Humpback whale calf with adults (IMAGE) Smithsonian Tropical Research Institute Caption Humpback whales travel to shallow tropical waters to give birth and then return to their feeding grounds in cooler ocean waters. Researchers think that most orca attacks on humpback whales involve calves in their first year of life. Credit Eduardo Estrada Usage Restrictions Credit: Eduardo Estrada License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.