What caused a massive die-off of penguins off South African coast?

The penguins perished by the thousands for a simple, agonizing reason: a lack of food.

In two key colonies off the coast of South Africa, the vast majority of the breeding birds probably starved to death over an eight-year period because of a collapse of their food supplies, according to a study published Thursday.

The findings by a team of researchers from the South African government, the University of Exeter and other universities adds to the growing body of evidence about a central threat to the survival of African penguins, which have seen their numbers plummet and are now considered “critically” endangered.

Scientists focused on Dassen Island and Robben Island, where populations of the small bird, with its braying calls and distinctive black-and-white tuxedo markings, were decimat