Chullin Daf 140 צולין דַף 140

A non-kosher bird sitting on kosher eggs is exempt from שילוח הקן, because "צפור" implies a kosher bird. A kosher bird sitting on non-kosher eggs is also exempt, based on Rav Kahana’s derashah: "תקח לך" – take for yourself, implying your personal consumption, ולא לכלביך – but not if they must be fed to your dogs, i.e., a tereifah. Rav Kahana’s derashah explains a Baraisa which teaches that if the mother bird is a tereifah, it is subject to שילוח הקן (since the mother is from a kosher bird species), but if the chicks are טרפות, he is exempt, since he cannot take them to eat them. Rav Hoshaya asked: if someone inserted his hand into a nest (under the mother bird) and shechted the lesser part of the chicks’ סימנים, is he obligated in שילוח הקן? Since the chicks would become tereifah if he would leave them, do we say he is exempt, or כיון דבידו למגמר שחיטה – since it is within his ability to complete the shechitah and permit them, he is obligated? The Gemara concludes: תיקו.

Rebbe Yirmiyah asked: מטלית מהו שתחוץ – does a cloth between the mother bird and its eggs constitute a חציצה between them, exempting it from שילוח הקן because the mother is not sitting directly on the eggs? He asked several other questions about a possible חציצה: do detached feathers constitute a חציצה? Are ביצים מוזרות – unfertilized eggs, which themselves do not obligate שילוח הקן (since they cannot produce chicks), considered a חציצה between the mother and fertilized eggs? If they are a chatzitzah, שני סדרי ביצים זו על גב זו מהו – what is the halachah in the case of two rows of eggs, one atop the other, where he only wants to take a lower egg? If a male bird is on the eggs (which does not obligate שילוח הקן), and the mother bird is sitting on top of the male bird, what is the halachah? The Gemara concludes: תיקו. Rebbe Zeira asked: if a dove is sitting on eggs of a תסיל (a kosher bird similar to a dove), or vice versa, is it subject to שילוח הקן?

The next Mishnah states: היתה מעופפת – if [the mother bird] was hovering above the nest, then בזמן שכנפיה נוגעות בקן – as long as its wings are touching the nest, one is חייב to send it away, but if its wings are not touching the nest, he is exempt. A Baraisa darshens: "רובצת" ולא מעופפת – the passuk discusses a mother bird “sitting” on the nest, but not one hovering above it. However, if its wings were touching the nest, he is obligated, because instead of using "יושבת", the more common word for sitting, the passuk says "רובצת", which connotes crouching. Rav Yehudah says that if the mother bird was suspended בין רובדי אילן – between the branches of a tree above the nest, then כל שאם תשמט נופלת עליהם – any case where she would fall upon [the eggs] if she would slip off, one is obligated to send it away. Another Baraisa exempts a hovering mother bird, even where its wings touch the nest, and the Gemara explains that this applies where its wings touch the nest from the side.