An endangered orca that spends time in Pacific Northwest waters is still carrying the corpse of her calf one week after it died.

Experts with the Whale Museum on San Juan Island have been monitoring the 20-year-old whale, known as J35, or Tahlequah, since her calf died shortly after birth last week Tuesday. For days now, the whale has been balancing the dead calf on her forehead or pushing it to the surface of the water.

Researchers are now growing concerned for the whale's health as she has probably not eaten since she went into labour last week. J pod, the mother's clan, has been staying with her while she carries the calf around.

Jenny Atkinson, the Whale Museum's executive director, says the orca was still carrying her dead calf Monday afternoon.

Atkinson says the orca and her pod are going through "a deep grieving process."

The calf was the first in three years to be born to the dwindling population of endangered southern resident killer whales, with only 75 members. The crisis with J35 comes even as another member of J pod, J50, appears to be starving to death as the chinook salmon the animals depend on rapidly decline.

Deborah Giles, research scientist for University of Washington Center for Conservation Biology and research director for nonprofit Wild Orca, told the Seattle Times: "I feel so sad for that family. And for her mental state she must be in anguish. What is beyond grief? I don't even know what the word for that is, but that is where she is."

- AP