- Research & Education
- Cape Cod
October 13th was a beautiful crisp, clear, fall day, and once we arrived at the southern area of Stellwagen Bank National Marine Sanctuary, about six miles north of Race Point in Provincetown, it seemed as though there were humpback mother and calf pairs everywhere we went!
The highlight of the morning’s trip was certainly Anchor’s calf who surprised everybody on board the Dolphin VIII by breaching, or jumping out of the water. By the afternoon, more animals had moved into the area, including Reflection, her calf, as well as a third animal. When an adult humpback travels with a mother and calf pair, it is known as an “escort.” Sometimes this escort animal stays with the pair for a few hours, and sometimes the association lasts for several days. That escort animal can be male or female, and scientists do not yet know how these whales choose these associations.
Reflection and her calf with escort
Sometimes adult animals travel together, even in the absence of a calf, and this was the case for the humpbacks we encountered after leaving Reflection and her calf. Apex, a female born in 1982, was traveling with Echo, another mature female, born in 1988. As we watched Echo and Apex traveling linearly, we were captivated by Filament and her calf. Filament’s calf approached the boat and rolled on its back underneath the bow.
Filament’s 2007 calf
As Filament’s calf rolled and dove, we could predict its re-emergence simply by watching for the green glow in the water. Because of all of the microscopic phytoplankton in the water, anything white in the water will look green as it reflects the color of these microscopic organisms. Phytoplankton, like all green plants, has chlorophyll, a pigment which absorbs the sun’s energy to convert it to food energy. The density of phytoplankton in Stellwagen Bank reflects the high nutrient load circulated by the cold, rich currents of the North Atlantic.
Green glow from below
On October 14th, the abundance of mother and calves continued, and we started the day with Isthmus and her calf, as well as Reflection and her calf—this time without the escort. A group of six humpbacks observed together during the morning’s trip included Apex, Peninsula, Perseid and her calf, as well as Hancock and her calf. Considering the group arrangement of many of these humpbacks on yesterday’s trip, it’s no wonder that scientists have a hard time deciphering the meaning of associations among humpbacks!
Both Perseid and Hancock are here this summer with their first calves. Perseid is nine years old and Hancock is sixteen, neither of which is a particularly unusual age for a humpback to have its first successful mating. Hancock’s calf has extremely white flukes, and at about nine years old, it’s sometimes difficult to tell that this animal is still a calf!
Hancock’s 2007 calf
October 15th was a bright and windy day, and on our morning trip, we came across a twenty-one year old female named Lichen. Lichens are the result of a symbiotic relationship between a fungus and algae or cyanobacteria, and the patchy markings on this whale’s fluke or tail is reminiscent of this resultant symbiotic organism frequently found on rocks and trees.
Our afternoon trip brought us the slew of humpbacks typical for the week, as well as a small pod of Atlantic white-sided dolphins. Between twenty and forty of these small toothed whales swam beneath the bow of the Dolphin VIII as a group of six humpback whales fluked and dove nearby. Although Apex and Peninsula had left Perseid, Hancock, and their respective calves, the two new moms were accompanied by Falcon, first seen in 1998, as well as Mostaza, who is one of Salt’s calves, born in 2000.
On October 16th we were not able to get out to see the whales due to rough seas and limited visibility, but by October 17th we were back in business and it was an ideal day for whale watching! The seas were glassy calm, so we could easily see a group of four humpback whales logging from quite a distance. A humpback is said to be “logging” when it floats at the surface, moving very little or not at all, and is thought to be in a resting state.
At a bit of a distance from the logging group was a fifth animal, later identified as Hancock’s calf. Hancock’s calf would intermittently split from, and then rejoin the group. Instead of resting, this young whale seemed to be much more interested in playing with the clumps of seaweed floating in the water.
Hancock’s calf plays with seaweed
On October 18th the clear weather we had enjoyed on previous days was a memory. Despite the fog, we decided to head out to the location where the whales had been spotted yesterday to see if we could relocate them. Because there is no special “whale detection equipment” on board these whale watch boats foggy days can be challenging. When visibility is limited, we sometimes rely on our ears as much as our eyes in order to find whales.
Once we got to the southeastern portion of the Stellwagen Bank National Marine Sanctuary, we stopped the boat in several different places to listen for the loud exhalations, or spouts, of the humpbacks that had been frequenting the area in previous days. Finally, almost two hours into the trip, we heard the unmistakable sigh-like sound of a humpback whale, as Hancock’s calf appeared next to the boat.
Humpback in the fog
Soon, four other humpbacks burst to the surface. Fortunately for us, these humpbacks were very curious about us. As the three adult humpbacks, Hancock, Perseid, and Milkweed, dove and surfaced intermittently, the two calves, belonging to Hancock and Perseid, appeared on either side of the Dolphin VIII, rolling around on their backs and sometimes even spyhopping, or lifting their heads right out of the water!
Upside down in the fog
On October 19th the group of five humpbacks seen on the previous day had remained in tact, and the scientist and crew aboard the Dolphin VIII wondered whether or not the humpbacks were feeding below the surface. Milkweed, Hancock, and Perseid surfaced with great speed, water draining out the sides of their mouths. Humpback whales belong to a group of baleen whales known as the “rorquals.” The rorqual whales are characterized by folds of skin running down the ventral side of their bodies. When these whales take in a mouthful of food, these pleats or folds expand to accommodate over one thousand gallons of food and water. When these whales surface with these pleats partially expanded, it suggests that these whales are feeding.
Although these whales will be heading south within the next few months, they are still very active here in the North Atlantic, feeding, as well as caring for their calves, who are preparing to go off on their own. We ended our day with one of this year’s unnamed humpbacks breaching and flipper slapping, much to the delight of passengers on the Dolphin VIII!