Humpback whales whale watching migrate to Cabo Verde from feeding grounds in Norway and Iceland to mate and give birth to their young. The season lasts for about three months till the end of May. Then whales start the 40-50 day journey back to the north. Population of Cabo Verdean humpbacks is very small - only about 300 individuals while the entire North Atlantic population is around 10,000. Waters of Sal Rei Bay in Boavista Island are of critical importance to these animals, as many of them return here year after years.