The Zohar, of note, I learned from Rabbi Moshe Shapira Z"L, shares that the reason is very different than what we would have otherwise thought; when the mother bird flies away, disconsolate over her young, then Hashem remembers our pain as a people, steeped in the morass of exile, and has compassion, remembering that we are destined to return. 

Another eye-opening idea that comes out of the Chinuch is that shiluah haken aims to teach us that God doesn't want species to become extinct. Killing a mother bird and its young on the same day - the same is true, he writes of killing a mother and its calf on the same day - is tantamount to wiping out an entire species. (Fascinatingly, the Chinuch writes that the world was created with a certain number of species, and none have become extinct, testifying to God's greatness.) The Chinuch adds that when one has compassion on a mother bird, and its young, he will be blessed with children, the equivalent of long life, in the form of midah k'neged midah.

I myself once wanted to fulfill the mitzvah, and I called up our rabbi, Rabbi Baruch Rubanowitz, a dayan; a nest was nestled on our window sill, with a number of eggs. He instructed us that vis a vis fulfillment of the mitzvah, one would actually be required to need/want the eggs; I shared that I'd be more than happy to make an omelet, sunny-side up eggs, and he said acutely that they're so small, and if I understood correctly, the more compassionate thing would be to leave them alone. If you have eggs readily available, and don't need the eggs, the Torah's allowance to take them applies when it would have been of use to you, and not for the arbitrary fulfillment of a mitzvah that can only be fulfilled when a whole suite of conditions and stipulations are met, i.e. coming across it incidentally, or unexpectedly, and likewise, ensuring that it's the mother you shoo away, and not the father, as the mother and father take turns etc. 

As an aside, an interesting trivia question. The prohibition of eating forbidden foods only applies to eating foods in their normal way/manner. For example, one doesn't typically swallow foods whole, without tasting them. There is one food prohibition class/genre which is punishable by lashes even if one were not to eat it in the typical way..