- Research & Education
- Cape Cod
The most common of the toothed whales sighted in our waters is the Atlantic White-Sided Dolphin. It is about moderate size for a dolphin, 7 to 9 feet long and weighing 400 to 450 pounds. It is built very much like a bottlenose, but not as robust. And the beak (rostrum) is shorter and thicker than that of the bottlenose. Dark on top and white underneath (as is common with dolphins) the flanks are uniquely colored. The gray band is brokem beneath the dorsal by a white patch that borders a yellowish-tan streak that extends nearly to the tailstalk. There is a dark patch around the eye.
In the nearshore waters close by, they feed on squid, herring, sand eels, and mackerel, and are often seen cooperatively herding fish near the surface. Group sizes range from just a few to several hundred and it is a common occurence for many small groups to merge for socializing, hunting, or migrating. These larger groups appear to have a great deal of cohesion.
Mating occurs all year long (just like in humans), but the peak birthing months are June and July. Gestation takes 11 months and nursing lasts about 18. Young animals appear to spend time in small groups of their own, in much the same way, I suspect, as we would like isolate our teenagers.
These animals spend time inshore and time offshore. It is when they are close that we sight them from the whalewatches. Offshore activity may be quite different. Inshore, group size reported by naturalists usually ranges from 35 to 75. They appear to be curious about vessels and will bowride if the boat is going in the way they are heading. They are frequently seen surfing in the wakes of boats and are know to leap as a wake crosses their path.
Again, this week, the sightings of minke whales and even large numbers of finback whales (8 on July 05, 6 on July 7, 11 on July 8, 12 on July 10, and 8 on July 11), in the public eye, were no match for the sightings of humpback whales enjoyed by the passengers of the Dolphin Fleet.
In reading over the reports of this week’s sightings, it is clear that the beginning of the week was, very plainly, about Spoon and her calf. Reports of this pair fell into to categories: nursing and curiousity. I have already commented on the large size of Spoon’s calf. It has already mastered the art of nursing (and if you think that nursing without flexible lips is easy, try creating suction with your elbow). As it turns out, and to the best of our understanding, nursing among whales is a bit different than nursing among cats or dogs. In whales, the calf does not directly suckle. What appears to happen is that the calf nudges up against the mother’s mammary gland. The strong muscles surrounding the gland contract, forcing the milk out of the mammary slits and into the water. It is thought that, early on, the calf might roll its tongue into a straw for drinking and as it starts to be weaned, uses its baleen to collect the rich milk from the water. This would explain why whale milk is as much as 35 to 50 percent milkfat whereas the milk we get at the grocer is only 4 percent milkfat (if we even buy whole milk).
Nearly half of the sightings of this mother and calf pair this week make note of nursing behavior. The other half of the sightings speak of curious behavior. The calf, or the mother, or even both, becoming interested in checking out the boat that is checking them out. It should be pointed out that it is not about whales interacting with us, it is about whales interacting with the boat. Boats are large, dark objects that float on the surface. Incidentally, they are just as curious about oil cans, seaweeds, icebergs, and even pizza boxes. That doesn’t, and shouldn’t, change the perspective of the passengers. The whale might be interacting with the boat, but the passengers are interacting with the whale. As an educator, this is very important to understand. Despite the fact that we are both mammals, we are quite different. When the passengers interact with the whale it gives them an opportunity to connect with it, sparking their interest. As a conservationist, it is more important. For we protect the things that we love and we love the things that move us and the things that move us are the things that we can see and feel and be touched by. As a passenger, if you should be lucky enough to have a whale approach you boat with curiousity, remember that what you get out of that encounter is, in the long run, of greater benefit to that whale than what it got. You might have been inspired to learn about them. Or you might have been inspired to protect the whales and their habitat.
Toward the end of the week, larger numbers of humpback whales moved closer to Provincetown. Back again to making their living here.
Somewhat of an exception was the sighting of Cardhu and her calf on July 11. The calf began tailbreaching and then flipperslapping beside its mother. Slowly, the flipperslapping moved across its mother’s back. After just a few slaps, the calf began nursing. It looked, to this naturalist, that the calf was saying, “I am hungry.”