As we have learned, when someone loses an object and it has no siman on it – no distinguishing mark that the owner would be able to identify – we assume that there is ye’ush (literally “despair,” i.e. that the owner of an object gives up hope of recovering it) and the finder would be allowed to keep it. On our daf we learn that there are situations where a person will have ye’ush and despair of recovering his property, even if there is a siman on it. Rabbi Shimon ben Elazar teachers that in a case where a person saves something from the hands of a wild animal like a lion, a bear, a tiger, etc. or if he saves it from the ocean or from a flowing river, the finder can keep the object because the owner gives up any hope of recovery.
The Gemara tells a number of stories that support and clarify this ruling. In one of them we learn about a dayo – a type of bird – which stole a piece of meat from the meat market and threw it among the palm trees on someone’s property. The finder went to Abaye to ask what he was obligated to do with this meat, and Abaye ruled that he could keep it. In explaining Abaye’s ruling the Gemara argues that being taken by the dayo would be considered like something lost at sea, where we can assume ye’ush by the owner.
The dayo of our story is identified as the Milvus migrans – the Black Kite – a bird of prey that is found throughout the world. These birds eat small animals and carrion. They often live in close proximity to cities and are even found in densely populated areas, where they are daring enough to swoop down and take meat from humans, whether it is offered to them or not.
One other issue dealt with by this Gemara is why the meat is considered to be kosher, given that we lost sight of it and the bird may have taken it from anywhere. The Gemara concludes that someone would have had to have watched it from the time it was taken until the time it was dropped if it is to be considered kosher.