Tweet, tweet. Who doesn’t love the trills and warbles of birds? God equipped many of them to produce complex calls and sing melodious refrains. Some people trap, smuggle, and exploit birds—all because of their beautiful songs.

Francis Gurahoo flew from Guyana to the United States. Inside his luggage, customs officials discovered 34 live finches (colorful, seed-eating songbirds). The birds were squeezed inside plastic hair curlers. Gurahoo planned to sell them for their voices.

Owning songbirds isn’t illegal. But officials know bird competitions involve illegal gambling. According to law enforcement, people buy finches to enter them in singing contests. Then they bet on the outcomes.

In New York City, contests often take place in city parks. Two birds compete in “bird-racing.” It’s not what you think. Bird-racing is speed-singing.

Bird owners stick two birds in cages. Judges count as the competing birds sing. Every pause counts as one song. The first bird to 50 songs wins. Another similar contest involves most chirps-per-minute.

A winning bird “can sell in excess of $5,000,” Special Agent Gabriel Harper tells The New York Post. He also notes that finches from Guyana are the most desired because of their beautiful voices.

New Yorkers aren’t the only folks obsessed with songbirds. (For another example, read “Freeing Colombia’s Songbirds”) In Indonesia, wild songbirds are disappearing. They’re captured and sold for bird-singing contests.

High-prize, high-pressure competitions in Indonesia mean bird handlers will do almost anything to enter the best songster they can find. They use fake leg bands, phony papers, and whatever else they need to misrepresent wild birds as ones they’ve brought up by hand.

Catching wild birds is illegal. But it’s cheaper than breeding them. Poachers catch birds by putting glue and nets on tree branches where the birds live. “I do this work to survive,” a poacher named Afrizal told The New York Times. “Of course, I feel guilty. If they die, I feel even sadder.” But he doesn’t stop.

Bird-singing contests have become so popular that they attract thousands of onlookers. On the Indonesian island of Java, government officials even judge so-called “chirping competitions.” Judges scored birds on how many voices they can mimic or how quickly they can sing. Cash prizes run between $1,200 and $20,000.

Marison Guciano is founder and executive director of a bird protection group. He says Indonesian poachers seize more than 20 million songbirds each year. “Indonesia’s forests are silent, millions of birds have moved from the forest to the cities,” he says, “and now [it’s] easier to find and listen to the sound of birds singing in cages than in nature.”