This time of year, humpback whales make their annual trip to the warm waters of the South Pacific to mate. Today"s image finds us swimming alongside a humpback mother and her young calf near the Polynesian island chain of Tonga. There are six main humpback populations in the southern Pacific, and this pair is part of the one that"s often called the "Tongan Tribe." The humpbacks of the Tongan Tribe return each year from their feeding grounds off Antarctica—a journey of more than 4,000 miles. Through November, the cows will stay in this region while their newborn calves grow strong enough to make the trek back to the cold Antarctic waters where their main food source—the small crustacean called krill—is abundant.