Orcas have been caught on camera for the first time hunting with Pacific white-sided dolphins.

They believe their findings can improve the future welfare of the iconic mammals when held in captivity.

Common dolphins - among the ocean’s most abundant mammals - are living for an average of 17 years rather than 24 years in the 1990s.

The marine mammals could be suffering from a form of Alzheimer’s disease when they get washed up on beaches.