Scientists from the National Oceanographic and Atmospheric Administration made the observation after monitoring the marine mammals as they traveled more than 5,000 miles to visit the tropical waters off southern Brazil before swiftly swimming back to Antarctica 42 days later.
“The whales are traveling so quickly, and in such a consistent track, that it is unlikely they are foraging for food or giving birth,” NOAA researcher John Durban said.
“We believe these movements are likely undertaken to help the whales regenerate skin tissue in a warmer environment with less heat loss.”
Durban points out that the yellowish coating of algae often observed on the skin of the marine mammals is noticeably absent when they return from their warm-water trips.
The researchers published their findings in the journal Biology Letters.