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 GERRIT S. MILLER'S paper, “Some o'¦'o¦ hitherto unpublished photographs and measurements of the Blue Whale” (Proc.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 ...