DENVER — Humans aren’t the only species whose members speak to their babies in the womb. Dolphin mamas appear to sing their own name to their unborn calves. New research suggests that dolphin mothers teach their babies a “signature whistle” right before birth and in the two weeks after. Signature whistles are sounds that are made by individual dolphins, which the animals use to identify one another. Calves eventually develop their own signature whistle, but in the first few weeks of life, mothers seem focused on teaching their offspring their signature sound, the scientists said. “It’s been hypothesized that this is part of an imprinting process,” Audra Ames, a doctoral student at the University of Southern Mississippi, said here on Friday (Aug. 5) at the MORE