Whales You May See
Humpbacks
One of the whales you're likely to spot during a Boston Harbor Cruises Whale Watch is the humpback. These Northern hemisphere whales reach an average length of 50 feet, and weigh about 37 tons! Sadly, they're also among the most endangered. It is estimated only 8 percent of their original population remains.
The humpback got its name because of the way its back arches out of the water when getting ready to take a deep dive. "Megaptera" is its true scientific name, which means "large-winged," in reference to its long flippers. Each humpback has distinct black and white markings on its fluke (tail). Since no two flukes are alike, scientists use these markings to distinguish one humpback from another.
When humpbacks leap up into sight, it’s not because they like putting on a show. They’re actually "lunge feeding" - plowing through heavy areas of food with their mouths open wide, ready for the catch. While you're taking pictures, they're dining on schools of fish like anchovies, cod and capelin.
Humpbacks are also famous for their "singing." These mammals can put Pavarotti to shame: they're capable of hitting octaves that include frequencies humans can't pick up. Male humpbacks are the divas, with songs lasting as long as half an hour - and then repeated with slight changes. While singing, the whale floats essentially motionless, head down in the water. The purpose of the song is believed to be mating or possible male dominance/ aggression behavior. Scientists also believe humpbacks communicate by slapping the water with their fins and tail flukes, which creates noise other whales can hear far away under water.
Minkes
Minkes are some of the most abundant whales in the world today. They are sleek, small, dolphin-like baleen whales. Because of their relatively small size, and lowered energetic needs, their diet is a wider variety of fish than the larger fin and humpback whales. At times, they may even take single larger fish rather than large quantities of smaller fish.
Very little is known of the life history of Minke whales. Females are thought to give birth to one calf at a time once every 1-2 years. Mother-calf pairs are rarely observed, although in the past several years we have started to see what we think are independent calves (based on their size) with a probable mother staying in the general vicinity, but not with the youngster, during September and October on Stellwagen Bank.
Finbacks
Finback whales, at 45-70 feet long and weighing 40 tons, are second in size only to blue whales. Their most distinctive characteristics include an asymmetrical lower jaw that’s white on the right side and grey-black on the left with 50-200 pleats on the lower jaw that expand during feeding.
Finbacks are primarily seen as solitary animals, although coordinated groups of up to 15 animals together have been observed. Mating is thought to take place during the winter, although several observations of apparent mating activity have taken place during late summer off the Maine coast.
There is some evidence finbacks may live up to 100 years, although confirmation depends on more accurate aging techniques. Fortunately, now that this endangered species is protected worldwide, their numbers (60,000-100,000) will hopefully grow and more will get the opportunity to live out their long lives.
White-Sided Dolphins
Atlantic white-sided dolphins are found only in the North Atlantic, generally from waters just south of New England north to Norway. They’re frequently sighted in groups as small as 10-15 animals, and as large as several thousand together. Groups of 100 or more are generally called 'superpods' and are believed to be temporary associations that may form for foraging, cooperative feeding, or just travel. We’ve typically seen group size increase through our field season, and most superpod sightings occur in August through October.
The diet of these dolphins consists of a combination of squid and fish such as herring. Atlantic white-sided dolphins, like all dolphins, feed on single prey items, so they are less likely to feed on the large numbers of small fish that whales usually do.
For more whale info, visit these sites:
whalecenter.org: The Whale Center of New England
whale.net: Interactive Educational Website
stellwagen.noaa.gov: Stellwagen Bank Information