Only two blue whale births have ever been recorded in human history, both decades ago. This remains an extraordinary mystery, ...

But across various blue whale populations, high pregnancy rates of 33-50% annually seem to contradict the average 3.1% rate of sightings of blue whales involving mother-calf pairs.

MR. GERRIT S. MILLER'S paper, “Some o'¦'o¦ hitherto unpublished photographs and measurements of the Blue Whale” (Proc. U.S. Nat. Mus., Vol. 66, pp. 1-4, Pis. i ...