A man was caught at New York’s JFK airport last weekend trying to smuggle dozens of South American finches into the country, a bird that Guyanese immigrants covet for chirping but officials fear could spread disease, officials said on Thursday.

About 70 finches were found hidden inside a shipment of hair rollers at John F. Kennedy International Airport on Saturday when a U.S. Customs and Border Protection agriculture specialist inspected the unidentified male passenger’s luggage. Some of the birds had died enroute.

The birds may have been destined for sale to Guyanese immigrants for a game that involves betting on how often the finches chirp per minute, said Customs spokesman Anthony Bucci.

“They may ultimately wind up as a pet, but within the Guyanese community that is the primary purpose,” Bucci said.

The passenger was not admitted into the United States and was sent back to Guyana, Bucci said.

The finches were quarantined and euthanized by the Animal and Plant Health Inspection Service (APHIS) Veterinary Services, an agency of the U.S. Department of Agriculture. Photos on the CBP’s Twitter page showed the birds squeezed into individual hair rollers with small nets covering each end.

The birds can spread infections such as avian influenza, commonly known as bird flu. A 2015 bird flu epidemic resulted in the culling of 50 million commercial turkeys and chickens and $850 million in damage, according to CBP officials.