New peril for gray whale survival? Predatory orcas spotted in Baja calving lagoon
The gray whales are on the brink of collapse, experts say.
The gray whale population has plummeted by 80 percent in three decades, losing more than three-quarters of its birthrate and its ability to reproduce. And the rate of death has soared: Scientists have recorded more than one hundred attacks of gray whales.
But the gray whales face another threat: an aggressive mating season.
When male orcas begin a mating season in January, gray whale calves are at the most imminent peril. Orca sperm are toxic, killing off the majority of calves before they’ve reached the first few months of their life.
But this year, the mating season is just beginning, and the first recorded male orca-whale attacks of the year occurred this weekend, according to the National Geographic. The Southern Resident Killer Whale, or R-O-A-D, is said to be the first to inflict this type of injury.
“I think it’s extremely rare,” says Dr. Patrick Maynard, a whale biologist at UC Santa Barbara. “It’s pretty unusual to start the mating season with males attacking females.”
The danger isn’t limited to just gray whales, or to orca whales in particular. Researchers from the National Wildlife Research Center in North Carolina say that it’s happening to all cetacean species, with only the sperm whales and bottlenose dolphins showing less aggression.
And as more whales die, more vulnerable calves are born to die, too.
“They’re going to have problems,” Maynard says. A study published in the scientific journal Proceedings of the Royal Society B shows that the number of gray whale deaths doubled after the 2007-2011 decline in calf survival.
The reasons for this are complicated, and we’re still learning. Researchers believe that there are multiple factors causing the gray whale population decline. “So many factors, we don’t