SILLY WHALES

We’ve never really known a lot about blue whales (Balaenoptera musculus); yes, despite our long history near and on the sea, blue whales’ tremendous size, and there having been hundreds of thousands of them occupying the oceans prior to industrial-scale whaling and still tens of thousands persisting through to today.

For example, humans have only observed blue whale births twice — the first time near South Africa back in 1911 and then once more in 1946, in a harbour in the northeast of Sri Lanka. Also uncommon is spotting blue whale mothers and their calves. Forever, researchers have wondered where the young of these behemoths are born and raised. They talk of the “mystery of the missing blue whale calves” and being “unable to determine if there are specific breeding-ground regions for blue whales.”

The research suggests blue whales have a relatively high rate of pregnancy. This contrasts with the very low rate of mother-calf sightings. To reconcile the discrepancy many explanations have arrived: that blue whales have lower birth rates or higher calf mortality than we thought or could reasonably be anticipated or maybe that young are ushered into nurseries in the safety of the deep ocean and beyond our observation. Well, turns out there may be a far simpler explanation.

The journal of Endangered Species Research just published work on this very matter by whale scientist Trevor Branch, from the School of Aquatic and Fishery Sciences at the University of Washington. There, Branch forwards a fabulous hypothesis suggesting the reason we never spot blue whale mother-calf pairs is because they give birth shortly after departing their Summer feeding grounds in the far poles and wean their calves over the following year in the tropics, right before returning. And when do researchers prefer to do their fieldwork? Well, they have a strong preference for conducting research in the Summer — precisely when there are no births or wee whales around. 

The research suggests “Observed rates are too low to be explained by low fetal survival, low calf survival, low birth rates, or calf separation from mothers, although mother-calf pairs might avoid higher-density regions where field studies are concentrated…” This new model, which would also double as a theory for blue whale breeding, predicts the mother-calf population proportion would peak in Winter, at around 8-9%, and reach a low of maybe 1-2% in Summer, when school is out and PhDs have time off to do fun stuff like whale spotting.

Bwahahaha!

This reminds me of that old bit about scientists seeking to photograph ants for their new behavioural genetics textbook. They spend weeks and weeks out in the field trying to catch any members of any colony exhibiting this specific act. Unable even to observe one instance, never mind capture it on camera, the researchers conclude that, clearly, these silly ants have never read about the behavioural genetics of hymenoptera and were unaware of what proper ant behaviour looks like.

Yes. Exactly.