Hullin, Chapter Twelve, Mishnah One
Deuteronomy 22:6-7 states: If, along the road, you chance upon a birds nest, in any tree or on the ground, with fledglings or eggs and the mother sitting over the fledglings or on the eggs, do not take the mother together with her young. Let the mother go, and take only the young, in order that you may fare well and have a long life.
Our chapter, the final chapter in Hullin, deals with this mitzvah, called letting the mother bird go from the nest (shiluah haken).
1) The law of letting [the mother bird] go from the nest is in force both within the holy land and outside it, both during the existence of the Temple and after it, in respect of unconsecrated birds but not consecrated birds.
2) The law of covering up the blood is of broader application than the law of letting [the mother bird] go; for the law of covering up the blood applies to wild animals as well as to birds, whether they are at one’s disposal or not, whereas the law of letting [the mother bird] go from the nest applies only to birds and only to those which are not at one’s disposal.
3) Which are they that are not at one’s disposal? Such as geese and fowls that made their nests in the open field.
a) But if they made their nests within a house or in the case of Herodian doves, one is not bound to let [the mother bird] go.
Section one: The law of letting the mother bird go from the nest is applicable in all times and all places. However, it only applies to unconsecrated birds and not to consecrated ones.
Section two: The mishnah compares the law of covering up the blood (see chapter six) with the law of letting the mother bird go because both are practiced with wild animals and not domesticated ones. However, covering up the blood is of broader application because it applies to animals and birds, whereas sending the mother bird away obviously applies only to birds. Furthermore, sending the mother bird applies only to birds that are not at ones disposal, meaning they are not house birds. In contrast, the covering of the blood applies to all birds and wild animals.
Section three: If a bird makes its nest in the open field, then it is considered to not be at ones disposal and one needs to send it away before taking its young.
If the birds nest in the house, then when one comes to take them, he need not send the mother bird away. This is probably derived from the word along the road in Deuteronomy 22:6. The same is true for Herodian doves, which refers to the types of doves that Herod used to raise in his palace.