John Forde of the Tofino Whale Society and Strawberry Isle Marine Research Centre says the calf appears to have been born this week.
He says a group of transient orcas were spotted near Meares Island on Tuesday, and the next morning a newborn calf was swimming with a female orca.
Transient orcas travel along the Pacific coast — sometimes arriving in B.C. from as far away as Alaska and California — while resident orcas stay in southern B.C. and Washington waters.
Forde says any new calf is very exciting because orca numbers are endangered, although the transient population is more stable than the resident one.
He says he isn't sure whether the newborn is male or female but it is quite large, active and swimming close to its mother.