For the source text click/tap here: Beitzah 10
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Generally speaking, animals are considered muktzah on Shabbat and Yom Tov. That is to say, farm animals whose normal activities are associated with melachot – activities forbidden on those days – cannot be used. Thus, in the event that an animal is to be slaughtered for food on Yom Tov, it must be prepared or set aside for such use prior to the beginning of the holiday.
Our Daf discusses one who selects birds before Yom Tov in order to slaughter them on Yom Tov. The Gemara cites the Mishnah later (on 10a) in which Beis Shamai says that one who selects the birds must pick them up and shake them; it does not suffice merely to name them verbally. Beis Hillel permits one to designate the birds for use on Yom Tov merely by naming them verbally.
If one designated black doves before Yom Tov and on Yom Tov he only found white doves, or if he designated white doves and found black doves on Yom Tov, or if he designated two doves and on Yom Tov he found three doves, all the doves that he found are muktzeh.
We explore the use of the dove as a metaphor in ancient religion, mythology and even as logo for the OU!
Thinking about the back dove vs the whote dove I was reminded of "Little Gidding" a poem by TS Eliot who used the dove as a dark image for the German bombers that rained death on England during WW2 "After the dark dove with the flickering tongue"...