Northern and southern resident orcas have different hunting patterns.

According to a new study from the University of Washington and NOAA Fisheries, northern and southern resident orcas who live in the Salish Sea have different fish hunting patterns.

The northern resident orca’s population has slowly increased. However, southern resident orca numbers are still dangerously low. Both types of killer whales eat salmon and other fish. Their favorite snack is a big chinook because “they’re lipid rich, and they pack the biggest bang for the buck,” according to Jennifer Tennessen, a UW researcher and lead author of the study.

Typically, when killer whales hunt, the group travels to a foraging habitat, individually dive down to capture fish, then share with their family, Tennessen said.