A member of the endangered Southern Resident killer whale population has been spotted carrying a dead newborn calf in waters off Vancouver Island, highlighting once again the serious reproductive challenges facing the small orca population. Researchers with the Center for Whale Research in Washington state reported that a female orca identified as J31 was seen carrying the calf near Sombrio Point in the Strait of Juan de Fuca, about 96 kilometres west of Victoria. Researcher Mark Malleson encountered J31 and members of her family on Oct. 3. The adult whale was observed moving through the water with the deceased newborn on her nose. Researchers have not been able to determine whether the calf was male or female. They also do not yet know whether it was carried to full term before dying, was stillborn or died shortly after birth. The discovery is particularly significant because J31 has experienced repeated reproductive losses throughout her life. The whale was previously documented carrying a dead calf in 2016 and has also experienced several failed pregnancies.
J31, also known as Tsuchi, was born in 1995. Her only known surviving offspring is J56, a female born in 2019. Researchers say her reproductive history reflects a much broader problem affecting the Southern Resident population. The Southern Resident killer whales are considered critically endangered. Their numbers remain small, making every successful birth extremely important to the population’s ability to recover. Researchers say the cause of the latest calf’s death remains unknown, and there is currently no evidence establishing a specific reason for the loss. However, the death comes against a backdrop of long-standing reproductive difficulties among the Southern Residents. One of the biggest challenges facing the whales is access to Chinook salmon, their preferred and nutritionally important food source. Reduced availability of Chinook can leave pregnant and nursing females without the energy they need to successfully carry and raise calves. Scientists have also identified other pressures affecting the population, including underwater noise from vessels, pollution and the effects of a very small population size. The Southern Residents have experienced several highly publicized cases involving mothers carrying deceased calves. In 2018, another female, J35, became internationally known after carrying her dead newborn for more than two weeks and travelling hundreds of kilometres with the calf. Researchers say such behaviour should not automatically be interpreted as human grief, but prolonged carrying of deceased calves has been repeatedly documented among killer whales and remains an important subject of scientific observation. The latest sighting is also a reminder of how difficult population recovery can be when reproduction is already limited. Even when calves are successfully born, they must survive their first months and years in an environment where food availability and other human-related pressures can affect their chances. For a population numbering only a few dozen whales, the loss of a single calf represents an important setback. Researchers say protecting the conditions needed for successful pregnancies, births and calf survival will be essential to the long-term future of the Southern Resident killer whales. The Center for Whale Research continues to monitor J31 and her family as researchers work to understand the circumstances surrounding the latest loss and track the health and movements of the endangered population.