June 2nd’s afternoon trip experienced a wide variety of humpback whale behaviors.  Buzzard, one of our humpbacks, was observed actively feeding, kickfeeding and blowing bubble nets.  Meanwhile, other humpbacks in the area rested at the water’s surface, only slightly moving every few minutes to take a breath.  Because whales are voluntary breathers, they’re not able to sleep in the same way other mammals would.  In becoming unconscious, they would forget to breathe!  Although dolphins in captivity have been known to sleep with half of their brains at a time to overcome this obstacle, scientists are not sure whether or not this is the case with large whales in the wild.  The resting behavior of humpbacks and other large whales is called logging, as the sedentary bodies of a large whale resembles a log floating on the surface of the water.

 

 

Humpback whales logging

 

The dense fog and limited visibility made June 3rd’s whale watch a little bit more challenging for our captain and crew.  Sometimes, just listening for the loud exhalation of a whale can be the best way to find whales in pea soup-like fog, and today, the sharp listening skills of our passengers and crew paid off.   Pressurizing the air in their lungs is one of the ways whales conserve their oxygen, so when that pressure is released during an exhalation, the resulting noise is unmistakable.  Using our ears and our limited visibility, we finally located our first humpback on the Southwest corner of Stellwagen Bank. 

 

Sometimes the most memorable whale watches occur on days with less than ideal weather, and certainly, today was one of these days.  As soon as we found Circus, a young humpback whale, it became incredibly active, displaying some of the most dramatic humpback whale surface behaviors, including flipper slapping, lobtailing, and even full spinning head breaches.  Circus was named for the marks on the underside of its fluke, which resemble the attractions of a three ring circus, including a shape that looks like someone being shot from a cannon!  Certainly with this acrobatic behavior, Circus was living up to its name. 

 

 

Circus lobtailing

 

After canceling June 4th’s trips due to high winds and rough seas, we weren’t sure what to expect for June 5th’s trip.  Our whalewatch vessels visit such dynamic ecosystems that they can drastically change over the course of a day.  The most dramatic change that we noticed was the return of the greater shearwaters.  Greater shearwaters are gull-sized birds which spend most of their lives at sea.  Like our humpback whale population, greater shearwaters summer in the North Atlantic to take advantage of the highly productive ecosystem and abundant food.  We often find them in the same locations as our humpbacks because they both especially like to feed on sand lance. 

 

Greater shearwaters, however, travel an even greater distance than our humpbacks during their migrations.  Greater shearwaters are transequatorial migrants, which mean that they traverse the equator over the course of their winter travels.  During our winter season, greater shearwaters nest and breed on the rocky islands off the coast of Argentina.  This is the only time that they spend on land.  The return of the greater shearwaters are a sign that summer is here at last. 

 

June 6th brought typical Cape Cod weather, which seemed to change every hour.  The morning trip experienced six foot swells and overcast and rainy weather.  By the evening trip, the sun had emerged and the seas had calmed to a flat, glassy plane where spouts could be heard and dorsal fins could be seen emerging from the water from many miles away. 

 

After finding three different species of baleen whale during the morning trip, Captain Steve Milliken noticed something strange in the water.  “Could that be a basking shark?” he wondered.  Basking sharks usually are not found until later in the summer when the water temperature is a bit higher, however, this particular animal was early-season surprise for us. 

 

 

Basking Shark

 

Basking sharks have a menacing appearance, reaching lengths of over thirty feet, but they are not a threat to humans.  Basking sharks have a filter-feeding apparatus in their mouths which is not unlike the baleen in a whale’s mouth, which they use to filter and consume zooplankton.  Like the right whale, the basking shark acquires most of its nutrients from copepods, and sure enough, when we performed a plankton tow near the feeding shark, the water was thick with these orange, shrimp-like crustaceans.  The similarity between the sharks’ filter feeding apparatus and the whale’s baleen is an example of convergent evolution, which refers to instances in which very unrelated species acquire similar anatomical structures to deal with similar environmental conditions.  Other examples of convergent evolution in nature include bird and bat wings, and the webbed feet of various aquatic animals.

 

 

Passengers observe a basking shark from the Dolphin VIII

 

 

 

June 7th- After several days of relatively quiet behavior, our humpbacks began the day with a feeding frenzy.  At least 27 humpbacks, including Weave, Percussion, Tracer, Grommet, Grackle, Nimbus, and Ember were blowing bubble nets to corral fish, and swallowing hundreds of sand lance with every expansive mouthful.  Humpback whales are opportunistic feeders, and are not known to favor one time of day over another for feeding.  For that reason, we are always grateful to be able to find them as they perform their dramatic feeding behaviors. 

 

 

 

Humpback whales blow bubble nets while feeding

 

By the evening’s trip, the feeding had ended, but the excitement continued as a humpback whale named Ventisca curiously approached the Dolphin VIII, even lifting its head out of the water to try to see us more clearly!  Ventisca is the Spanish word for blizzard, which describes the unusual white pigmentation on its dorsal fin. 

 

 

Ventisca's white dorsal fin

 

 

Ventisca sneaks a peek at Dolphin Fleet whale watch passengers

 

On June 8th we came across a smaller humpback whale that appeared to be a juvenile.  As adults, humpbacks can reach lengths of almost 60 feet, but it can take them 8-10 years to reach full maturity.  As they get larger and acquire more blubber, they fluke with more and more consistency; however, younger whales sometimes fail to display their flukes as they dive, making them more difficult to identify as individuals.  One activity on the Dolphin Fleet is the “Blubber Glove” experiment, where passengers can experience the insulating power of whale blubber, using cooking fat as a substitute for the real substance, of course.

 

 

The “Blubber Glove” experiment

 

Later, we came across one of our most easily-identifiable individuals.  A female humpback named Nile with her third calf.  Although they were logging, or resting at the surface without diving, we immediately knew it was Nile due to her distinct, hook-shaped dorsal fin. 

 

In the afternoon we had another encounter with a juvenile humpback, and this one seemed just as interested in us as we were of it.  As the Dolphin VIII drifted with Highland Lighthouse in Truro looming in the background, our humpback whale approached the boat, lifted its head to look at us, and swam back and forth underneath the boat, possibly investigating the sound of our generator.  Meanwhile, a harbor seal appeared next to the boat to get a closer look at us as well.  This close encounter with several of the planet’s most fascinating creatures marked an end to another fantastic week of whale watching. 

 

 

Harbor Seal