In the Pacific Northwest and British Columbia, scientists have been sounding the alarm about the plight of southern resident orcas. Annual counts show that population numbers, already precarious, have fallen back to mid-1970s levels. Most pregnancies end in miscarriage or death of the newborn. They may not be catching enough food. And many elderly orcas—particularly post-reproductive matriarchs, who are a source of knowledge and help younger generations—have died.
Click here for original story, Northern and southern resident orcas hunt differently, which may help explain the decline of southern orcas
Source: Phys.org