There's nothing his mother can do, but watch. The pup is safe as long as she stays where the reef runs right up to the beach, and avoids the orcas' attack channels. The unlucky ones provide a grim lesson. ......

The survivors grow more wary. While the sea lions are still young, Mel and Maga can catch up to 16 a day. Blood ties run deep with orcas, and most grow up in tightly knit pods centered on the females. Maga belongs to a separate band from Mel and Dona Blanca, and her group spans four generations. Polygamous, the females mate with several males. So the paternity of their children is unclear. Pregnant for 17 months, they give birth to monster sized, 180 kilogram babies. They nurse for up to two years, and may stay with Maga and the other mothers for the rest of their lives, letting out a series of whistles and grunts, they tell each other where they are, and what they're doing. Each group has its own, distinct set of calls, like dialects the young learn from their elders in an orca form of home schooling. Cooperation, communication and the ability to learn make them successful hunters. Given their prowess, a face-off between an orca and a sea lion might seem like an uneven fight. Killer whales are the largest members of the dolphin family, and adult males like Mel can weigh six tons, and measure six meters. But behind those sad looking eyes beats the heart of a formidable opponent. In open water, sea lions are a challenge for orcas to catch. Extremely agile, they change direction in the flick of a flipper. Recognizing an orca's fin, adults seek safety high on the beach. They need to eat 130 to 180 kilograms every day, or at least three sea lion pups each. Mel has honed his skills over the years, making a kill on 60 percent of his attempts. But with each attack, the pups become that much wiser and harder to catch. When Mel charges up the beach, he's not making a blind rush, he's using all of his senses. Orcas have good eyesight, at least equal to a sea lion's, both in and out of the water. Like other dolphins, Mel and Maga can use echolocation to hunt. But sea lions may have learned to recognize the echolocation's distinctive clicks. So, at Peninsula Valdes, orcas run silent. Instead, they rely on another powerful sense - their hearing. Detecting which direction a sound is coming from, Mel can pinpoint a sea lion's location without ever seeing it. However, the conditions have to be just right. If the surf is too heavy, or the wind blows in from the sea, it overwhelms the sound made by the sea lions. Mel can't pick out the distinctive audio signature of a pup scraping across the pebbles. He has to wait for the seas to calm. Hunting the beach is just one strategy orcas use to catch prey. They feed on at least 100 different species. In the open ocean, they can charge through the water at 48 kilometers per hour, chasing down even the swiftest prey. In confined spaces, like the Norwegian Fjords, orcas herd schools of herring into tight balls, called carousels. They flash their white bellies to startle the fish and stun them with their tails. In the Antarctic, seals often rest on ice floes. Orcas, swimming in tandem, create a wave large enough to wash off their prey. Hunting cooperatively, they even overpower animals as big as grey whales. Separating the calf from its mother, they take turns dunking it until it weakens and drowns.