New research shows the marine heat wave that spread from California to Alaska starting in 2014 caused common murres to starve to death.

St. Lawrence Island, home to two native villages in the region, is also the summer home of several migratory seabird species, including kittiwakes, auklets, murre and shearwaters. Over the last several years, though, the bird colonies on the island have been shrinking, and no one has been able to determine why.

In the fall of 2014, West Coast residents witnessed a strange, unprecedented ecological event. Tens of thousands of small seabird carcasses washed ashore on beaches from California to British Columbia, in what would become one of the largest bird die-offs ever recorded.

A network of more than

Carcasses examined so far have shown no indication of disease, and tests are pending for harmful algal toxins. Seabirds have been found emaciated and starved, and changed ocean conditions may have affected prey.

In a paper published Wednesday, researchers theorize the die-off is at least partially attributable to the changing climate.