Decadal Decreases in the Frequency (Pitch) of Baleen Whale Vocalizations Blue whales are the largest living mammal species. Their long, slender bodies can reach lengths of 30.5 m (100 ft) and weigh up to 160 tons. Blue whales produce stereotyped calls, described as pulses, grunts, groans, and moans, which are typically in the 15-40 [...]