Finches keep showing up at Kennedy International Airport in Queens. On flights from Guyana.

So far this year, customs officials say, nearly 200 of the tiny songbirds have made the arduous journey from South America, stuffed into plastic hair rollers or cardboard toilet paper rolls and hidden in the luggage of smugglers who bring them illegally into the United States.

Sometimes, they are given a little rum before the trip to calm their nerves.

On Saturday, 70 live finches were discovered in the black duffel bag of a Guyanese citizen who, like the other smugglers, was believed to be bringing them to the United States to participate in underground singing contests. Gamblers set the birds against each other and place bets on their chirping skills.

A winning male finch with a good pedigree and track record can sell for up to $10,000, according to a United States Fish and Wildlife Service investigation nicknamed Operation G-Bird.

“They bet on how many times the finches will chirp in a minute, which finch chirps the most,” Anthony Bucci, a spokesman for United States Customs and Border Protection in New York, said on Wednesday. “The most common animal we see trying to be smuggled through the passenger environment are these birds, the finches.”