March 8 – March 15,2014
Humpbacks are supremely adapted to a life at sea. Their unusually long pectoral fins provide them a grace unique even among the cetaceans, and their sleek forms allow for surprising economy in movement. They can disappear into the distance with only the subtlest flutter of fins, or breach clear of the surface with only a few flips of the fluke. Their enormous power is therefore often understated. Not so in a rowdy group, though: the allure of sex brings out the the most ambitious of efforts, and it is truly exhilarating to see the drama unfold. This week on the Silver Bank we encounter nine
males in amorous pursuit of a female, who without calf is potentially ready to consider a mate (rowdy groups are generally composed of a single female and multiple males, though up to 6% of presumed males have surprisingly turned out to be females). The action is fast-paced, with the female in the lead and the males straining to keep up while outmaneuvering each other for position. At speeds of up to 14 knots, the effort is clearly visible: dorsal fin after dorsal fin arc rapidly above the surface, water streaming from shining backs. Circular fluke prints hover for minutes among the waves, evidence of enormous water displacement as the animals kick off. The effort is audible too, with exhalations so forceful as to sound like trumpet blows. Quiet seas and great visibility mean we are able to see pectoral fins and even flukes raked over competitors, and there are a number of lunge breaches, one whale throwing its tremendous weight atop another. Focused on the female, the males are unconcerned with our presence: we get straight into the thick of things, close enough to see the rawness of wounds, close enough to feel condensation from their blows on our faces, close enough to be hit with spray off a fluke as one whale abruptly changes direction and rams another.
A male humpback’s blowholes after a forceful “trumpet blow”. © Lorenzo Martinez
Another set of encounters this week are just as notable, though of a different sort: we are extremely privileged to spend two full days
with an incredibly patient mom and exuberant calf. Mom spends much of her time either logging sedately at the surface (a behavior seen often in the North Atlantic, but less common in the warmer southern waters), or nestled amongst dense corals just below the surface. The large female calf alternates sleeping below mom’s chin with wide-ranging surface antics, making for some very exciting interactions. Obviously curious, she rises directly towards the swimmers, spinning away at the last moment, then coming back for more. Several times she circles closely around the entire group, inspecting her playmates at close range. In quieter moments, baby pauses briefly to nurse, her mother releasing long streams of fattening milk into the water column (lacking lips with which to suckle, baleen whales ingest viscous milk secreted from mammary grooves on the mother’s underside). Other times, a lovely gesture: baby and mom resting quietly, facing one another and touching nose to nose. A second mother and calf pair sticks around for 3 hours, this baby spinning and turning in far more languid fashion than the other. The surface of the sea is like glass for this encounter, providing mirror reflection to baby’s slow rolls.
© Jean-Francois Chabot
The impressive behaviors don’t stop there: later in the week we come upon a whale positioned head down in the water column, fluke breaking the surface. Getting into the water, we discover him nose to nose with a second whale, a female, her body inverted and pecs spread wide. A third whale (sex unknown) hovers close to the female, or just below her. The scene is incredibly intimate, and just as uninterpretable. What does such positioning imply? Some species of whale regularly position themselves fluke up, but the behavior is unusual in humpbacks. Later, we come upon two mother and calf pairs traveling together, the calves criss-crossing paths and sticking close to each other until we lose them among the corals 15 minutes later. Although humpbacks are often cooperative during feeding, such interactions between calves appear to be very rare. Certainly, such uncommon happenings demonstrate the behavioral complexity of these animals, and lead us to imagine what other interactions and communications take place beyond our limited ability to witness them.
Whale positioned head down in the water column, an unusual behavior for humpbacks. © Jean-Francois Chabot
The inverted whale nose-to-nose with a female! © Jean-Francois Chabot
Finally, on the crossing back to Puerto Plata, we are granted a few more uncommon treats: passing pilot whales and a pod of spotted dolphins riding Explorer’s bow waves. Intriguing behaviors, calm seas and great visibility, plus a great deal of serendipity: another fantastic week on the Silver Bank!
Just 3 more weeks until this season with the whales on the Silver Bank is done! Just like the whales know they’ll return every year, so do we! 2015 is Aquatic Adventures’ 25th year providing guests the rare opportunity to observe these majestic mammals in their natural habitat during their mating and calving season. Join us for an adventure of a lifetime! For schedule and availability, click here.
Written by: Lisa LaPointe, Aquatic Adventures
Designed by: Heather Reser, Aquatic Adventures