Tahlequah, the Southern Resident orca who carried her dead calf for 17 days in 2018, is mourning the loss of another newborn, raising concerns about her health.

The calf was born in late December. Observing researchers noted unusual unspecified behaviors by mother and calf that led them to worry for the young whale’s health.

The mother orca, known as Tahlequah or J35, has been seen carrying the body of the deceased female calf since Wednesday, the Washington state-based Center for Whale Research said in a Facebook