In Following Papa’s Song, by Gianna Marino, a curious whale calf named Little Blue prepares to migrate. “It is time?” Little Blue wonders. “Listen for the other whales,” Papa explains. “When you hear their call, we’ll know it’s time to go.” Later in the story, Little Blue wants to know about Papa’s call, asking, “When I am big, Papa, will I still hear your song?”
Papa replies: “Yes, Little Blue. If you listen closely, you will always hear my song.”
I choked up a little as I read that line to my six-year-old daughter, who is growing up so fast, as children always do, it seems.
Following Papa’s Song is a beautiful and poignant picture book that captures a special relationship between a father and his child. I wish I could leave it at that, but facts have an awful way of infecting my enjoyment of fiction, and as I was reading this book to my daughter, I kept thinking: Shouldn’t Papa really be Mama?
To find out, I read a couple of studies on baleen whales (which include blue whales). I learned that my hunch is probably right, but the answer might not be so simple. It turns out that we don’t know that much about the social dynamics, reproduction, or parenting of blue whales because their “oceanic tendencies and low numbers” make it difficult to study them (Lomac-MacNair & Smultea 2016). What we do know is that:
- They tend to be solitary creatures, though they do sometimes form small groups;
- We have only observed males produce songs; and
- We have only observed females parenting calves.
So, in real life, a blue whale calf would probably have a relationship with their mother, not their father. However, what I’m wondering about now is how researchers identify the sex of the whale they’re observing.
I’m not a marine biologist, so perhaps this is a silly question, but it’s what came to mind as I read a couple of studies on the subject. A large portion of the information we know about whales seems to come from the gruesome whaling industry. I’m not sure what information they gathered, but they may have noted that whales killed with calves were typically female, a conclusion that is consistent with human gender stereotypes. Whatever the reason, modern observational research seems to assume that whenever two blue whales are together, and one is larger than the other, they are a mother-calf pair.
For example, in Reproductive Parameters of Eastern North Pacific Blue Whales Balaeonoptera musculus (linked below), the researchers explained their methodology like this:
Blue whales were individually identified using photos of the flanks and backs of both sides. Females were identified as cows (i.e. lactating) due to the presence of a calf, which in turn was identified by its relatively small size (half the size) and positioning in synchronous swimming pattern while accompanying the female during several consecutive surfacing sequences in the same sighting over approximately an hour.
That sounds reasonable. However, it’s worth noting that researchers in another study I read, one on humpback whales (also baleen whales), were surprised to learn that two of the whales they identified as female because they appeared to be with calves turned out to be genetically male (amusingly, the researchers punctuated this finding with an exclamation point!). (Barendse et al. 2013).
So, maybe a blue whale calf could follow their papa’s song? It doesn’t seem likely, but who knows what we’ll learn about this magnificent species in the future.
PS. My kids have been interested in blue whales ever since they saw the preserved blue whale heart in Toronto earlier this summer (they went with my sister and my Dad, who is standing with them in the picture). The heart is from a whale carcass that washed ashore in Newfoundland in 2014. To learn more about this exhibit, see Blue Whale (Royal Ontario Museum) & The Painstaking Process of Preserving a 400-Pound Blue Whale Heart.
Barendse et al (2013) Mother Knows Best: Occurrence and Associations of Resighted Humpback Whales Suggest Maternally Derived Fidelity to a Southern Hemisphere Coastal Feeding Ground, PLOS ONE, available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3857176/pdf/pone.0081238.pdf
Lomac-MacNair & Smultea (2016), Blue Whale (Balaenoptera musculus) Behavior and Group Dynamics as Observed from an Aircraft off Southern California, ANIMAL BEHAVIOR & COGNITION, available at: http://animalbehaviorandcognition.org/uploads/journals/9/01.Feb2016-Lomac&Smultea-final.443.del.pdf
MacDonald et al (2006), Biogeographic Characterisation of Blue Whale Song Worldwide: Using Song to Identify Populations, J. CETACEAN RES. MANAGE. 8(1): 55-65, available at: http://cetus.ucsd.edu/Publications/Publications/McDonaldJCRM2006.pdf
Sears et al (2013), Reproductive Parameters of Eastern North Pacific Blue Whales Balaeonoptera musculus, ENDANG SPECIES RES 22:23-31, available at: http://www.int-res.com/articles/esr2014/22/n022p023.pdf