How OceanXplorers Captured Never-Before-Seen Whale Behavior

Deep in the Caribbean, roughly 50 miles off the north coast of the Dominican Republic, a research vessel called the OceanXplorer is scanning the surface. Its crew includes James Cameron, deep-sea scientist Zoleka Filander, shark biologist Melissa Márquez, ocean tech innovator Eric Stackpole, and former Royal Marine Aldo Kane. They are looking for one of the largest animals on Earth, and they are about to witness things no one has seen before.

Every winter, thousands of humpback whales migrate up to 5,000 miles from their feeding grounds in the North Atlantic to this small patch of ocean. They come here to breed and give birth. The warm, shallow waters above submerged mountain tops create a perfect nursery for newborn calves. Scientists believe this location is the main reason mothers travel such enormous distances to raise their young. But the whales spend most of their time beneath the waves, and the details of their lives have remained largely hidden.

From the helicopter above, Eric spots a group of whales quickly. There is a single adult female surrounded by males. What looks like a peaceful gathering can suddenly erupt into a frenzied pursuit. Eric describes it as a "fight club." The males weigh more than trucks, and they pound against each other while speeding through the water at high speed. The female leads the pack, and if a male loses his position behind her, the chance to mate will be up for grabs. Sometimes the males push each other completely out of the water. White water sprays everywhere.

To get a rare underwater perspective, Aldo and cameraman David free-dive to 70 feet without tanks. Free diving is the closest a human can get to being a mammal in that environment. In one breath, Aldo swims into the whales' world. He admits he is always apprehensive when getting in the water with big animals. "We are in their territory, in their environment, and we are tiny in comparison," he says. "If you get on the wrong side of one of those pec fin slaps or a tail slap, then it's going to be game over."

One group they encounter seems totally at ease. There is a female surrounded by five males, and the mood is completely different from the fight club on the surface. One male moves closer and gently blows a stream of bubbles onto her belly. This intimate encounter has rarely been seen. Whale scientist Asha de Vos analyzes the footage back on the ship. She identifies the female by her asymmetrical tail pattern and watches her interact with one group for about 15 minutes, almost as if a bond is forming.

Then the researchers find the same female with a completely different group of six males. She has slipped away and found new suitors. Eric compares it to online dating, swiping through profiles trying to find the right match. Asha agrees that the female is taking her time, looking for the ideal mate to produce a strong calf. The scientists realize that female humpbacks are far choosier than previously understood. They rotate between groups, performing similar intimate behaviors until they find the right fit.

Meanwhile, marine mammal scientist Mithriel Mackay has developed an intriguing hypothesis about why so many whales come to this specific location. From her aerial surveys, she noticed whales tucked into bowl-shaped edges on underwater mountains, almost like natural amphitheaters. She wondered if the whales were using these features to amplify their songs, making it easier to reach potential mates across greater distances.

To test this theory, Zoleka descends to 250 feet in a submersible. The OceanXplorer has mapped the sea floor and discovered mountains rising up to 2,000 feet, with plateaus stopping just below the surface. These bowl-shaped edges are roughly the size of football stadiums. Zoleka and Mithriel place microphones at various depths within the bowl while Eric and acoustic scientist Kerri Seger set additional hydrophones in shallower water above.

They play a recording of humpback song through a waterproof speaker at the same depth where male whales typically sing. Back on the ship, Kerri visualizes the acoustic data in the hololab. The first sound signal moves away from the speaker as expected. Then they add the echo from the amphitheater wall. The readings jump dramatically. Everything turns red, registering at 90 decibels, an increase of 11 decibels from the echo alone. That extra sound energy is enormous. The researchers have proof that the underwater terrain really does amplify a whale's song by as much as 11 decibels. This could be a major reason why humpbacks travel thousands of miles to this particular spot.

While mating season plays out, females that became pregnant here the previous year have returned to give birth and rear their calves. The shallow waters provide the perfect nursery. Asha describes it as a "big schoolyard" where mothers teach their young life skills before the long migration back to the North Atlantic. A mother has no food available here. She has not eaten for five months. Yet she must pour all her energy into her single calf, producing roughly 50 gallons of rich milk every day. The calf is entirely dependent on her.

Asha and David approach a mother and calf slowly, hoping to capture the intimate bond between them. The pair seem undisturbed by their presence. The calf, only a few weeks old, bonds with its mother through touch. It stays near the surface because it can only hold its breath for a few minutes. One moment, the calf became curious and approached Asha and David. "All kids are curious," Asha says. "But then a mother's instinct is to make sure she is protecting their calf." The mother made a u-turn underwater, and the calf knew immediately it was time to leave. Cameraman David notes that a protective mother is essential for a calf's survival.

When a mother and calf finally leave the nursery grounds and enter deeper waters, they face new dangers. The team plans to tag a mother and calf as they begin their migration north. Eric spots a pair on the move and contacts the tagging team. Then something else appears in the water ahead of them. Orca, also known as killer whales, are heading straight for the mother and calf.

These are the ocean's apex predators, a family of adults and juveniles that need to eat. They move like wolves, surrounding the pair. The mother keeps the calf on her back to protect it from attacks from underneath. The calf's belly is the most vulnerable spot. The baby falls off the side repeatedly, trying to get back to its mother. Eric watches from above and describes the scene as both magnificent and terrifying. "I can just picture the emotions this mom has," he says. No one has ever filmed an orca hunt like this in these waters before.

Mithriel changes the plan and asks the team to tag an orca instead. This could provide the first-ever scientific insight into a hunt in this area. Kerri manages to attach a tag with four suction cups to the lead female.

The damage kept spreading far beyond the original intelligence failure.