Memory whiz. Dolphins, such as Kai, remember each other’s whistles for decades. (Inset: The spectrogram of Kai’s signature contact whistle.)

Jason Bruck

Dolphins hunted to pay for brides

If you want a bride in a few Solomon Island villages, you need to pay with necklaces of dolphins’ teeth. And the price has shot up alarmingly since 2004, from about $0.14 per tooth to $0.68 in 2013—as has the number of dolphins slaughtered for this purpose, scientists report today in Royal Society Open Science. The increase in animals killed—at least 1500 pantropical spotted dolphins, 159 spinner dolphins, and 15 bottlenose dolphins in 2013—raises concerns about these small and genetically unique island populations and the animals’ welfare, the scientists say. The hunts take place at the island of Malaita. After spotting dolphins, hunters in 20 to 30 canoes (pictured) paddle into a U-shape formation around the animals, and then smack stones together under water, creating a sound barrier and forcing the dolphins toward shore. The hunters then spear the dolphins, killing as many as 700 in 1 day—which is likely unsustainable and causes great suffering to these social species, the scientists say. In 2010, the Earth Island Institute, an environmental organization in San Francisco, California, managed to stop the hunt in exchange for financial support, but the agreement broke down in December 2012. The scientists suspect that the interrupted hunts may have driven the price of dolphin teeth higher. Catch records from the Fanalei villagers show that they have killed a minimum of 15,454 dolphins between 1976 and 2013. Although the International Union for Conservation of Nature does not consider the spotted, spinner, and bottlenose dolphins endangered, the scientists say the organization’s classifications don’t reflect what is happening to these insular populations—which, they say, urgently need monitoring and management.