Experts think that climate change may be the culprit.
When water gets warmer -- as it has this year, because of the El Niño weather pattern this winter -- food for sea lions gets scarce. That probably means that mama sea lions spend more time away from their pups looking for food to keep themselves alive. When left alone and starving for long periods, sea lion pups are more likely to wean themselves early.
And when they leave home, they're doing so not just too young to fend for themselves, but already hungry and desperate.
“They’re leaving with a very low tank of gas and when they get over here, they’re showing up on the beach basically ... starving to death,” Justin Viezbicke, a coordinator with the National Oceanic and Atmospheric Administration’s California Stranding Network, told the Associated Press.
Even if rescue groups manage to save most of the pups, this is part of a troubling trend. It's the third year in a row that the pups have washed up in record-breaking numbers, and they show up earlier and earlier.