Dolphin mass suicide

26 dolphins were found beached on the Cornwall coast. Because their lungs and stomachs were filled with mud and debris, some scientists are thinking it may have been a mass suicide. This Guardian article, despite its headline, leaves the issue pretty open-ended.

Dolphins are one of the animals believed to be most similar to humans emotionally. They exhibit complex communication strategies with each other and with humans, and are able to negotiate situations that require a good deal of higher order thinking.

I'm not quite sure what to make of this idea of dolphins committing suicide en masse, especially in such a brutal way.