The Rice's whale can grow to 42 feet and is critically endangered, with fewer than 100 left.

The Sri Lankan navy and local villagers rescued more than 100 short-finned pilot whales that became stranded on a beach south of the capital, Colombo.

"While they are still alive and in water, there is certainly hope for them, but as time goes on, they become more fatigued and their chance of survival reduces," said a government wildlife official.

A drop in shipping traffic is reducing underwater noise, so scientists are listening for how whales and other marine life are responding.