Who is obligated in this mitzvah?
- This mitzvah may be performed both by men and women . 
Which Birds are included in this mitzvah?
- Only kosher birds are eligible for this mitzvah. When determining which birds are kosher to eat, we require a clear mesorah, tradition, that our ancestors ate these birds. However, when determining which birds are fit for the mitzvah of Shiluach Hakan, we may rely on the physical signs of kosher birds as delineated by Chazal.. Therefore, we can distinguish among three categories of birds: 1) Kosher birds which we eat and may use to fulfill the mitzvah, for example certain species of pigeons, doves, geese, and ducks; 2) Birds which exhibit kosher signs , yet do not have a clear mesorah, for example sparrows, robins, cardinals, and orioles. These birds may be used to fulfill the mitzvah, but they are not considered kosher to eat; and 3) Birds which are definitely non-kosher with which we should not perform Shiluach Hakan. This includes eagles, ravens and other birds of prey.
- It is important to note that the mitzvah is only performed when sending away the mother bird. This is usually the bird that is resting on the nest at night. Therefore, night is the optimal time to perform the mitzvah.
- Common Birds Fit for Shiluach Hakan by Geographical location include:1)American Robin-North America 2)Canada Goose- North America 3) European Robin Europe, Eretz Yisroel 4)Mallard Duck- North and Central America, Europe, Asia 5)Mourning Dove – North and Central America 6)Northern Cardinal- Eastern and Central U.S., Central America7)Palm Dove – Eretz Yisroel, Africa, Europe 8)Pigeon – Worldwide 9)Sparrow- Worldwide
When is the mitzvah applicable?
- The mitzvah may only be performed before the chicks develop the ability to fly on their own (approximately two weeks after hatching) 
- The mitzvah must be performed on an ownerless nest. . Therefore, if one has a nest in one's property the mitzvah may not be performed. However, some authorities hold that one may declare the nest hefker (ownlerless) in front of three non-related people, thereby allowing the mitzvah to be performed. 
- The mitzvah may not be performed on Shabbos or Yom Tov. 
- There is no bracha recited prior to performing this mitzvah. One reason given for this is that the bird may fly away of its own volition after the brocha is recited, and the mitzvah will not have been fulfilled. 
Steps in fulfilling this mitzvah appropriately
- Upon approaching the nest one should first intend on sending away the mother bird. One doesn't need to pick up the mother and send her away, but rather, any stimulus which can cause the mother to fly away is sufficient.
- Once the mother bird has flown away, one must take the eggs or chicks.Even if the mother bird is watching, one still fulfills the mitzvah. To perform a halachic acquisition, they should be lifted to a height of three Tefachim (about 12 inches). Upon completion of the mitzvah, one may put back the eggs or chicks and need not keep them.
- After one takes the eggs or chicks, they may be declared hefker by the one who acquired them and then returned to the nest. After the mother bird returns, another person may fulfill the mitzvah. In this way, the same nest may be used over and over again.
- Sefer HaChinuch 545
- Ramo Y.D. 82:3. The Torah lists twenty-four species of non-kosher birds; all others are deemed kosher by the Torah. However, our translation of the Hebrew names for birds is not always accurate.
- Responsa Minchas Elazar 3:43
- Briefly, kosher birds that are sitting on a branch place three toes in front and one in back, non-kosher birds place two in front and two in back. Kosher birds also have a crop and their gizzards can be peeled. In general, birds of prey are not kosher (Chulin 59a). Another sign of kosher birds is that their eggs are not symmetrical; one end is wider than the other
- Shulchan Aruch Y.D. 292:7.
- This is derived from the pasuk which states, “Ki yikarei” -- when you happen upon a nest. Chulin 138b, Shulchan Aruch YD 292:2
- If the mother has not yet left the nest since laying her eggs, all would agree that one may fulfill the mitzvah on his property (Shulchan Aruch Y.D. 292:2). Since the owner himself is forbidden to take the eggs while the mother is incubating them, the property cannot acquire on his behalf at that point. However, it would be extremely difficult to determine that the bird has never left the nest.
- Responsa Chasam Sofer O.C. 100. One issue is that of muktzah, and another is that according to the reasoning of the Zohar cited above, it is improper to arouse Heavenly distress on Shabbos.
- Most authorities state that no brocha is recited. See Birchei Yosef Y.D. 292:1 citing Rishonim. However, Aruch Hashulchan 292:10 interprets differently and holds a brocha is recited.See also: Responsa Binyan Tzion Hachadashos 14. See Pischei Teshuva Y.D. 292:2.
- Rashi (Chulin 141b), Chazon Ish (Y.D. 175:2). ;However, many understand the Rambam (Hilchos Shechita 13:5) as ruling that one must pick up the bird with his hands and send her away. (Aruch Hashulchan Y.D. 292:6. See, however, Responsa Binyan Tzion Hachadashos 14 and Sefer Kan Tzipor pg. 30 ). Many contemporary gedolim were seen and photographed using a stick, and that is the common custom.See Responsa Torah Lishma 278.
- Chazon Ish (Y.D. 175:2). See Chofetz Chaim in Sefer Hamitzvos Hakatzar 74 and Aruch Hashulchan 292:4. However, in a minority opinion, Responsa Chacham Tzvi (83) holds that one need not take any offspring. He interprets “Habanim tikach lach” as optional, similar to “Sheshes yamim ta’aseh melachtecha.” Even if there is only one egg or chick, the mitzvah may be fulfilled, though the Torah uses the plural “Banim” (Shulchan Aruch Y.D. 292:1).
- Based on Beiur Halacha (O.C. 366 s.v. tzarich), they could alternatively be held entirely in one’s hand to create a kinyan chatzer.
- Shiluach Hakan, Feldheim, pg. 65, quoting contemporary poskim.
- Under certain circumstances it is possible that if a child fulfilled the mitzvah no one else may fulfill the mitzvah on those same eggs or chicks since a child cannot effect hefker. (See Mishne L’melech Hilchos Mechira 29:1 that hefker m’daas is considered da’as acheres makneh. Therefore if an adult was mafkir and then the child was koneh, the child could not be mafkir.)
- If the eggs cool down too many times, they may no longer be viable (University of Arkansas Division of Agriculture). The mitzvah is not fulfilled on non-viable eggs.