Male Caimans Sing to Females for Love

Male caimans have been filmed singing to their prospective lovers as part of new Discovery+ series The Mating Game. Narrated by David Attenborough, the series looks at the different strategies animals use to attract a mate.

In one episode, the crew follows the exploits of caimans, a smaller relative of alligators. This species is found in Central and South America in swamps, marshes, mangroves and lakes. They can grow to around 13 feet in length and weigh around 500 lbs.

In the scene, a male newcomer starts to grunt. He then disappears beneath the surface of the water and starts to grumble, making the water above ripple. The low frequency of the caiman's call makes the water dance. "This song contest may be inaudible to us, but not to female caiman," Attenborough says. "It attracts them from far and wide."

Soon after, the male is seen with a partner.

Jeff Wilson, series producer on The Mating Game, told Newsweek he did not know caimans had a special mating song until the research team told him. "It is an extraordinary behavior," he said. "I have always loved the fact that there is communication going on in the natural world that is outside human sensory capabilities—like little secrets that belong to the animals themselves, and the caimans' subsonic vibration song is one of the best.

"Yes, other crocodilian species do this, but rarely in such a large gathering and in such spectacle."

A male caiman performing a song to attract a female. Discovery+/BBC Studios

He said the unusual conjunction of a prehistoric predator having a gentle, considered mating technique should be celebrated. "[We should] marvel at the fact that these nuanced behaviors around courtship have been happening long before humans walked the earth. Caimans, in fact all animals, deserve to be viewed with wonder and empathy, and once you do so, you realize that our human behaviors draw from the same wells of emotion and technique."

The caiman mating scene took about a month to film. They went during peak caiman breeding season and had to find a way to maneuver safely around these creatures while not disturbing them. They then faced the challenge of predicting a moment that is impossible to hear with the human ear.

Wilson said the series was developed because the courtship strategies of animals are a "treasure trove" of interesting behaviors. "It literally is the greatest competition on earth, with the winners having a stake in future generations of their kind, and the losers fading into the background, and as such it has given rise to some of the greatest behavioral and morphological adaptations in the natural world," he said.

"We knew that wherever we turned our lenses, there would be fascination, surprise and drama. The mating part is by far the least interesting—it is the build up to that moment where the real interest lies."