 Humpback / Wikimedia / Whit Welles
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Whales
belong to the scientific order Cetacea, which is divided into two
groups: the Mysticetes
and the Odontocetes.
The Mysticetes, or baleen whales, are the majority of the whales that
we find in New England waters. These whales don’t have any
teeth!
Instead they
have baleen plates made up of keratin, the same material that makes up
our hair and fingernails. These plates hang down from their upper jaw
and allow the whales to filter their prey (usually planktonic animals
and small fish) from the seawater. This group consists of the blue
whale, fin whale, right whale, humpback, minke, and others. The
Odontocetes, or toothed whales, use teeth to seize and capture their
prey. Sperm whales, belugas and narwhals, all of the beaked whales, and
all of the dolphins and porpoises all belong to this group.
Whales are descended from land animals and are related to hippos. They entered the water 50 million years ago.
Baleen Whales
Humpback, Fin,
Minke, Right,
Sei
Toothed Whales
Atlantic White Sided
Dolphin, Long-Finned Pilot Whale,
Harbor Porpoise, Risso's Dolphin, Short-Beaked
Common Dolphin, Killer Whale
Baleen Whales
(Mysticetes)
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Humpback (Megaptera novaengliae)
Length:
35-50 ft. (Females larger than males)
Weight: 25-40 tons
Range: All major oceans
Humpback
whales are mid-sized baleen whales that frequent our area in the summer
months. They get their name “Humpback” from a small
hump on their back
located just in front of their small dorsal fin. These whales have a
black body with white flippers (pectoral fins). These flippers are the
longest of any whale, reaching up to 15 feet. This can be a third of
the whale’s body length! The underside of the flukes (tail)
vary in
color from all white to all black with everything in between. These
color patterns are unique to each whale, and allow scientists to
identify individuals and keep track of them. Humpbacks also have a
number of bumps on their heads, called tubercles, each containing one
hair. Scientists believe the whales use these hairs as a sensory
device. They have anywhere from 270-400 baleen plates on each side of
their mouth.
The humpbacks we see in our
area spend the winter months in the Caribbean, an area that serves as
their breeding and calving grounds. Humpbacks give birth in the middle
of winter to calves that weigh around a ton! These are big babies:
they’re born anywhere between 13-15ft. long! They can gain as
much as
100 pounds a day just by nursing on their mother’s milk!
After
traveling up from the Caribbean, humpbacks in our area stay in the Gulf
of Maine from late spring to early fall feeding. These whales are
feeding on krill (tiny shrimp-like animals) and small schooling fish
including herring, sand lance, and mackerel.
The favorite of many whale watchers, humpbacks are known for a variety
of behaviors, some of which appear to be playful. Rolling, flipper
slapping, tail lobbing, spy-hopping, and breaching are some examples of
these behaviors.
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Fin (Balaenoptera physalus)
Length:
Approx. 80 ft. (Females larger than males)
Weight: 60-85 tons
Range: All major oceans
Fin,
or finback, whales are the second largest animals to ever have lived on
earth! In fact, the only animal larger than a finback is a blue whale,
which can get up to 100 feet long! Finbacks are a very close second
though, reaching up to 80 ft. long, and sometimes a little longer.
These whales are dark gray on top from the tip of their mouth to their
tail, and are white underneath. They have a “V”
shaped chevron pattern,
lines of light gray, located behind the blowholes. These whales are
easily identified because the right side of their face is white while
the left is gray, known as asymmetrical pigmentation. In fact, even the
baleen in the front of the right side of the mouth is white! Scientists
believe this difference in color helps the whale feed. Finbacks have
between 260-480 baleen plates on each side of their mouth.
Although they are enormous animals, finbacks have a very sleek and
streamlined body that helps them swim very fast. In fact, they are the
fastest of the baleen whales, giving them the nickname
“greyhound of
the sea.” These whales can reach up to 30 miles per hour in
short
bursts!
Finbacks eat krill and small schooling fish including herring, capelin
and sand lance.
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Minke (Balaenoptera acutorostrata)
Length:
Approx. 30-35 ft. (Females larger than males)
Weight: Approx. 20,000lbs.
Range: All major oceans
Minke
whales are the smallest of the baleen whales found in our region. Their
body is dark gray on top and white underneath. They have a small,
curved dorsal fin and they have small pectoral fins. These flippers are
dark gray with a white band. When minke whales surface, they often come
up at an angle, which usually means that their spout gets lost in the
waves behind it. Minkes, therefore, get the nickname “little
piked
whale” because they often come up chin-first. Scientists find
these
whales difficult to study because they are frequently found alone, and
they are very quick. Often one will pop up once and then disappear.
However, they can be seen in small groups and in association with other
larger whales, usually in an area with an abundance of food.
For a long time these whales were considered too small to hunt, but as
the numbers of larger whales declined, whalers turned to these small
whales. In fact, these whales continue to be hunted today by Japan,
Norway, and Iceland.
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North Atlantic Right (Eubalaena
glacialis)
Length:
50-60 ft. (Females larger than males)
Weight: Approx. 200,000 lbs.
Range: Nova Scotia to Florida; southern
Iceland, and Norway to Spain
The
Right whale is a mid-sized baleen whale. They are mostly dark gray to
black with small amounts of white on the underside of their body. They
have small paddle-shaped flippers, a large head that is covered with
callosities (raised, rough patches of skin), a deeply notched tail, and
no dorsal fin. Their callosities are covered with whale lice, and each
right whale’s callosities form a unique pattern that allows
scientists
to identify individuals. They are easily recognized because they lack a
dorsal fin, but also because their spout forms a very distinct
“V”
shape. These whales are found off Cape Cod in winter and spring, the
Bay of Fundy in summer, and off Florida and Georgia (their calving
grounds) in winter. Right whales are different from the humpback,
finback, and minke because they are skim feeders and feed exclusively
on copepods (small planktonic animals). Instead of gulping like the
other whales, right whales feed at the surface with their mouths
partially open, filtering as they swim. Their baleen is much finer than
the other three previously mentioned whales, and is also much longer.
Minke whales have baleen that is about 8 inches long, humpbacks about
12 inches long, while right whales can have baleen that is 9 feet long!
Unfortunately, right whales are one of the
most endangered mammals in the world. Their population consists of
approximately 300 individuals. In fact, they got their name because
they were the “right” whales to hunt. These whales
are slow swimmers,
which made them easy to catch, they floated once killed, and they
produced a large amount of oil and baleen. Their baleen, called
whalebone by the whalers, was used for a variety of things including
umbrellas, women’s corsets, and buggy whips. Today these
animals are
federally protected because they still face many threats even though
they are no longer hunted. A large number of mortalities come from
ship-strikes and entanglements in fishing gear.
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Sei (Balaenoptera borealis)
Length:
50-65 ft.
Weight: 100,000 lbs.
Range: worldwide from tropical to sub polar
waters
Sei
whales are the third largest baleen whale. These whales are usually
dark gray on top and white on the belly. Their dorsal fins are tall and
curved. Sei whales look similar to finbacks, although both sides of the
face are dark gray (unlike finbacks which have different colors). They
have between 300-410 baleen plates on each side of their mouths, and
their baleen is very fine. Like the finback, sei whales have a very
sleek body, which allows them to swim very fast. Sei whales are known
for their unpredictable distribution, with a sudden arrival into an
area followed by an absence for years. Their migration still remains a
mystery to scientists. Likewise, very little is known about the social
behavior of these whales. They have a broad diet including copepods
(small planktonic animals), krill, squid, and small schooling fish. Sei
whales are the only baleen whales to feed both by skimming and gulping.
Although not a common visitor to our area, they have been seen the past
couple of years.
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Toothed Whales
(Odontocetes)
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Atlantic White Sided Dolphin
(Lagenorhynchus acutus)
Length:
8-9 ft. (Males larger than females)
Weight: 400-500 lbs. (Males weigh more than
females)
Range: North Atlantic temperate waters; from
mid-Atlantic states to Northern Europe
Atlantic White Sided Dolphins are the most common dolphin found in our
area, and are one of the most attractive of all cetaceans. These
dolphins are named for and are easily identified by their markings.
They are dark gray to black on their dorsal surface; the sides of the
body are light gray from head to tail; they have a white belly and a
white patch below the dorsal fin; they also have a well defined
yellowish-tan patch on both sides of the body above the white patch
that extends towards the tail. They have a short beak (rostrum), small
flippers, and a curved dorsal fin. Like most toothed whales, these
dolphins are highly social and can be found in groups (pods) anywhere
from 8 to hundreds of individuals. They are sometimes even found in
association with humpback and finback whales. These dolphins, sometimes
referred to as “lags” because of their scientific
name, eat a wide
variety of prey species including squid, herring, mackerel, hake, and
sand lance.
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Long-Finned Pilot Whale (Globicephala
melaena)
Length:
15-20 ft. (Males larger than females)
Weight: 2900-5000 lbs.
Range: North Atlantic and cool water in all
oceans in the Southern Hemisphere (circumpolar)
Pilot
whales are seasonal residents in our area. Their bodies are dark gray
to black with a light patch behind their dorsal fin, and a white patch
on their throat that resembles an anchor. They have a short beak, a
very round, or bulbous, head (called the melon), and a very thick,
curved dorsal fin. People often refer to pilot whales as
“potheads”
because of their bulbous head. They are usually found offshore
throughout most of the year, but come inshore following food and can be
seen in our area in late summer and early fall. These whales primarily
feed on squid and mackerel, but will also feed on a variety of small
fish. They are usually seen in small groups (pods) of 10-20
individuals, but can be found in much larger groups.
Unfortunately, pilot whales are often known for their tendency to have
mass strandings, including here on Cape Cod. Scientists continue to
study these incidents to try and learn what might cause these animals
to strand. Could it be a result of navigational difficulty, prey
chasing, disease, or predator avoidance? Most likely it is a
combination of these, but the answer is still unknown.
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Harbor Porpoise (Phocoena phocoena)
Length:
Approx. 5 ft. (Females are slightly larger than males)
Weight: 134-168 lbs. (Females weigh more than
males)
Range: cool temperate waters in both the North
Atlantic and North Pacific oceans; primarily coastal
The
harbor porpoise has a robust body. It is dark gray to black on its
back, with lighter gray sides and a white belly. They have a short beak
(rostrum) with spade-shaped teeth. Their dorsal fin is triangular, and
located at the center of its back. These animals can be found by
themselves or in small groups. They surface quickly when they breathe,
and their exhalations can be heard clearly very often. For this reason
some fishermen in Canada and New England refer to the porpoises as
“puffing pigs” or “puffers.”
Unlike their dolphin cousins, the harbor
porpoise is not known for its acrobatics. Their diet consists mostly of
small schooling fish such as herring, mackerel, sand lance, hake, and
capelin, however, they will also eat squid. In the Gulf of Maine,
calves are born usually in May.
Harbor
porpoises have a history of being susceptible to entanglements in
fishing gear, especially gill nets. Efforts have been made to try to
reduce the number of these incidents. Sounding devices or
“pingers”
have been placed on the nets to deter the porpoises.
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Risso’s Dolphin (Grampus
griseus)
Length:
12-13 ft. (Males are slightly larger than females)
Weight: Unavailable
Range: All major oceans, tending to be in
tropical and temperate waters
Risso’s
Dolphins are not a common visitor to Stellwagen Bank because they are
typically found further offshore; however, they can be seen in our area
on occasion. These dolphins progressively change color from dark gray
to light, as they become adults. They somewhat resemble pilot whales
because they have a very short beak and a rounded head (though not as
bulbous as a pilot whale). Risso’s Dolphins also have a
curved dorsal
fin (taller than a pilot whale), and small paddle shaped flippers.
Often referred to as “grampus” because of their
scientific name, they
are known for scars and scratches that mark their bodies, most of which
come from other Risso’s Dolphins. These dolphins are usually
found in
groups of 12-25 individuals, sometimes more. Squid makes up the
overwhelming majority of their diet. When these dolphins are seen in
our area, it is likely a result of them coming inshore following squid.
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Short-beaked Common Dolphin
(Delphinus delphis)
Length:
8-9 ft. (Males larger than females)
Weight: Approx. 330 lbs.
Range: tropical and warm temperate waters of
the Atlantic and Pacific Oceans
Another
species that is not often found over Stellwagen Bank, the Common
Dolphin is generally found further offshore. These dolphins have a
medium sized beak (larger than Atlantic White Sided Dolphins), a tall,
curved dorsal fin, and medium sized flippers. Their bodies are white
underneath and dark gray to black across the length of the back,
including the tail. They have a tan patch on both sides that runs from
the eye to the middle of the dorsal fin; and they have a light gray
wash across their backs that meets the tan patch on both sides. This
creates an “hourglass” shape on both sides of the
body, which makes
identifying this species relatively easy. These dolphins are usually
found in groups of about 30 individuals or less, but can be found in
hundreds and sometimes thousands! Like other toothed whales in our
area, Common Dolphins rely on squid and small schooling fish for food.
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Killer Whale (Orcinus orca)
Length:
25-30 ft. (Males larger than females)
Weight: 8,400-12,000 lbs.
Range: All major oceans
Killer
whales are one of the most recognized of all the whales, however, they
are not often seen over Stellwagen Bank. These animals are often found
further offshore, and the last confirmed sighting on Stellwagen Bank
was in 1986. Killer whales, often referred to as
“Orcas,” are, in fact,
the largest member of the dolphin family. They have a very robust body,
large rounded flippers, and a small beak. Their bodies are mostly
black, with a white belly, white patches behind the eyes, and a light
gray to white patch behind the dorsal fin. A male’s dorsal
fin is tall
and triangular, and can reach up to 6 feet tall! A female’s
dorsal fin
is much shorter and curved. Killer whales have 10-14 pairs of large
teeth, which they use to eat a wide variety of prey. These whales have
been known to feed on small schooling fish, squid, seals, and even
large baleen whales and sperm whales.
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