For generations, ultra-Orthodox Jews have marked Yom Kippur by swinging live chickens over their heads while saying a blessing, then slaughtering the birds as a symbolic way to rid their souls of sins.
Now some rabbis are decrying the practice as animal abuse.
These rabbis say the ritual, along with the cruel conditions the chickens are kept in, violate Jewish law, which has strict rules on the care and slaughter of animals.
Rabbi Meir Hirsch began having second thoughts about the practice, known as kaparot, or atonement in Hebrew, when he noticed chickens squawking in distress in plastic cages near his house.
Butchers "bring the chickens from the farm at night, and they spend all day in the sun without food or drink," said Hirsch, a member of the Neturei Karta ultra-Orthodox sect in Jerusalem. "You cannot perform a commandment by committing a sin."
The tradition dates back at least 800 years and calls for believers to wave a live chicken three times over their heads ahead of the arrival of Yom Kippur, Judaism's holiest day, which begins at sundown Friday. After slaughter, religious Jews often donate the meat to charity.
Jewish leaders across Israel and the United States have called for an end to the practice for years, but leaders of insular ultra-Orthodox communities have been resistant.
The controversy surrounding kaparot stretches back centuries.
Rabbi Joseph Karo, one of the major codifiers of Jewish law, called it a "foolish custom" reminiscent of pagan practices. Since his 16th-century pronouncement, Jews of Sephardic, or Middle Eastern, origin have tended to perform kaparot without animals, sometimes swinging sacks of coins above their heads before donating the money to charity.
Those following Ashkenazi, or European, customs, have continued to use chickens, however.
Hirsch said he now waves a $10 bill above his head instead of a chicken.
While Hirsch's sect of several thousand members in Jerusalem is relatively small, calls for reform are spreading to other streams of Orthodoxy.
Yehuda Shein, a community activist in the Jerusalem suburb of Beit Shemesh, founded an ultra-Orthodox animal rights group last year. This year, about 50 activists from his group, "Behemla," or "in compassion," handed out flyers citing rabbinical opposition to performing kaparot on chickens.
"People doing kaparot think only about holding onto the chicken, and they think they did a good deed of donating the chicken to charity. But they don't understand the pain the animal endured," Shein said.
Shein shudders at factory farming practices that mean chickens spend their lives packed tightly into cages, only to be roughly transported to slaughterhouses by night and neglected for hours on the day of their death.
"Whoever wants to do this ritual can do it on a farm where the chickens roam freely," he said, adding that he wants to improve chicken farm conditions not just for kaparot, but for all days of the year.
Behemla also campaigns for more humane egg and meat farming and has pushed to regulate the fur industry, which supplies the traditional material for ultra-Orthodox hats.
Menachem Friedman, an expert on Jewish religious society in Israel, said replacing chickens with donations to charity is a rising trend in Israel and around the world.
"There is also a very accepted custom in synagogues, that in the afternoon, people bring their money for kaparot, and everyone chooses the charity he wants to support," he said.
Most opposition to chicken kaparot has come from progressive Jewish circles, and modern Orthodox worshippers shun the practice, though Friedman said "there are sprouts of an awakening" now among the very religious.
Still, the vast majority of the ultra-Orthodox continue to transfer their sins to chickens ahead of Yom Kippur, he said.
In an alley of the religious neighborhood of Mea Shearim, dozens of men, women and children milled around plastic cages stacked five high and stuffed with chickens. The local butcher charged about $16 for live birds with bound legs.
Moshe Friedman bought one and gripped its wings with his left hand while he held a laminated prayer sheet with his right. Then he swung the chicken above his head, muttered a blessing, and took the bird to be slaughtered.
Friedman, 21, said he believed the chicken's death saved him from a violent recompense for his own sins.
Miriam Honig, 30, said her husband waved chickens above her head and the heads of their two young sons.
"I think it's good for a child to see this," said Honig of London. "We eat the chicken for a meal, and so now we see the live slaughter."