“Calf” in this context refers to a dolphin calf, not a baby cow that happened to fall in the water.
Several adult tucuxi dolphins (Sotalia guianensis) were seen attacking a newborn calf. Six adults separated the calf from its mother, then while four of them kept the mother away, the other two repeatedly rammed the calf and held it under water. Researchers saw the mother a few days later, but sadly not the calf. Speculation is that the calf was killed in the hope of inducing the mother to become sexually receptive.
Infanticide is relatively common in many mammal species, but has not been seen very often in whales and dolphins. Prior to this case it had been reported twice in bottlenose dolphins, but this is the first case seen in tucuxi dolphins.
Tucuxi dolphins live either in the Amazon basin, or off the coast of Brazil up to Nicaragua.
More information from the BBC website.
