"If the 'leader' gets disorientated because of parasites in brain or other disease, [she] may lead the group into dangerous shallow areas," he said, adding that calls from stranded individuals can draw others in, who also strand.
Another theory is the presence of nearby seismic testing and military sonar, which has been correlated to marine mammal strandings in the past. When intense pulses of sound are emitted into the water column during activities like naval war exercises or oil exploration, the acoustic waves can drive marine mammals to the shore, or even kill them at sea.
Without proper necropsies on the animals, however, it's nearly impossible to know if sonar or seismic testing were to blame. But, said Ken Balcomb, whale researcher and Executive Director of the Center for Whale Research, it can't be ruled out.
"Stuff happens; but, that does not mean that there was not a reasonable potential for seismic testing to be the cause," he told The Dodo in an email. He estimated that an acoustic blast at the level of 145 decibels would be enough to suspect seismic testing.