Issue link: http://digital.canadawide.com/i/170490
science Normal activity Murray O'Neill Rushing water drowns the high-pitched cackle of an eagle. The cubs sit in the intertidal zone, licking each other's snouts now and again as if to wipe away the pungent odour surrounding them. They watch their mother lean on her right paw and plunge her left into the moist sand. A veteran clam digger, Marsha zeroes in on her mark. She sticks her snout into the hole, snaps her teeth around the mollusc, draws it out, tosses it on the beach, and smacks her right paw down on her prey, her left claws slicing it open. Marsha slurps the morsel of protein. The trio combs the beach for a few hours. Marsha digs a hundred or so holes, tossing back dozens of clams, filling her belly, teaching her cubs how to forage—that is, when they're not busy ambushing each other and avoiding adult males. • • right: Sub-adult male grizzlies playfully spar. When they are full adults, the male bear's battle for a mate intensifies. opposite: A grizzly bear rests on a log in Glendale Estuary, Knight Inlet. Brad Hill above: A male grizzly digs for butter clams in an intertidal zone. 26 B r itish C olumbia Magazine • fa ll 2013 A sow with cubs leaves the rich habitat to males and other females. During the breeding season a male might cannibalize cubs, forcing the female into estrus—akin to a hormonal panic—and making her ready to breed again. Males spar for females, the biggest and baddest winning the right to mate. Hamilton's genetic analysis also reveals that the big boys dominate the gene pool. To improve their odds of fatherhood, males might play jailer to their mates, challenging them if they try to leave. The notion of a super submissive sow seems far-fetched, though. Cubs from the same litter often have different fathers. "The theory is, she wants to go with the biggest, the strongest," Ciarniello says. In other words, she sees a better option walk by, and she takes it. Breeding bears play the mating game for about six weeks, so intent on keeping the species going that meals become secondary. Mothers, meanwhile, are like moms everywhere, for the two or three years that grizzly cubs stick around for, or one to two years for black bear cubs. They guard their cubs as they play and socialize, fend off enemies (bears, wolves, and the odd golden eagle that might fly off with a black bear cub), and model appropriate behaviour. Ciarniello says she knew two grizzly cubs that hung around with mom for four and a half years. "I think they're more social than we give them credit for," she says. Female bears might even spend time with their mothers or grandmothers, since their territories often overlap.