Rabbi Dayan was learning the daf in his study when his phone rang.

“Hello, this is Shmuel,” said the caller. “My children found some eggs in our backyard. They did shiluach haken (the Jewish law that enjoins one to send away a Kosher mother bird before taking her young or her eggs) with the chickens and brought the eggs home. Can we eat them?”

“Eggs? Shiluach haken? Chickens?” repeated Rabbi Dayan, bewildered. “What are you talking about?”

“My children, Yaakov and Yosef, were playing in our backyard today,” explained Shmuel. “We have a large open property, with trees and lots of grass. I was resting in the house, and the kids burst in, waving two eggs! ‘We just did shiluach haken and took these eggs,’ they said. ‘Can we eat them?’ they wanted to know.”

“‘Where were the eggs?’ I asked them. ‘These look exactly like regular chicken eggs.’

“‘Yes, there were a couple of chickens roaming around the backyard,’ said Yaakov. ‘Then we saw this hen sitting there on the grass, in the corner of the yard. We shooed the mother hen away and took the eggs. That was shiluach haken, wasn’t it?’”

“Usually, shiluach haken does not apply to domesticated birds,” Rabbi Dayan interjected, “but that’s a side point (Y.D. 292:2).”

“In any case, I put the eggs in the fridge,” continued Shmuel. “Can we eat them?”

“As far as kashrus is concerned, you can eat them, provided they are clearly chicken eggs,” replied Rabbi Dayan (Y.D. 86:2). “The question, though, is one of hashavas aveidah (returning lost items). Do you have to return the eggs to their owner?”

“Return the eggs?” asked Shmuel. “Who owns chickens around here?”

“I heard that Dov Shechter recently acquired a few chickens for kapparos on Erev Yom Kippur,” replied Rabbi Dayan. “They’re almost certainly his.”

“Still, if the owner lets his chickens roam freely,” asked Shmuel, “do I have an obligation of hashavas aveidah to return them?”

“If the owner lets his hens roam freely, you have no obligation to expend effort to return them or their eggs,” replied Rabbi Dayan. “However, Mr. Shechter’s chickens are usually locked up and must have slipped out, so you are required to do hashavas aveidah also on their eggs. Only if the hens escaped and ran away wild, so that he could not catch them, would the hens become hefker (see C.M. 261:4; Rema 259:7).”

“Funny story, isn’t it?” commented Shmuel.

“There’s a fascinating story like this in the Gemara (Taanis 25a) regarding Rabi Chanina ben Dosa,” said Rabbi Dayan. “A person left two hens outside his door and his wife found them. Rabi Chanina told her not to eat the eggs they laid but to look after them. As the number of eggs and subsequent chickens increased and became difficult to handle, Rabi Chanina sold them and bought some goats.

“Some later time, the person who left the hens passed by and inquired about his lost hens. Rabi Chanina ben Dosa verified that he had simanim (identification of the lost item), and gave him the goats that he had amassed!”

“Wow!” exclaimed Shmuel. “Is a person really required to tend to lost items to such a degree?”

“No,” answered Rabbi Dayan, “but Rabi Chanina was known to be extremely pious and acted in a manner beyond the requirements of halacha.”

“What is required in such a case?” asked Shmuel.

“The Mishna (B.M. 28b) teaches that if you find an animal that needs to be fed, but produces, such as hens — you are allowed to use the eggs in exchange for tending to the hens,” replied Rabbi Dayan. “Even so, you are not obligated to tend to them for more than a year. Other animals, which are more difficult to tend to, have a shorter period.”

“What if I found roosters, which do not lay eggs?”

“You have to tend to them for only a short time and then can sell them and return their value,” said Rabbi Dayan. “Otherwise, the cost of feeding the roosters for an extended time would almost negate the value of returning them (C.M. 267:22-24).”