A loud rumble and giant billows of dust interrupted an otherwise serene day in Central Park on Thursday as hundreds of cream-colored carvings of dragons, Buddhas and horses awaited their public execution.

Onlookers waved paper fans reading “Protect their home.” They cheered as sculptures and jewelry made from elephant tusks were carried on a conveyor belt and dropped in a pulverizer.

Brian Hackett, an animal-welfare activist from New Jersey, patiently awaited his turn to choose a carving from a table to be destroyed. For him, the mood was solemn.

“Every piece, no matter how polished, represents a beautiful animal that was slaughtered,” Mr. Hackett said.