Blue Whales of Baja
and photos by Michelle Gilders
Is a child, I witnessed my first whale ever
– a blue whale. Admittedly it wasn't
a real one, but the memory of it will be imprinted
in my mind forever. This "counterfeit"
blue whale was suspended from the ceiling of
the British Museum of Natural History –
a mighty blue mass of plastic and fiberglass.
It was a lifeless, static embodiment of leviathan;
but, it was enough to enthrall me. To really
appreciate the whale though, one must venture
beyond the dusty halls of museums and view the
animal in its three dimensional liquid habitat:
flowing, flying, in an all embracing, all supporting
first saw blue whales off the southwestern coast
of Baja California in 1989 and have been fortunate
enough to see them every year since. It was
also my first trip to the peninsula. It was
a memorable trip for many reasons, but seeing
blue whales was perhaps the most astounding.
There is such mystery surrounding these animals
and they are now such a rarity, that it was
hard to imagine, back in England, translating
that hope into reality.
Blue whales are found in all of the world's
oceans. They are immense animals by anyone's
standards. Their scientific name, Balaenoptera
musculus, is a name that is certainly suggestive
of their size and strength. They can reach more
than one hundred feet (33 meters) in length
and weigh 180 tons (190,000 kg), the largest
of all animals found in the Southern Hemisphere.
whales have arteries so large that a small child
could crawl through them. At birth they are
22 feet long (7.5 meters) and weigh 3.5 tons
(3,500 kg). The blue whale calf gains about
200 pounds (90 kg) a day on its mother's
fat and protein-rich milk, and will weigh 16.5
tons (17,000 kg) when it is weaned 7 or 8 months
All whales fall in the mammalian Order Cetacea.
There are eighty recognized species of cetaceans
and the waters of Baja are home to roughly one-fifth
of those. Cetaceans are classified into two
broad suborders: odontocetes and mysticetes,
also referred to as toothed and baleen whales.
Baleen is a fibrous material similar to keratin,
of which fingernails are made. The baleen is
arranged in plates along the upper jaw of mysticetes,
such as the blue whale, with the bristle-like
fibers projecting along the inside of the mouth.
Unlike toothed whales, such as dolphins and
sperm whales, the skulls of baleen whales are
symmetrical; this is related to the fact that
baleen whales do not use echolocation.
are air breathing, fully aquatic mammals. Blue
whales have a double blowhole, as do all baleen
whales, while toothed whales have a single blowhole.
Having a nose on top of the head is an ideal
adaptation for marine animals, but it is one
that took millions of years to evolve. All cetaceans
also have a torpedo-like body shape, their front
limbs modified to pectoral flippers (an elongated
paddle-shape in the blue whale). They do not
have any visible hind limbs; and, most species
have a dorsal fin.
tail flukes of whales and dolphins are horizontal,
unlike the tails of fish, such as sharks, which
do not have external ears or ear muscles and
they do not have scales or gills. All mammals
have hair, but in whales it is often hard to
see. Whales lack a covering of fur, but many
baleen whales have sensitive hairs on their
rostrums or snouts, and embryonic cetaceans
show a covering of hair that disappears as the
fetus develops. Cetaceans do not have sweat
or sebaceous glands; instead, they have a thick
layer of blubber, fat and oil beneath their
skin that is used for insulation, heat regulation
and energy storage.
It is hard to mistake a blue whale for anything
else when seen from a boat. At the surface,
the animal is slate or slightly grayish blue,
with a mottling pattern on its back. In the
moments before it surfaces, sending its blow
25 feet (8 meters) into the air – the
tallest blow of any whale – it turns the
whales will often dive for 10-20 minutes at
a time, although longer dives are certainly
known. They will usually follow dives of that
length with 8-15 blows at the surface. When
blue whales fluke, the tail stock is dramatically
thick and visibly powerful. As with other whales,
blues will often repeat the surface, dive, and
respiration patterns they establish. Under normal
circumstances they swim at speeds of about 22
km/hr (13.5 mph), but can sustain speeds of
48 km/hr (30 mph) if frightened or chased. This
is truly remarkable considering that we usually
equate size with sloth rather than speed.
dorsal fin on a blue whale is small relative
to its body size. It is usually about 13 inches
(33 cm) tall and tends to have a swept-back
appearance. The fin is not as tall, sharp, or
as obvious as that on other rorquals and at
times it may look more like a bump than a true
fin. The dorsal fin is a long way back on the
animal's body, only appearing shortly
before it dives. If you witness a blue whale
lunge-feeding you will also see the numerous
ventral grooves on its throat. These white pleats
are very distinctive and have an almost rubber-like
appearance. In the past, blue whales were called
"sulphur bottom" whales, a term that
referred to the sometimes yellow-coating of
diatoms that take hold on their undersides and
along their ventral grooves.
whales are in the same family and genus as minke,
Bryde's (pronounced Broo-dus), sei and
fin whales. They are collectively known as rorquals.
Rorqual is a Norwegian term that means "furrow
whale" and refers to the numerous throat
grooves that identify whales in this family.
It is these grooves that allow the rorqual to
expand its throat and take in more food and
water as it feeds, typically on krill or small
fish. Humpback whales have 10-36 throat grooves,
while the blue whale may have as many as ninety-four.
other rorquals feed on fish, the blue whales'
diet is almost exclusively krill. Krill are
shrimp-like crustaceans, called euphausiids,
typically less than 2 inches (5 cm.) in length.
Krill often swarm in huge clouds in the upper
water column and can be seen where currents
meet, traveling where the water takes them,
but also moving up and down in the water column
on a diurnal cycle. Since blue whales may feed
on 40 million individual krill each day, their
feeding strategy has to be specific. It would
be energetically inefficient if blue whales
fed on small numbers of krill, so they concentrate
only on the large groups.
whales usually feed at depths of less than 300
feet (100 meters), and sometimes, when the krill
is concentrated near the surface, they will
lunge upwards, scooping up krill and water and
revealing the black baleen in their cavernous
mouths in a spectacular display of mass and
power. Blue whales take full advantage of gravity
when they lunge-feed, opening their mouths wide
while they take in as much water and krill as
possible, often tripling their mass. They then
roll over onto their sides or back, allowing
the weight of the water to push down against
their baleen. In this way, the water streams
through the baleen under its own force and the
whale is left only to wipe the krill off the
inside bristles with its tongue. Each blue whale
has between 300-400 baleen plates attached to
the upper part of its mouth, ranging in length
from 20-40 inches (50-100 cm) each.
(except humpback whales, which are somewhat
unique) tend to be streamlined and they have
broad, flat rostrums, sickle-shaped dorsal fins
and short pectoral flippers. Blue, fin, sei,
Bryde's and minke whales appear very similar,
just in descending order of size. Of these rorquals,
only the blue whale lifts its tail fluke out
of the water on its dives, and then only infrequently.
It is estimated that only 10-15 percent of the
blue whale population flukes while diving. The
streamlined rorquals simply do not need the
extra impetus that this motion gives them, and
fluking blue whales could be viewed as genetic
relics of a time when all rorquals fluked. Blue
whales are fast swimmers and do not support
the colonies of barnacles on their flanks or
throats that can be seen on gray or humpback
whales, although the trailing edge of their
flukes may carry some of these freeloaders.
was the size of rorquals like the blue and fin
whales that attracted commercial whalers. These
large mammals are known for their rapid swimming
speed, and this ability protected them from
whaling until the advent of steamships.
the single season of 1930-31, 29,410 blue whales
were killed in Antarctic waters. This unsustainable
take fell dramatically in subsequent years,
with 12,559 taken in 1939-40, and 6,313 in 1949-50.
In total, 328,177 blue whales were killed in
the Antarctic between 1909 to 1965. In the early
1960s, the International Whaling Commission
began various measures to protect the whales,
but non- compliance from a number of whaling
nations effectively negated that protection.
It was only in 1966, when the animal was believed
to be commercially and possibly even biologically
extinct, that a complete cessation of whaling
Blue whales have been elusive animals to study.
The pre-whaling population of 220,000 to 240,000
individuals has been reduced to probably less
than 12,500 and recovery is proceeding at a
painfully slow rate. Truthfully, no one knows
how many blue whales are left. Whales are difficult
and expensive to count, and those species for
which we have sound population data tend to
be coastal for at least part of the year.
commercial whaling, the majority of blue whales,
perhaps as many as 90 percent, lived in the
Southern Hemisphere. Today the healthiest population
of blues is in the North Pacific (which includes
the Baja population). Some estimates put this
population as high as 2,500. Blue whales spend
the winter in temperate and tropical waters,
probably mating and giving birth to their young
during that time. Female blue whales give birth
to a single calf every 2-3 years, after carrying
that calf for 10-12 months. There have been
records of twins from the decks of whaling vessels,
but it is very unlikely that a blue whale could
bring two fetuses successfully to term.
groups of blue whales may be seen together,
researchers do not know how permanent, if at
all, these groupings are. The core of blue whale
"society" is the cow and calf. All
other groups of blue whales are believed to
simply reflect animals coming together using
the same, localized resource.
whales migrate to high latitudes during the
summer, feeding in the rich, cold waters. In
the Southern Hemisphere blue whales venture
farther south into Antarctic waters than the
other rorquals, while in the Northern Hemisphere
they tend to concentrate in the North Pacific
(into the Gulf of Alaska and the Bering Sea)
and the North Atlantic. Each population is believed
to be divided into distinct genetic stocks that
do not intermix on a frequent basis; this is
one of the reasons why stock recovery is believed
to be taking so long.
Most baleen whales feed primarily on their summering
grounds; however, blue whales are known to feed
all year round. This year-round feeding is probably
dictated by their large size – they simply
cannot sustain themselves by feeding for only
half the year.
data has given us a great deal of information
on size, weight and reproduction of this magnificent
animal. It is very difficult to age baleen whales,
however, since they lack the teeth that can
be so conveniently sectioned in toothed whale
species. Whaling records and estimates based
on morphological features, (especially sectioning
the wax plugs that collect in the ear canal),
suggest that some blues can reach ages of 110
years old, similar to the upper age range of
several other cetacean species.
is so much that we have yet to learn. We know
little about whale migration routes, where their
calves are born, their mating, social structure
and communication. And these are things that
cannot be learned by wastefully killing whales.
researchers are able to study individual blue
whales, something that is essential if we are
to begin to unravel the more intimate and social
aspects of their lives without resorting to
destructive harvesting. Individual whales are
identified by the distinctive mottling patterns
around their small, sickle-shaped dorsal fins.
These markings are not as easy to see as the
well-known humpback whale fluke patterns, but
are going a long way in helping researchers
develop a database of animals that can be used
to determine migration routes and group associations.
have also recently begun putting radio-tags
and satellite transmitters on blue whales off
the northern California coast, in hope that
the data collected will tell them more about
blue whale distribution and behavior. This is
a time consuming and expensive approach, but
even a small sample of tagged animals will provide
valuable data. Other research involves looking
at genetics by collecting small samples of tissue
using cross-bow bolts shot at the back of a
retreating whale. The bolts do not cause any
permanent damage to the whale, but do enable
researchers to collect enough tissue to run
DNA tests and perhaps help to establish family-trees
for discrete populations.
of the most remarkable discoveries to emerge
about blue whales is that they use very low
frequency sounds, 20-60 Hz, with high source
levels of more than 188 dB (equivalent to an
airliner taking off). This is the most powerful
natural sound produced in the animal kingdom.
Little is known about how, or why, the whales
use these sounds. They may use low frequency
sounds, and some higher frequency clicks to
locate krill, but they do not have an echolocation
system that is anywhere near the sophistication
of sperm whales or dolphins.
Some have postulated that before the oceans
became the noisy places they are today, filled
with tankers, boats and submarines, blue whales
could be heard around the world. It is intriguing
to speculate that they may use sound to map
their migration routes, or keep in contact with
animals oceans away. The U.S. Navy is using
these same low frequencies to map large portions
of the seabed. As we learn more of the blue
whales' ability to project low frequency
sound over vast distances, we may have to rethink
our view of these great whales as relatively
will never forget the first time I saw a blue
whale. It was a magical experience multiplied
seven times and cradled in the warm, calm waters
of the Pacific:
that first experience, I have watched bottlenose
dolphins bow-ride off the snouts of blue whales
and a 35-foot, four-month old juvenile play
around our boat while its mother dozed at the
surface 300 feet away. Every blue whale I have
seen has been memorable, even those half hidden
in fog have emitted a powerful presence. The
blue whale is the pinnacle of the whale-watching
experience. With few blue whales remaining,
the chance to see one is made all the more special,
tinged perhaps with an element of sorrow.
Whale-watching requires a great deal of patience
and a good eye. When you are on the water, look
for anything that stands out as unusual or different
– a flash of sunlight on the flank of
an animal as it surfaces, a group of birds on
the water, a distant blow, a splash or wave
that doesn't quite fit in with surrounding
the animals slowly. Don't make any sudden
gear shifts as reversing gears often startles
whales. Head towards the whales at an angle,
not from directly behind or in front. Never
pursue whales. You want to record naturally
occurring behavior, not pursuit.
the whales' behavior carefully. They often
demonstrate a regularity in their actions. If
a whale surfaces and blows 8-10 times and then
dives for ten minutes, it will often repeat
this routine. Watch for the flukeprint (the
calm, circular slick of water that results from
the down thrust of the whale's flukes);
it often appears on the surface after a dive,
or when the whale is swimming just beneath the
surface. By gauging how fast the animal is swimming
you can guess where it will surface. In blue
whales, the sight of the small dorsal fin, often
with a slight hunching of the back, is an indication
of a dive and possibly that the animal will
whales, like most marine mammals, can be elusive,
and sometimes appear with little warning. You
can maximize your chance of seeing these whales
before they surface by wearing polarized sunglasses.
Polarized lenses cut down the glare on the surface
of the water and will enable you to see the
blue-green shadow of the whale before it breaks
the surface – allowing you to get ready
for that once-in-a-lifetime photograph. It is
also a good idea to use a polarizing filter
on your camera to increase the contrast and
eliminate the glare from your images.
California is a whale-watchers' paradise.
There are few other places that harbor such
a concentration and diversity of whales. Although
there are reports of blue whales being seen
throughout the year in Baja, the best time is
January through April. Blue whale ‘hot-spots'
are found near Loreto and the surrounding islands
of Monserrate, Santa Catalina and Santa Cruz
and in the lower part of the Sea of Cortés.
There are day trips offered from a number of
Baja's port towns, but the best way to
see blue whales is to immerse yourself in their
environment, and to take to the water for extended
periods of time.
it is their size, our perception of their gentleness,
their interaction with others of their own kind,
or the tales founded in myth, legend and reality
of their interaction with humans that attracts
us. Or maybe it is the knowledge that we came
so close to losing them. No matter what the
reason, there are few people who are not awed
at the sight of a great whale ascending from
do not know how many whales are left, but as
development continues along our coasts, it is
becoming even more important that we take the
time to study the whales and learn their secrets.
If we do not, we may soon find the oceans silent,
and the surface stilled. The world's oceans
were once filled with blue whales, today the
sight of a whale blowing on the horizon is sadly
rare, except perhaps in the beautiful waters
that surround the Baja Peninsula – a sight
to be cherished.
Gilders was born in Hitchin, England and received
her Bachelor's and Master's degrees
in Pure and Applied Biology at New College,
Oxford University. She is the author of "Reflections
of a Whale-watcher" (Indiana University
Press, 1995) and "Crossing Alaska"
(Graphic Arts Publishing Company), due out in
June, 1997. Michelle lives in North Vancouver,
British Columbia, where she works as a writer,
biologist and photographer. She travels extensively,
including annual trips to Baja, mainly in search
of marine mammals. Her ultimate goal is to observe
for herself all of the eighty recognized species
of cetaceans. Copies of "Reflections of
a Whale-watcher" can be ordered from Indiana
University Press at 1-800-842-6796.
tour operators run whale-watching trips at the
time when blue whales frequent Baja's