Ask
a Marine Scientist:
answers to Mammals questions!
Choose one of the following:
- Suborder
Odontoceti -Toothed Whales (Dolphins, Porpoises,
Killer & Sperm Whales)
- Suborder Mysticeti -
Baleen Whales (Gray Whales, Blue Whales, Humpback
Whales)
- General Whale Biology -
Whale Biology, Whale Populations, Whales & Humans
- Seals, Sea Lions, Walrus, Manatees,
and Sea Otters
ASK
A SCIENTIST: ANSWERS TO QUESTIONS
Odontoceti
"Toothed Whales"
Index to Questions
DOLPHINS
KILLER WHALES
BELUGAS
NARWALS
TOOTHED WHALES
DOLPHINS
 Pacific
Bottlenose Dolphin Range - from Maxwell
Kelly in Northern Alberta, Canada
Q: I was wondering if the
Pacific Bottlenose Dolphin lives up around Vancouver. If not,
how far North do they come?
A: The Pacific Bottlenose
Dolphin does not live around Vancouver. The range of the bottlenose
dolphin in the Pacific Ocean starts in southern California and
northern Japan and extends to southern Australia, New Zealand
and Chile.
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Dolphin
Brains - Received from Dodie in California.
Q. What is the size & capacity of the frontal lobes in a bottle nose dolphin.
I want to compare it with the human brain frontal lobes. Do dolphins have two
sides to their brain like humans? If they do, do you know which side they operate
from most often...whether it be their right side or left side?
A. A comparison of the actual weight of brains is not normally used to
compare species, due to the variation in the sizes of the animals. The weight
of the brain as a percentage of body weight is about 1.9 % in humans, and varies
between 0.25% and 1.5% in toothed whales (with the dolphin being at the higher
end of the spectrum). Perhaps a better measure of comparing mental development
between species is the Encephalization Quotient (EQ) which is the ration of
the brain volume to body surface area. The EQ of humans is 7.4, of Chimpanzees
2.5, most other mammals less than 2.0. The EQ of the bottle nosed dolphin is
5.6, the highest value of all whales.
It is believed that dolphins have the ability to put one half of their brain
asleep while resting. This allows them to remain alert. They then can switch
1/2's and rest the opposite side. More information about this topic may be
found in "The Bottlenose Dolphin" Edited by S. Leatherwood and R.R.
Reeves. San Diego: Academic Press, 1990. There is a chapter on "The Central
Nervous System of the Bottlenose Dolphin"(pp. 69-97) by Sam Ridgeway.
It also has an extensive reference list if the information wanted is not there.
There is a more extensive discussion of this possibility in this chapter.
Reviews of cetacean brains may be found in :
Ridgeway, 1986 Dolphin Brain Size. In: Bryden, M.M and Harrison, J.R. (eds.),
Research on Dolphins, Claredon Press, Oxford pp 59-70.
Morgane et al. 1986. Evolutionary aspects of cortical organization in the dolphin
brain. In: Bryden, M.M and Harrison, J.R. (eds.), Research on Dolphins, Claredon
Press, Oxford pp 71-98
Morgane et al. 1986. Evolutionary morphology of the dolphin brain. In: Schusterman,
R. J., Thomas, J.A. and Wood, F.G. (eds.), Dolphin Cognition and Behaviour:
A comparative approach, Lawrence Erlbaum, Hillsdale NJ, pp 5-29..
Answered by Treva Ricou
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Colour
Vision in Bottlenose Dolphins - Received from Alex
Drozd in Pittsburgh, PA
Q: Do bottlenose dolphins
see in colour or in black and white? Thank you.
A. Dolphins can see some colours,
however seeing a full spectrum of colour is not as important
for water animals as it is for land animals. At the surface of
the ocean all the colours can be seen, but in deeper water everything
appears blue-green. Down at about 200 meters there is no colour
left at all, the sea is pitch black. So although at the surface
its important for dolphins to see some colours, they are a diving
animal and spend a lot of time down in deeper waters, so being
able to see in colour isn't as important.BACK
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Dolphin
Births - Received from Allisha in Kansas.
Q. When is a good time
to see a Dolphin being born?
If you are talking about seeing a dolphin being born in an aquarium, this can
happen at just about any time of the year. Aquarium staff know if one of their
dolphins are pregnant, and usually will let the public know if one of their
animals is "expecting". Usually though, members of the public are
not allowed to actually witness the birth of a dolphin.
Not many people have been lucky enough to see a dolphin being born in the wild.
Unlike the baleen whales like the grey whale or the humpback whale that have
a distinct breeding cycle, dolphins, along with other toothed whales, do not
have as distinct seasonality in mating and birth. This means that there is
no distinct place or time when you could say for sure that dolphins were being
born in the wild. BACK
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Dolphin
Music? - Received from Michelle in Los Angeles.
Q: Is the noise that dolphins produce, is is art(ie.music) or a way for them
to comminicate?
A. Dolphins (along with whales) certainly do make a variety of sounds underwater.
These sounds are used primarily to communicate, and also may be used as a kind
of "sonar" to detect objects underwater. See the question on Whale
Communication on this page for more information.
About dolphins and music: It has never been shown that dolphins make noises
strictly for their own pleasure. Of course, human artists have incorporated
whale and dolphin sounds into their own musical work. BACK
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Dolphin
Longevity - Received from Peter in Missouri.
Q How long does the average dolphin live?
A. It's sort of hard to say what the "average" dolphin is, since
there are 32 species of oceanic dolphins (Delphinidae family) and six porpoise
species (Phocoenidae family). There are five river dolphin species (Platanistoidea
family) found in five different rivers.
In general, smaller species live shorter lives than larger ones. The small,
harbour porpoise is thought to live about 15 years, The bottle-nosed dolphin
for 25 years, and the killer whale (which is in the dolphin family) for 50+
years for males and 80+ years for females. BACK
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Dolphin
intelligence papers - Received from Louie in the Northeast
Q: Where can I find some
specific research on the intelligence of dolphins. I am doing
a paper contrasting their intelligence with that of humans.
Thank you
A. I looked around
a little bit, and a few names popped up. Quite a bit of work
was done in the mid-60s on dolphin intelligence in conjunction
with the US Navy Dolphin Program. If you search the internet
using DOLPHIN INTELLIGENCE, you will find several pages that
discuss some of these experiments and their possible implications.
Herman, Markey, Batteau and Pryor are names that come up often
in the material that I have read. You may want to try doing a
journal search using these names. The Cambridge Scientific Abstracts
page is a useful one for journal searches. It can be found at
http://www.csa.com, and your home university should have a subscription
(you need a username and password). So try some of these places
and let me know what you come up with. Good luck. BACK
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Do
Dolphins Hibernate/Migrate? - Received from Mike in Indiana.
Q: Do dolphins migrate or hibernate (either or neither)?
A. No, dolphins do not hibernate - in fact they can only sleep for relatively
short periods of time, as they must rise to the surface and take a breath occasionally.
In general, dolphins do not migrate, at least not the same way that the Gray
Whales migrate from Baja California northward up the West coast of North America,
or the way that Humpback Whales migrate yearly from feeding grounds in Northern
seas to breeding areas in tropical seas. The susu, or Ganges River Dolphin
does "migrate" in that it is confined to main river channels during
the dry season, and then disperse into tributaries and creeks when the yearly
rains come. BACK
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Communicating
with dolphins - Received from Amara in Missouri.
Q Do you think that someday we will be able to communicate with dolphins? If
so how?
A. The term "communicate" can have a very broad definition. Communication
in animals can be very simple (eg. birds using song to communicate that they
own a territory, or a butterfly using bright colours to communicate to birds
that it tastes bad). It can also be more complex (eg. wolves communicating
with each other while hunting). Communication can be defined as the process
of transmitting a message to another animal. In fact, you could say that we
communicate with our dog when we send it to fetch a ball.
Various experiments have shown that dolphins are capable of quite complex communication.
Dolphin make a wide variety of sounds, some of which have been shown to be
used in social situation. Courtship, distress, and aggressive confrontation
all have their own particular sounds associated with them. Other sounds may
be used to identify particular animals, and to keep groups together while foraging.
Dolphins can also learn to mimic sounds very rapidly and accurately.
Louis Herman and his colleagues in Hawaii have worked extensively with the
subject of language and two way communication with dolphins. They have shown
that dolphins are capable of understanding simple auditory or gestural language
elements even when they are combined into two-word or three-word sentences.
Dolphins trained to respond to these commands have then been shown to be able
to report to other animals that a particular object is present or not in their
tank. These and other studies show that dolphins are capable of communicating
complex concepts.
However, dolphins may not use these abilities in the wild. All attempts to
demonstrate the existence of a "natural language" in dolphins has
been unsuccessful. It appears that while we may be able to communicate to a
certain extent with specially trained dolphins, we will not be able to actually
have a conversation with them. BACK
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Dolphin
tails - received
from Harry in Chicago.
Q: Are Dolphin Tails real tails (vertabrae (sp?) column)
where are the legs? Do some marine mammals have the legs
adapted/evovled into tails ?
 A:
Yes, dolphin tails are true tails extending from the vertebrae
column.
Some cetaceans (whales and dolphins) have remnants of the pelvic bone in
their bodies that do not seem to have a function. This bone is evidence
of the cetaceans' evolution from an ancestral 4-limbed ancestor.
There is mammal known to have evolved a tail from legs.
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Dolphin
mortality and tuna - Received from Shelley in Missouri.
Q: About how many dolphins are killed a year by tuna nets or by people catching
them accidentally?
A. Dolphin mortality from the tuna fishery has dropped dramatically since
the 60's, when it was estimated that 100,000 or more dolphins were killed in
fishing nets each year. Because of better fishing practices, this figure has
been reduced by 96%. Last year, there were only about 4,000 (some reports say
3,609) dolphin deaths caused by tuna nets.
For two very opposing views about the future of tuna fishing and what we should
do about dolphins being caught in nets, see the High
North site in Norway.
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Sleeping
dolphins - Received from the Fifth Grade Class at
H.E. Corley Elementary School.
Q: We were surfing the
net looking for information about dolphins and came upon your
website. We were interested in knowing why dolphins do not
stay at the surface when sleeping.
A: Sleep
or rest in wild schools of dolphins is not commonly observed.
Biologists believe that when dolphins sleep, one half of their
brain is kept alert while the other half is resting. One reason
for this is because, unlike humans, breathing in dolphins is
voluntary and not under the automatic control of the central
nervous system. A typical sleep pattern for dolphins appears
to consist of slowed swimming, aggregation of school members
into a more tightly packed group and changes in diving rhythms.
A study of spinner dolphins
(Stenella sp.) demonstrated that just before a rest period,
the dolphins swim inshore from deep water feeding grounds. Once
in the rest area, the group slows down and the dolphins move
closer together to the point of actually touching. As opposed
to shallow diving in the active school, the resting school exhibits
deeper dives of longer duration. Surface times are significantly
reduced, with the dolphins only coming up for a few breaths and
then quickly re-submerging. It is believed that this behaviour
serves to reduce the risk of predation on the resting group.
If the dolphins remained at the surface while resting, they would
be a more obvious target for predators. BACK
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Dolphin
and human genetic relatedness - Received from Bill in New Jersey.
Q: I am trying to find out all that I can about dolphins and humans and how
they are genetically related (if we are)? any help would be much appreciated.
A. All
animals are genetically related to each other in some ways. Some
animals are more closely related to humans than others. For example,
a mouse (mammal) is much more closely related to a human (mammal)
than is a clam (mollusc).In terms of how "related" two
animals are, you really have to consider the level that you're
looking at. For example: Dolphins are mammals, so they are genetically
more related to humans than clams are. If you are looking at
how dolphins and humans are related compared with all of the
different mammal groups, you'll find that they are not very closely
related. Often, biologists will construct a "cladogram" to
show how different groups of organisms are related. It is a branching
structure - related groups are shown closer together. In a cladogram
of the different mammal orders, humans (primates) are closely
related to orders such as Chiroptera (bats), and Insectivora
(shrews, moles, hedgehogs). Porpoises are in the order Cetacea,
and are more closely related to the order Artiodactyla (deer,
cows, etc.) BACK
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Dolphin
signature whistles - Received from James in Kingston, Ontario.
Q: Hello, I'm working on a project at Queen's University in Kingston, Ontario.
The project entails the evolution of communication systems within dolphin species.
In particular, I would like to know if you have any information dealing with'signature
whistles'. I am trying to determine if the 'last name' of the signature whistle
is genetically determined, or if it is learned (passed down from the maternal
parent).
A. In the bottle nosed dolphin,
the mother often whistles continuously shortly after birth. This
whistling may go on for several days. Initially, the mother's
whistle is quite uniform, but then it acquires a "signature" characteristic
which is presumably used for individual recognition. If this "signature" was
genetically determined, the mother would have no need to whistle
continuously to her offspring right after birth. She does this
presumably in order to "teach" her offspring the signature.
Many animals including birds and mammals use individual vocal
recognition to maintain parent-offspring bonds. While the ability
to quickly learn to recognize a specific individual vocalization
may have some genetic basis, the young animal is not born recognizing
its mothers vocalizations - learning must still take place.
For more information, see:
Caldwell, M.C. and Caldwell,
D.K. 1979. The whistle of the Atlantic bottlenosed dolphin (Tursiops
truncatus) - Ontogony. In Winn, H.E. and Olla G.L. (eds.),
Behaviour of Marine Animals vol 3: Cetaceans, Plenum Press, New
York, NY, pp. 369-401.
Herman, L.M. and Tavolga,
W.N. 1980 The communication systems of cetaceans, in: Herman
L.M. (ed.), Cetacean Behaviour, Wiley Interscience, New York,
NY, PP 149-209. BACK
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Dolphin
food and diving- Received from West Virginia.
Q: 1) How far down can
a Dolphin Dive? 2) What do dolphins eat?
A.1) There
are many different species of dolphins. The depth that they dive
to generally depends on what sort of fish they usually eat. A
river dolphin such as the Ganges Susu would not have to dive
as deeply to get fish as an Atlantic White sided dolphin. Dolphins
usually don't dive very deep, and certainly don't hold the record
for cetaceans. The sperm whale has been known to dive as deep
as 3000 meters!
2) Again, there are
many species of dolphins, and they eat a wide variety of types
of fish. BACK
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Dolphin
blowholes - Received from Jenna.
Q: Do dolphins breathe
with both their blowhole and their mouth?
A: All
cetaceans (whales, dolphins and porpoises) breathe only through
their blowholes, which are situated on or near the top of the
head. Blowholes are similar to nostrils in other mammals, serving
as openings to the respiratory passages. Baleen whales (e.g.:
humpback and gray whales) have two blowholes side-by-side, while
toothed whales (e.g.: dolphins and sperm whales) have only one
blowhole. Cetaceans cannot breathe through their mouths, because
the trachea (air passage) and esophagus (food passage) are completely
separate. The trachea connects only to the blowhole. BACK
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Relationship
between sharks and dolphins - Received from Lisa in
Los Angeles.
Q: Please tell me about
the relationship between sharks and dolphins. I am specifically
interested in whether dolphins attack sharks and how they interact.
A: Dolphins
and sharks are both top-level predators in the marine environment.
Its difficult to generalize about interactions between these
organisms because there are so many different species of sharks
and dolphins, so instead I'll provide a couple of specific examples.
A study of bottlenose dolphins
(Tursiops truncatus) off Natal, South Africa determined
that approximately 2.2% of the dolphin population were preyed
upon by sharks. An additional study of a T. truncatus population
in the northern Adriatic Sea found poor evidence of shark predation.
However, when considering calves and juvenile dolphins the mortality
rates appear much higher. A study of dolphins in Shark Bay, Western
Australia demonstrated that 35% of calves did not survive past
the first year, while 50% of the remaining juveniles did not
survive past weaning. The main cause of death was believed to
be heavy predation by tiger sharks (Galeocerdo cuvier),
as demonstrated by the high incidence of shark scars on adult
dolphins.
One of the only documented
instances of a dolphin attacking a shark occurred in late 1997
off the coast of the Farallon Islands. A female killer whale
(Orcinus orca) attacked and killed a small great white
shark, although she did not consume it. Biologists believe this
is an isolated incident, and not indicative of typical interactions
between sharks and killer whales. There are two first-hand reports
of this incident on the Shark
Research website.
(Thanks to Hugh Finn for assistance
with this answer)
References:
Bearzi, G., G. Notarbartolo-Di-Sciara
and E. Politi. 1997. Social ecology of bottlenose dolphins in
the Kvarneric (northern Adriatic Sea). Marine Mammal Science,
vol 13, no 4, pp. 650-668.
Dudley, S.F.J. and G. Cliff.
1993. Some effects of shark nets in the Natal nearshore environment.
Environmental Biology of Fishes, vol 36, no 2, pp. 243-255.
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Dolphin/human
physiology - Received from Erin in Upstate NY.
Q: I have to write a paper
at school about Human Physiology. I would like to find out
any information about the study of Dolphins used interchangably
with the Human Physiology. Please give any information that
you can, including possible web sites where I can access any
information that I need. Thank you.
A: I
assume that you're looking for information on the comparative
physiology of humans and dolphins (e.g. comparisons of visual
acuity or hearing abilities). Quite often, general books on mammalian
physiology will have this type of information. Head down to your
university/college library and search the indexes, in addition
to looking for journal articles using Biological Abstracts. Ask
at the reference desk if you need help using the databases.
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Tool-using
Dolphins - Received from Trish in Oregon
Q: I have to write a research
paper for my biology class dealing with animal biology. I found
an article in the searchbank at the college about dolphins
with a cone-shaped sponge over its beak in Shark Bay, off Western
Australia. The article was in Discover, March 1998 v19. It's
really vague. I'm having trouble finding any other articles
pertaining to this one. There are million's of articles about
dolphins but not the "Shark Bay dolphins". Can you
help?
A: Well,
I can try. I seems to
me that scientists can only speculate as to why these dolphins
exhibit this behaviour. They seem to think that they use the
sponges as protection against the poisonous spines of stonefish
and stingrays. Another speculation is that the sponges could
be used to stir up prey from the sea floor while avoiding these
stings. If you use a search engine and look up "shark bay
sponge" you may come up with more results. I used Hotbot
and it came up with over 300 hits (although I'm not sure how
useful most of these would be).
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Dolphin
Sex - Received from Adam
Q: I've heard how dolphins
reproduce, but couldn't understand it well enough. Can you
explain from step 1 on (mating rituals, dances, procedures,
etc.)? Thank you for your help. Thank you.
A:Here's
what I could find on dolphin mating habits. The readiness of
females to mate is given to surrounding males by cues such as
change of shape and colour of the genital area, body language,
and possibly by hormones release in urine and feces. Courtship
leading up to mating involves belly contact between the pair,
sometimes upright, and sometimes lying horizontally. When horizontal,
the male usually swims beneath the female. This courtship may
be practised by animals of any age and sometimes by animals of
the same sex, and at different times of the year. Courtship doesn't
always lead to mating. Courtship rituals include chasing, simultaneous
surfacing, breaching, and flipper contact, as well as vocalizations.
When it comes time to mate, the pair hold onto each other with
their flippers, the male's penis comes out of the genital opening,
and internal fertilization takes place.
The gestation period for most
toothed whales is between ten and twelve months.
When the calf is born, the
mother takes it to the surface for its first breath. Then she,
or another female, bites through the umbilical cord. Throughout
the calf's youth, assisting females, or "aunts" will
aid the mother and calf by providing extra protection and surveillance,
as well as baby-sitting the calf while the mother goes off to
feed. The calf relies on its mother for milk for 18-20 months,
after which it can feed on solid food.
As the calf gets older, it
socializes more with other animals and spends less time with
its mother. Eventually, the calf will leave its mother and form
a group with other individuals of similar age. BACK
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Dolphins
and the Titanic - Received from Darrell Nave in Tracy,
California, USA
Q: In the movie TITANIC
we are shown dolphins playing in the bow wave of the ship as
it leaves Ireland in April. Is this realistic?
1) Dolphins in the north Atlantic?
2) In the month of April?
3) Of a type that would play in a bow wave?
Thank you in advance for your answers.
A: First, yes there are dolphins
in the north Atlantic in April. The scene where the dolphins
are riding the bow wave is a day or two into the trip which would
put the Titanic southwest of the British Isles in the Gulf Stream.
However, when they show the dolphins in the movie they switch
between two species dolphins, the common dolphin (Delphinus
delphis) and the bottlenose dolphin (Tursiops truncatus).
Both of these species could be found in the north Atlantic Ocean
in April and both species would ride the bow wave. So it would
be correct information if they had not switched between the two
species.
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Dolphins's
Age - received from Chris in Holbrook, MA
Q: How old do dolphnis live
to
A: Great Question!
It is quite difficult to measure
the life-span of a dolphin in the wild because dolphins live
for so long (possibly as long as the researcher who is trying
to track it.)
One way to find out the age of a dolphin is to look at its teeth: As a dolphin
grows, it lays down layers of dentine on the inside of each tooth. If you remove
a tooth and cut through it, you will see these layers. The number of layers
you count will indicate the age of the dolphin.
The oldest known dolphin in the wild was found to be 51 years old. Most dolphins,
however, have a far shorter life-span. One study has estimated the life-span
of the bottle-nosed Dolphin to be 25 years.
I got most of this info from a great book called "Dolphins of the World" by
Ben Wilson, 1998.
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Dolphin
bellybottons - received
from Elizabeth in Franklinton, CA.
Q: Do
Dolphins have bellybuttons? If so what are they there for?
A: Yes, dolphins have belly
bottons.
Belly buttons are actually just a scar that remains from a baby's severed umbilical
cord. The umbilical cord is vital to a developing baby (the fetus) within it's
mother, because it connects the fetus to the placenta, an organ where materials
are exchanged from the mother's blood to the fetus' blood. This is the only
way that a developing fetus gets the nutrients that it needs, and gets rid
of its waste. The materials are carried in the baby's blood that runs to and
from the placenta, through the umbilical chord. The umbilical cord is therefore
very important.
There are three types of mammals:
monotremes: egg-laying mammals
example: the platypus
marsupials: pouched mammals
example: kangaroo, opossum...
placentals: mammals that develop a placenta
(most familiar mammals in North America.. including whales and dolphins)
All placentals hve belly bottons.
Thanks for the great question!
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Are
dolphins bald? - received
from Jeffrey in Fallbrook, California.
Q: Are dolpins bald?
A: Yes, dolphins are bald!!
Cetaceans (whales and dolphins) are unique among mammals because
their dermis does NOT contain any hair follicles, sebaceous
or sweat glands. Dolphins have thick layers of blubber for
insulation instead of hairs. Their epidermis is 10-20 times
thicker than human skin and is lined with hydrodynamic ridges.
Its thickness helps to maintain the skins rigidity in the water
and the ridges allow fast dynamic swimming. Check out these sites:
Dolphin Biology Research Program
The Wild Dolphin Project
Thanks for the question!
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Dolphin
Genders - received
from Julia in Iowa.
Q: How can you tell if a dolphin
is a boy or a girl?
A: Great question!
For some dolphins it is easy to tell the difference between sexes, and for
others it is more difficult. Killer wales are dolphins, and female killer
whales are quite distinguished from males by the shape of their dorsal
fins. Males have a long and straight dorsal fin, while females have a
shorter and curved dorsal fin.
In most dolphins, the male grows to be longer and bulkier than the female.
But this is not very helpful if you see one or two dophins in the wild and
you don't know if they are the same age.
A reliable way to distinguish malee from female dolphins is to have a look
at their lower belly. Males have two slits on their lower abdomen, one longer
one called the genital slit, and one shorter one called the anal slit.
Females have one long slit which does the job of the genital slit and the
anal slit. (the job is to contain the genitals and the anus, while the dolphin's
body remains streamlined). The female has two small slit on either side of
her long one, which contain her tits, from which her babies can suckle milk.
Their lower bellies look
something like this:
It is not likely that you
will be able to see these marks on a dolphin in the wild, but
this is how the biologists that work with dolphins tell them
apart.
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River
dolphins - received
from Michelle in Guyana, South America
Q: I am looking for information
about river dolphins and whether they compete for the same
fish resource as local fishermen?
A: As far as I can tell,
the dolphin in your area is Inia geoffrensis (Boto, Amazon
River, Pink Porpoise, or Pink dolphin. This species feeds on
crustaceans, catfish and small freshwater fish. The ICUN lists
this species as "vulnerable". There are many threats
to this dolphin due to increased human development in its habitat.
They become tangled in fishing nets, are hunted, affected by
heavy metal pollution coming from gold mines, and damming for
hydroelectric power often separates the dolphins from their
food source. I am sorry that I couldn't find more specific
details on the species of prey the Boto eats, or if their prey
conflicts with commercially fished species. However, there
are so many threats to this species, it would be easy to come
up with many conservation based projects. The following websites
may be useful as well: International Society for the Preservation of the Tropical Rainforest
and Sea World
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Dolphin
Pox - received on
from Deborah
Q: What is dolphin pox? Does
it kill dolphins?
A: Dolphin pox is a skin disease
of cetaceans. Both free-living and captive dolphins have been
prone to show these skin lesions. The lesions are discrete, raised
or smooth, round to irregularly round groups of pigmentation
that form rings ranging from 1 to 5 cm in diameter.
Electron microscopic studies of the lesions have revealed viral particles consistent
with a poxvirus. The development of these lesions is thought to be associated
with stress, poor environmental quality, and poor general
health of affected dolphins. A study done by Baker, concluded that of the cetaceans
surveyed in his study, 69% were infected by some kind of skin lesion. Some
were caused by trauma and others were from a viral infection by the poxvirus.
However, from lectures I have attended by marine mammal pathologists in British
Columbia, my understanding is that although skin lesions are almost always
present in stranded cetaceans, they are rarely if ever the cause of death.
Sometimes the opening of such a viral infection can reduce immune repsonse
and contribute to further contractions of bacterial diseases.
I found this quote in one study: "It does not appear to be detrimental
to cetaceans, and is generally a self limiting disease." and also. "Although
this virus does not appear to cause serious illness in cetaceans, the development
of these lesions usually occurs in periods of poor health and stress".
So, the pox doesn't kill dolphins, it only can deteriorate their health enough
to make them susceptible to other diseases.
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Dolphin
Senses - Reseived from Bonnie
Q: How do bottlenose dolphins
excrete? Also, how would bottlenose dolphins react toward bright
light chemicals and sharp objects?
A: Dolphins have very well
developed sense. They have excellent eyesight - but this is only
beneficial near the surface, where light still penetrates through
the water. At greater depths, dolphins use echolocation (a series
of clicks that rebound off of objects to inform the dolphin about
the distance away and size of objects in their surroundings)
to "see". Although it is not clear if dolphins can
smell, they can taste, and can sense chemicals (they can use
pheromones to communicate). They also have very sensitive skin,
which also plays a role in communication, and they are able to
feel pain. So, dolphins could sense and react to bright light,
chemicals, and sharp objects - but I could not find anything
specific enough to say how. It probably varies with the individual
dolphin, but if the sharp object produced pain or if the chemical
was unpleasant, they would probably move away from it.
Dolphins have genital and anal slits on their bellies. As mammals, they would
excrete similar to the way other mammals do.
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Captive
dolphin release -
received on from Erin and Abby in Maryland
Q: If dolphins are kept in
captivity, can they ever go back to their natural habitat? Are
they excepted back into the pod?
A: This is a great question!
There is much debate and controversy surrounding the release
of captive dolphins and whales. Sometimes, the animals are only
in captivity temporarily, for rehabilitation purposes, and then
are released. However, it is much more difficult to release a
dolphin that has been in captivity for many years, or that was
born in captivity. Some concerns are that the dolphin won't know
how to catch its own food, that it won't fit into the complex
social structure of wild dolphins, that it will transfer new
diseases to wild dolphins, that the captive dolphin will have
a weakened immune system and more easily develop a disease...the
list goes on and on. Many marine mammals have complex social
structures. Killer whales, for example, have dialects that vary
from pod to pod. Each pod consists of a family group, the head
of which is the maternal female. It is difficult to return a
captive Orca, especially if people do not know what pod they
came from. One way aquarium staff may prepare a whale for a return
to the wild is to play tape recordings of vocalizations from
the whale's pod. There are many people who believe that all captive
animals should be returned to the wild. I am sure you have heard
the story of Keiko, the whale from the movie "Free Willy".
A lot of money has been spent to prepare Keiko for a release
into the wild, but it is unclear whether he will ever be ready.
There are many websites dedicated to conservation groups who
disagree with keeping dolphins in captivity, and who support
the release of dolphins back into the wild.
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Dolphin
strandings - received
on from Nicole in Illonois
Q: If there was a beached
bottlenosed dolphin I would like to know how a person from a
rescue team would save this dolphin.
A: Strandings occur more often
in small toothed-whales and dolphins than they do for larger,
baleen whales. Dolphins sometimes strand alone or in groups of
20-30. Usually, if a whale is found stranded it is because it
had already died offshore. However, live strandings are believed
to occur when dolphins and whales make a mistake in reading the
Earth's geomagnetic field that they use for navigation purposes.
The navigation error may occur a couple of days before the stranding,
but the whale does not notice until it lands on the beach. There
is little hope in saving large beached whales, because they are
so heavy their weight crushes their internal organs once they
are out of the water. However, rescue efforts can be made to
return dolphins and smaller whales. Often, this is a difficult
process due to the size and disorientation of the animal.
After finding a stranded whale, one should contact the coast guard or police.
Standing well back, observe the whale to see if it is still alive (watch out
for thrashing tails). If the whale is still alive, try to keep the delicate
skin cool and damp using a towel or some seaweed. Take care not to cover the
eyes or blowhole. Even if the animal is dead, record information such as size,
species and location. One book recommends setting up different teams: to keep
the animal wet and cool, to keep curious observors away, to organize food and
warm clothing for volunteers, to prevent other strandings if there are more
whales near shore etc. If other whales are offshore, make note of numbers,
size and colour as well. An expert must be present to make the decision of
whether the dolphin is in good enough condition to be returned to the water.
Slings, tractors, or front-loaders can be used to transport the dolphin back
to the water. Their skin is very delicate, so they cannot be dragged and should
be handled gently. The animal will often be very dazed when it returns to the
water and may need to be supported by volunteers until it is able to swim on
its own.
Check out this webpage for
further information. OceanLink's Ocean Matters, Strandings page
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Sleeping
dolphins - received
on from Michele in Utah
Q: Do dolphins sleep? If they
do, then how?
A: Yes, dolphins do sleep!
It is believed that they "shut off" half of their brain
at a time while they are sleeping. The other half of the brain
remains functioning to allow the dolphin to continue to function.
After awhile, the two halves switch, and the other half of the
brain gets a chance to rest!
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Cows
and Dolphins
Q: What do Cows and Dolphins
Have in Common
A: You would be very surprised
to know just what cows and dolphins have in common. Well not
so much with cows/dolphins but more in tune with overall whale/dolphin
evolution.
Most scientists believe that whales/dolphins evolved from even toed ungulates
(hoofed animals) which includes modern day cows and deer. these early animals
were carnivorous much like todays wolves but their feet were like those of
cows and horses. Just like todays carnivores these whale predecessors have
several different kinds of teeth. overtime these hoofed ancestors of the whale
adapted to their marine environment and eventually became the cetacean species
that we know and love today.
In terms of direct comparisons between the cows and dolphins they are both
mammals and vertebrates. Cows likely have more in common with baleen whales
(in terms of cross species comparision) because baleen whales are the grazers
of the ocean. Cows on other hand are the grazers on land. Dolphins are carnivores
and usually eat other fish.
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Dolphin
Age Distinctions
Q: What is a Dolphin called
after a calf?
A: Most of the time a dolphin
is called a sub-adult or a juvenile after it is no longer a calf.
Some scientists may call a juvenile dolphin a teenager as a joke.
KILLER WHALES
Killer
Whale Markings - Received from Kevin in Ontario.
Q. Do the markings on killer whales specific to which pod they belong to?
Hi Kevin: The marine biologists studying killer whales in British Columbia
have identified pods of whales through their vocalizations and dialects. The
marks on dorsal fins and the shape of the saddle patch vary so that individual
whales can be identified, but there is no link between the markings and dorsal
fin within the pod. The dorsal fins of transient whales that range in the open
ocean are more pointed than those of resident killer whales that are found
in the waters around Vancouver Island and Puget Sound.
See you on the water sometime!
Answered by Margaret Butschler, Vancouver Aquarium.
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Whatever
happened to A57? - Received from Bonnie on Vancouver Island.
Question: I would like to know the answer to A57's demise. The paper reported
the death with autopsy to follow, I haven't heard anything since about cause
of death. Seeing this is the second whale in 2 yrs. to have died near Powell
River could there be a connection? Maybe too polluted with chemicals?
A. For
those who may not know, A57 is the code number for a resident
Killer Whale that lived in the waters around Vancouver Island.
The whale was found in distress in late 1996, and died shortly
after.
According to the people that
examined A57, the whale died of a massive bacterial infection
that was caused by an infected tooth. The bacteria that caused
the infection is called Erysipelothrix, and it is known in fish,
marine mammals, and some domestic farm animals.
It does not seem likely that
marine pollution played any role in A57's demise. This was in
all likelihood a completely natural event.
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Orca
Questions - Received from Nicole in British Columbia.
Q: Since I absolutely love
orcas, I would like to know:
1) What is the proper name
Orca or Killer whale? Personally I like Orca, but is that right?
2) Generally how long do
they live?
3) I live in B.C. Canada,
is it a good job to get into, work wise? I mean are there jobs
out there?
4) I've always wanted to
touch an orca, what does it feel like? Is it rubbery like they
say on "Free Willy"?
A:
1. Both
names are essentially correct. The name "Killer Whale" is
the common English name, while the scientific, or Latin name
is "Orcinus orca" The first part of the Latin name
is the genus, and the second part is the species. Many people
prefer the name "orca" because it does not have the
negative connotations that the term "killer" has.
2. For
ages of killer whales, see our OceanLink pages on Killer Whales
in B.C. and Killer Whales at the Vancouver Aquarium.
3. We
live in B.C. Canada too - congratulations on choosing such a
wonderful place to live! Please see our OceanLink pages on careers
in marine biology for more information on job prospects. It is
often difficult to find jobs working directly with marine mammals,
but it can be done if you are very persistent! If you live in
the Vancouver area, you might consider volunteer work at the
Vancouver Aquarium.
4. Yes,
touching an orca is quite the experience. I haven't seen the
movie, but the description sounds pretty good. The skin is very
very smooth to the touch, yet when you touch an orca, it feels
quite firm. The very thick layer of blubber under the skin means
that you can't feel any muscle tissue when you touch the animal.I'd
have to say that it feels very nice!
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Orcas
and pollution - Received from Rachel in Bellingham, WA.
Q: How is the Orca's environment being changed By pollution? Please be specific
about different kinds of pollution. I am doing this for a science fair project.
I would also like some info on how orcas communication.
A. It
is difficult to say how environmental changes such as global
warming or acid rain affect orcas and other cetaceans but water
pollution and habitat damage have certainly shown to be problems
for these animals. Killer whales, or orcas, are a top predator
in the ocean. This means that they sit at the top of the food
chain and have few, or no, predators. These animals also live
for a long time. Both of these things make them susceptible to
long-term accumulation of pollutants or toxins.
Killer whales are the last
link in a long line of food consumption. For instance, a killer
whale can eat 400-500 herring per day. Each herring might eat
about 7000 copepods (a type of animal plankton) per day which
in turn eat 130,000 pieces of phytoplankton (plant plankton)
per day. If a toxin is absorbed by the phytoplankton then the
toxin accumulates in each step in the food chain with the killer
whales receiving the largest "dose". As I'm sure you
know, killer whales also have a lot of fat, called blubber. Fat
generally tends to accumulate toxins so this is another reason
whales can be so susceptible to pollution in the food they eat.
Any problems that affect the
food or habitat of killer whales can affect these animals. Disturbances
when they are trying to rest, loss of food sources (the decline
of salmon on the west coast may very well affect whales too),
and habitat degradation, are all types of 'pollution' or environmental
problems that can potentially harm killer whales.
Answered by Adrienne Mason
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Orca
Rubbing Beach - Received from Amanda in Arizona
Q: Have you heard of "The
Rubbing Beach". Whales (primarily orcas) go there and
give birth and rub against the smooth peebles at the bottom.
It is very popular place. Where is it located? (State, city,
directions). Any other info you could give me would be great!
Thanks!!
A: The rubbing beach that
orcas visit that I am familiar with is in British Columbia in
Canada. It is located in the Johnstone Strait (north eastern
side of Vancouver Island near Telegraph Cove) in a a place called
Robson Bight. Robson Bight is located along a typical route where
resident killer whales forage and has several beaches that are
frequently used by killer whales for rubbing. In the past, this
site was frequently visited by whale watchers and there was a
huge amount of boat traffic in the area. The orcas stopped coming
to the area because of the excessive boat traffic. It was in
1982 that Robson Bight was made an Ecological Reserve by BC Parks
as a sanctuary for killer whales and to protect these important
rubbing beaches. People are no longer permitted in the area,
but there are a lot of other whale watching opportunities all
along the coast of British Columbia. I suggest you check out
the OceanLink Eco-Adventure page and search the net for other
whale watching companies which may be closer to you.
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Orca
classification - Received from Michelle in Boston
Q: Why are orcas classified
as dolphins ?
Killer whales (Orcinus
orca) are in the taxonomic family Delphinidae, along with
several other species of dolphin and porpoise. All of these
animals are odontocetes, which means they are toothed, cetacean
marine mammals.
Generally, the term whale
is used to indicate size rather than zoological affinity. "Whale" simply
refers to something that is rather large. Orcinus orca is
more closely related to dolphins and porpoises than any of the
other marine mammal families, and therefore it is considered
a dolphin. However, because O.orca is the largest species
in the dolphin family, these animals are sometimes referred to
as whales. If you find this confusing, you are not alone, because
the common nomenclature for these animals is not very consistent.
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Orca
colouration - Received from Nicole in B.C.
Q Why do only some of the orcas have the white spot on their back behind the
fin? Is it only some pods that have that? Does it mean anything?
A. Dr. John Ford from
the Vancouver Aquarium writes:
"I do not know of any
population without any saddle patch, although it is much reduced
in some regions. Most researchers believe that the the white
patches and grey saddle patch do serve as disruptive colouration
to confuse prey or to help coordinate cooperative foraging behaviours
by providing more concise visual markers."
Robin Baird and Pam Stacey
analysed the pattern of pigmentation of the saddle patch in 372
resident sand 99 transient killer whales from B.C., Alaska, and
Washington. They found that of the five different saddle patch
types, all were observed on residents, but only two occurred
on transients. In addition, saddle patch pigmentation patterns
were similar among clans of whales within a community. They suggest
that saddle patch shape may be inherited to a large degree, and
may be used to delineate stock of killer whales from other areas.
For more information:
Baird, Robin and Pam Stacey
1988. Variation in saddle patch pigmentation in populations of
killer whales (Orcinus orca) from British Columbia, Alaska
and Washington State. Can J. Zool. 66:2582-2585.
Evans, W.E., A.V. Yablokov
and A.E. Bowles, 1982. Geographic variation in the color pattern
of killer whales (Orcinus orca). Rep. Int. Whaling Comm.
32: 687-694.
Thanks to Lara Gibson for
assistance with this answer.
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Orca
Nickname - Received from Dalton Greiner in Pennsylvania
Q: Where did the Orca get
its nickname (Killer whale)?
A: Orca whales have the nickname "killer
whale" because they are actually kill other whales. There
are three types of killer whales and they differ in their feeding
and social behaviours. Transient killer whales, are the type
of killer whales that kills other whales. They feed on marine
mammals, such as seals, sea lions, whales, and dolphins. Resident
killer whales feed on fish, such as salmon. The third type of
killer whales is the offshore killer whales and these orcas feed
on fish as well.
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Orca
Lifespan - Received from Chrissy Alvarez in San
Antonio, Texas
Q: Do orcas live up to
25 yrs?
A: Female orcas will live
to be 50 years old on average, but some are known to live to
65. A male orca will live to be 30 years old on average, but
may live to be as old as 45.
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Offshore
Killer Whales - Received from Mona Wolfert in Port
Moody, BC, Canada
Q: When was it first discovered
that there is a third type of killer whale, the offshores?
Who made that first discovery? Where were they first noted?
Any other information you could give me would be much appreciated.
I am co-hosting a Pro-D day workshop on February 18th on Whales & Dolphins
in the classroom (across the curriculum) and would like to
include this newest category of orca. Thanks so much for your
help.
A: Offshore killer whales
were discovered the early 1990s (1990 to 1992) by the the Pacific
Northwest killer whale researchers consisting of John K. B. Ford,
Graeme M. Ellis, and Kenneth C. Balcomb. The offshore killer
whales first encounters took place near the Queen Charlotte Island
(Haida Gwaii) and 15 or more kilometres off the west coast of
Vancouver Island. Offshore killer whales tend to be found on
large groups of 30 to 60 individuals and are rarely seen in protected
coastal waters. Researchers believe that offshore killer whales
spend most of their time on the continental shelf, feeding on
schooling fish.
If you are interested in more
information on killer whales, an excellent source of information
is "Killer Whales" by John K.B. Ford, Graeme M. Ellis
and Kenneth C. Balcomb.
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Killer
whale skeleton - Received from Nicole in Madison,
NJ.
Q: How many bones is the
skeletal system of a killer whale composed of?
A: Killer
whales (Orcinus orca) generally have 50-52 vertebrae,
11-12 pairs of ribs and up to 21 phalanges in their first through
fifth digits. Mammalian skulls are composed of approximately
30 bones which make up the cranium, face and lower jaw. For more
specifics about whale anatomy, see the following reference: Tinker,
S.W. 1988. Whales of the World. Bess Press, Honolulu, HI. 310
pp.
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Where
to work with and learn more about Orcas? - Received from Joan
in Seattle.
Q: I live near the Puget Sound and am interested in participating in research
on orcas. Are there any opportunities for me and my children (ages 4 and 7)?
If not, where would you suggest to go to learn more about whales and dolphins?
We are homeschoolers, so even places with normal business hours are a possibility.
A. In your area, the best place to start would be the Center for Whale
Research, which is located in Friday Harbor, in the San Juan islands. They
undertake research programs, and are always looking for new members as well
as volunteers. Members receive current information about cetaceans, as well
as current research projects. They also have an interesting publication out,
geared for Orca lovers in the Puget Sound area: Orcas In Our Midst; the whales
that share our inland waters.
Center For Whale Research
P.O. Box 1577
Friday Harbor, Washington
98250
The center may also have other ideas regarding places that you may go in the
Seattle area to learn more about whales and dolphins.
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Why
Killer Whale Fins Flop Over - Received from Sarah
Fullbrook in Hope, BC
Q: You know how sometimes
when orcas are in captivity their fin can flop over. Is this
due to chlorine or chemicals in the tank?
A: Dorsal fins are supported
by cartilage just like your nose. When a male resident killer
whale goes through his "growth spurt" at around the
early teenage years, the dorsal fin grows really tall, really
fast.
Why is the fin bent? Well,
as the fin gets tall it also gets heavy. A whale with a straight
dorsal fin has spent lots of time in deep water, where the water
pressure keeps the fin upright until the cartilage hardens.
Resident Killer Whales that
went through their growth spurt in captivity have a bent fin
because the pools aren't deep enough to create the water pressure
needed to support the soft cartilage in the fin so the fin's
own weight makes it flop over. Once the cartilage hardens, the
fin is shaped forever.
Important Note: This phenomenon
is not restricted to captive whales, it has been spotted in wild
resident populations as well. The theory is that these whales
were spending lots of time in shallow bays and shallow feeding
grounds during their growth spurt.
Shallow water = low pressure.
low pressure + soft, heavy cartilage = bent dorsal fin
Answered by Todd Nivens from
the Vancouver Aquarium
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Killer
Whale Echolocation - Received from Elizabeth in Alberta,
Canada
Q: What is the difference
in echolocation between transient and resident killer whales?
How do the whales use sound to feed? How do the whales hunt?
A: Resident killer whales
travel in large, stable pods containing 10 to 20 whales and follow
predictable migratory paths. Residents eat mainly fish, especially
salmon. Foraging resident pods will spread out and form a broad
front that sweeps along narrow passages, often from shore to
shore. The pods move in a predictable fashion, from one good
feeding place to the next. When foraging for food, resident killer
whales exchange underwater vocalizations, pod members keep in
contact and perhaps alert each other of the presence of prey.
The whales will produce a series of rapid clicks that are used
to echolocate the salmon and for navigation. Once the fish prey
are found they are usually captured and eaten by the individuals
of the pod. By remaining in stable pods for generations, resident
killer whales can pass on their foraging knowledge and benefit
from previous generations.
Transient killer whales feed
on marine mammals, such as harbour seals, California sea lions,
Stellar sea lions, harbour porpoises, and Dall's porpoises, just
to name a few. Transient pods are not as stable as resident pods
and usually the pods consist of a mother and two or three offspring,
a group of unrelated females, but males usually forage alone
or may team up for a short time to catch a prey item. Transient
movement is unpredictable and they roam widely entering small
coves, bays, and channels in search of food. They dive for as
long as 5 to 15 minutes, where as resident killer whales only
dive for 3 to 4 minutes. Transients always forage in silence,
probably because their marine mammal prey would be able to detect
their presence if they echolocated. Instead of echolocation,
transients find their prey by "passive sonar", listening
for the sounds their marine mammal prey are making. Vocalizations
do occur when transients are killing and eating their prey. Transients
usually cooperate with one another when they are hunting large
prey, such as sea lions. The whales hit their prey with their
flukes to stun them and then prey item usually drowns. Transient
killer whales usually share their food.
Check out this website for
more information on killer whale research around British Columbia
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Do
Killer Whales Eat Humans - Received from Thomas Goodhand
from South-East of England
Q: I have heard that Killer
whales do not attack humans from a good source, if this is
true why not. Because they eat large marine animals such as
seals and their fellow dolphins so why not humans they have
come into contact with?
A: The type of killer whale
that feeds on marine mammals are transient killer whales and
they are not known to attack humans. Perhaps one reason is that
humans are not usually found in areas where they are hunting.
Another likely reason is that humans are not a very good food
source. Seals and dolphins have high levels of blubber in comparison
to other body tissue and are therefore good source of energy.
Humans do not have as much body fat and are not energetically
worth eating, the amount of energy it takes to consume humans
is not worth it in comparison to our nutritional value. This
has also been shown with many great white shark attacks. Most
great white sharks do actually consume humans, they are actually
just "tasting" us, it just so happens that their delicate
tasting is fatal to most humans.
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Captive
Killer Whale Behaviours - Received from Steve in
Texas
Q: First I must say that
I have got to be the biggest killer whale fan!
any ways, in the movie free willy when the boy (i think his name is Jesse)
fell and hit his head on the side of his tank and fell in the water and almost
drowned, would that really happen if a new trainer at sea world did the same
thing would most likely that whale do the same thing since killer whales are
supposed to be so friendly?
A: There have been incidences
where trainers have fallen in the water and if there are people
to help them out they are okay. However, one incidence happened
up in Victoria, Canada, where a woman fell in a tank with killer
whales when no one was around. They thought of her as a "toy" and
they pushed her around in the water and she eventually drown,
because no people were there to pull her out. The orcas did not
intentionally want to hurt the woman, but they had learned that
objects in their tank were supposed to be played with. This does
not mean that the killer whales were not friendly, they do not
understand that humans cannot play the same way they do and this
type of "playing" can be deadly to humans. I do not
know definitely that the killer whales at Sea World would not
push an unconscious person to the edge if they fell in the tank.
The whales would probably treat the person like they would during
their shows. So if the whales were trained to push a person to
the edge they would probably do that. Remember killer whales
do not understand that we cannot breathe and swim easily in water,
so they would probably not realize that a person needs to be
pushed to the edge to breathe.
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Orca
White Eye Patches - Received from Heriot in Indonesia
Q: Why do killer whales
have white spots by their eyes?
A: Killer whales actually
do not have their eyes in the white patches, but their eyes are
actually located under and in front of the white patch (see picture).
The white patches on their head can be referred to as false eye
patch. Both prey and predators usually attack the eyes of their
enemies, because the eyes are one of the most vunerable places
on an animal and if you can poke them the enemy will be blinded.
By tricking their prey or predator into thinking their eyes are
somewhere else, it will protect their eyes. So the trick worked
on you, just like it does on other animals.
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How
Orca Calves Are Born - Received from Laura Evans
in Alldavilla
Q: How do killer whales
have babies?
A: Killer whales are mammals,
just like humans and therefore they give birth to baby whales
(calves) similar to humans. Female killer whales reach sexual
maturity at 14 or 15 years of age. The gestation period is the
time between the female's egg being fertilized by a male (mating)
and the development of the young within the mother's uterus,
just like human babies development in their mother's uterus.
The gestation period is 16 to 17 months for a killer whale. If
you look at the underside of a killer whale you will see a belly
button because when killer whale calves are developing inside
their mother's uterus they are attached to her by an umbilical
cord, which provides them with all nutrients they need to develop.
On the underside of both males and females you will also see
a genital slit and below that the anus. A female killer whale
will also two mammary slits on either side of the top part of
her genital slit. The mammary slits are where the calves will
feed by drinking their mother's milk from their mammary glands
when they are developing. The genital slit of the female killer
whale is where the calf comes out when it is ready to be born.
When the female killer whale gives birth the calf leaves their
mother's uterus through the genital slit and enters the world.
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Measuring
Orca Populations - Received from Thomas B Goodhand
from the United Kingdom
Q: What methods do you
use for studying the distribution and abundance of Orca populations.
A: Current research being
done orcas in the coastal waters of British Columbia involve
taking photographs of individuals for the past 30 years and identifying
the individuals in pods by their dorsal fins, saddle patches
and other markings, such as scars and dorsal fin shapes. Photographs
are compiled from numerous different areas and are used to identify
migration patterns of the pods and their members. Underwater
acoustics are also used to identify specific pods. Resident killer
whales, like humans, have dialects that are specific to their
pod. Records of underwater acoustics are also used to identify
pods of killer whales. More recently, genetic work is being done
to determine how related different individuals are to one another.
I suggest you check out the research of Dr. John Ford.
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Why
Orcas Sing - Received from Zussette Perez in Portland
Oregon
Q: Why do orca's sing?
A: Orcas "sing" for
many reasons. Killer whales produce different kinds of underwater
acoustics (sounds) depending on the situation. One type is a
series of rapid clicks used for echolocation to find food, such
as salmon. Another type of underwater acoustic are sonar signals
that are used for navigation and detecting the whales's surrounding
environment. Killer whales use other kinds of sounds, mainly
whistles and burst-pulse signals that resemble squeals, squawks,
and screams, which are used to communicate with other individuals.
In fact resident killer whale pods have dialects. They are actually
the only other animal on earth, besides humans, that we know
of, that have dialects. Every killer whale pod has their own
dialect that is specific to their pod. Pretty amazing isn't it?
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A
White Orca -
received from Venessa in Idaho
Q: I've been
studying orcas since I was 5. In the book I am reading it talks
about "Chimo" a white Killer whale captured in 1970.
Is there such thing as a white orca????
A: Chimo did
exist, and was held at Sealand, a large public aquarium in Victoria,
B.C. for two years. Chimo was an albino orca, meaning that she
lacked pigmentation (colouration) in her eyes, skin, and hair.
Albinism is a heritable condition (meaning it can "run in
the family") that occurs in many animals, including humans.
An albino animal is perfectly normal accept it has no pigments
to give them the colour that you would expect. An albino human
is usually quite blond and has pale skin.
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Pioneer
killer whale research-
received from Luke in the Philippines
Q: Please tell me about the
pioneered names of researchers studying the killer whales. please
email back as soon as possible, thank you for your kind consideration.
A: Here are a couple of influencial
researchers of killer whales:
John Ford: PhD thesis in 1978 on orca sounds in Johnstone Straight. He had
a revolutionary hypothesis that different pods of whales had individual dialects,
and he basically figured out how they communicate, and haw they can learn sounds
from each other. Dr. Ford is now the curator of marine mammals at the Vancouver
Aquarium.
Micheal Bigg, Paul Spong, and others: 1970s - studied orca behaviour and how
they are linked to the movements of salmon in the Pacific Northwest. They found
that there were two distinct, independent groups (with different appearance,
behaviour, vocal patterns, and feeding strategies) . The two groups are the
residents and the transients. More recently, researchers have discovered a
third group, the offshores.
Here's a site with more info about the development of whale research in the
past 25 years
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Orcas
in California
Q: Can you tell me the normal
range for orca or killer whales to roam. In other words would
it be possible to see a transient orca pod as far south as Monterey
Bay or Morro Bay, CA?
A: Thanks for your question.
Apparently orcas live in all waters of the world except for the
high arctic. They are indeed sometimes spotted in and off shore
of California. Transient orcas from BC and Washington have been
identified as far north as alaska and as far south as Monteray
Bay.
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French
word for Orca - received
from Pamela
Q: What's Killer whale in
french?
 A:
Great question! Luckily we had several french students and researchers
here to help answer that question. There are two french terms
for killer whale:
orque or époulard
You can always use the scientific name too: Orcinus orca!
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Returning
Orcas to the wild -
received from Hayley in Hong Kong
Q: Will all Orcas that have
been in captivigy be put back in the wild?
A: It would be wonderful if
all Orcas could be safely returned to the wild, but I don't really
know if I can answer this. There are some problems with returning
animals back into the wild once they have been kept in captivity.
They may not know where to catch food, how they are supposed
to get it, and even what they should be eating. They also may
not have the survival skills for migration, or the social skills
for interacting with mates or competing for mates. There is also
a worry that Orcas that have been kept in captivity may carry
diseases that could be very dangerous to natural populations.
Having said that, there are programs aimed at reintroducing captive animals
back into the wild, but they are expensive and sometimes take many years.
Thanks for your question!
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Killer
whale localities -
received from Justin in Melbourne, Australia
Q: Where are most Killer Whales
found? e.g Which country?
A: Thanks for your interest
in Killer Whales! Thier scientific name is Orcinus orca. They
are second only to humans as the most widely distributed mammal,
and they live all over the globe! However, the highest concentrations
of killer whales are found in British Columbia, Washington and
Alaska, the Antartic, Norway, Iceland, and Northern Japan. Because
these whales move around alot and the ocean is a big place, we
don't know exactly how many exist or where they all are.
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Orca
Endangered? - received
on from Chrystina in Spearfish, SD
Q: Are Orca's an endangered
species?
A: You have asked a very
intriguing and contraversial question. Endangered species status
and legislation is a hot topic for many environmentalists and
biologists. Currently, killer whales are NOT listed as endangered.
In the USA, they do not receive any designation on the Endangered
Species Act, however are protected under the Marine Mammal
Protection Act. This act was set up in 1972 to control the
trade of marine mammal products and manage dwindling whale
populations. Killer whales have never been a highly commercial
species, although they are particularily popular aquarium whales
and many were caught and held in captivity in the 1960's and
70's.
Canada does not have an Endangered Species Act yet however we are working on
it. Canada does have an organization called COSEWIC (the Committee on the Status
of Endangered Wildlife In Canada). And as of May 2000, their new list featured
Northern Pacific resident Killer Whales in the "threatened" category
and Northern Pacific transient Killer whales in the "species of special
concern" category. The reasons for their addition to the list are:
1.Concern over dwindling salmon stocks in BC. Residents feed largely on salmon
and as i'm sure you've heard on the news, the number of salmon has been reduced
by overfishing, climate change etc.
2. PCBs: just recently a blubber sampling project of BC's killer whales was
completed by Dr. Peter Ross. He found alarmingly high levels of PCB contaminants
in killer whales. Especially transients. Because transcients feed at the very
top of the food chain (ie: the feed exclusively on other marine mammals) they
accumulate the most toxins
3. The numbers of killer whales in BC have been decreasing. Particularily in
the Southern resident pods, which have been decreasing in number for the last
5 years. Recent death of male killer whale J18 was caused by a severe bacterial
infection initiated by a external wound. It is not known if high levels of
toxins worsened his infection.
So, my opinion is that although killer whale populations globally are fairly
stable (and therefore do not warrant international "endangered" status),
the BC populations do deserve close monitoring and concern. We must be particularily
alert to further deaths in the diminishing pods of the Southern residents.
To keep up to date with endangered species and the killer whale situation in
BC, check out this site:
COSEWIC
Update on this question: As of mid-October 2000, the United States, under the
Endangered Species Act, has declared the North Pacific populations of killer
whales (including those in BC and Washington) endangered!
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Killer
whale reproduction -
received on from Dana in Virginia
Q: Do they mate with new males?
How meny babys do they have in a lifetime?
A: Not a great deal is known
about dolphin (orcas are the largest type of dolphin) reproduction.
Partially because labour only takes about an hour to complete,
so it is often not observed. The gestation period (the length
of time the female is pregnant is about 15 months). Females give
birth to one calf at a time, and rarely to twins. The calf remains
dependent on the mother for suckling, protection, and development
of social skills for several months to several years. In orcas,
the calf suckles from 1-2 years. However, the mother will often
reproduce or become pregnant again before the last offspring
leaves.
Orcas are polygamous - which means that the males mate with more than one female.
Females only have a short reproductive period every few years. As a result,
calves are born only every 1.5-4 years. In orcas, the calving interval may
range from 3-8 years. Female orcas become sexually mature ater 6-10 years,
and males become sexually mature after 12-16 years. The bottlenose dolphin
does not become sexually mature until 20 years of age! Due to this slow rate
of reproduction, most dolphins have a fairly lengthy life span (female orcas
may live to be as old as 70!). Larger dolphins only produce about 7 offspring
in their lifetime.
I couldn't fins out any specific information about how many calves are born
to one female in a lifetime, but judging from lifespan, sexually maturity,
and calving intervals - I am guessing they have, on average, between 5-13 calves.
The websites below may provide some more specific information.
Here are some great sites for more information about killer whales, Orcinus
orca:
Enchanted Learning
Orca On-Line
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Killer
Whale Mating
Q: I am interested in how
Killer Whales Mate and when the calfs leave their mothers in
the wild?
A:Orcas have rarely if ever
been observed mating in the wild. From what scientists do know
Orcas mate belly to belly in the water. The male and female Orcas
have their sexual organs located on their bellys (tucked away
in a slit) about midway down there bodies. The sexual organs
are tucked away a slit so the whales have less resistance while
swimming.
Orca's calfs never fully leave their mothers in the wild! Orca societies are
maternal (based around their mothers) and the calfs remain with their mothers
even after they are mature. On average a female Orca matures at about 15 years
and a male Orca matures at about 21 years and both of these are roughly accurate
with human maturation. In the wild the female Orca's live to be about 80 years
old while the males live to between 50-60 years.
Thanks for the great question.
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Killer
Whales living in Fresh Water
Q: I was wondering why Killer
Whales cannot live in freshwater?
A: Killer whales can survive
in fresh water but the marine environment is a much better home
for them. A salt-water environment is a much more stable than
freshwater environments are. This is important because the saltwater
stability makes it easier for a killer whale to live in saltwater.
Also the marine environment provides a stable temperature environment
unlike a freshwater one where there can be larger temperature
variations. The saltwater environment also provides a lot more
food than a freshwater one does. A lot of food is important for
a killer whale because they have to eat enough to support a body
weight from between 3000 to 12000 pounds! In other words they
have to eat a lot to maintain body weight. Also the salt water
environment is denser than freshwater and this allows for a greater
ability to float in saltwater.
Thanks for a great question.
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Are
Orca's Dolphins?
Are Orcs's Dolphins?
Q: I just bet a friend dinner
that Orca's are Dolphins and wanted to know whether this is true
or not.
A: The orca (Orcinus orca)
is from the Family Delphinidae which includes all the dolphin
and porpoise species. So yes the Orca is a dolphin. Usually it
is referred to as a whale because of their large size.
Thanks for the question.
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BELUGAS
Beluga
Songs
Q: Tell me about beluga
whales' songs.
A: According
to two U.S. biologists from their beluga studies in 1949, beluga
sounds are "high-pitched resonant whistles and squeals,
varied with ticking and clucking sounds - slightly reminiscent
of a string orchestra tuning up - as well as mewling and occasional
chirps. Sometimes, the calls would suggest a crowd of children
shouting in the distance. At other times, there were sharp retorts,
somewhat like a blow with a split bat or slap on the water."
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Endangered
Belugas? - Received from Hillary in Dundas, Ontario.
Q. I am doing a project on beluga whales I would like to know how can we save
them from extinction will there be any more left by the year 2020
AQUAFACTS BY VANCOUVER AQUARIUM
Q.Are belugas endangered?
A. Yes... and no... of eight Canadian beluga populations, three are endangered:
southeast Baffin Island (Northwest Territories), Ungava Bay (Quebec) and the
St. Lawrence River estuary (Quebec). Baffin and Ungava populations have about
1,000 individuals; the St. Lawrence population only 500. The St. Lawrence belugas
are affected by industrial pollution which is concentrated in the fish they
eat. For more information on the state of the Beluga population in the St.
Lawrence The
Ungava Bay and the southeast Baffin Island populations are still recovering
from commercial whaling.
- In some Arctic waters, belugas are potentially threatened by oil tanker and
ice-breaker traffic, and by hydro-electric development.
- There are approximately 50,000 to 70,000 belugas worldwide - the beluga is
the most abundant whale in Canadian waters!
As you can see, they are not currently in danger of extinction, but populations
in some areas have low numbers. If we continue to look after them, and especially
clean up their environment, there should be plenty of beluga whales around
in the year 2020. Beluga whales used to be hunted in large numbers, but now,
the only hunting that takes place is by Inuit hunters, and occurs only where
the population numbers are very large (not in the populations that are in trouble).
As you can see in the above AquaFacts article, the main threat to the St. Lawrence
Belugas is marine pollution. Who causes marine pollution? You do!!
You can help the Belugas most by making everyone aware that marine pollution
harms many types of animals. Remember: everything that goes down your sink
(or toilet - yuk!), or is put on your lawn, eventually makes its way to the
sea. Many industries that make the things that you buy every day pollute the
seas. If each of us does our part to stop pollution in our own back yards,
this will help to clean up the seas.
Tell your friends and family - become an advocate for clean water!!
Learn as much as you can about Beluga Whales, and marine biology, and let people
know what you've found out!!
Remember, even one person can make a difference!
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Green
Beluga -
received from Samantha in Connecticut
Q: Why dose
the Beluga look green at night?
A: To answer
your question, I'll need to explain a little bit about light.
Everything we see emits light, and that is why we see it. Light travels well
through air, so we usually get to see things quite clearly.
Water is clear when you look through little bits of it, but when you look through
lots it looks kind of green. This is because water absorbs some of the light
that passes through it.
Light is made up of different colours, and some colours of light can pass through
water better than others. Green and blue light can pass through water better
than red and orange, so the things that you look at through large amounts of
water tend to have a greenish tinge.
The white light coming off of a beluga and into your eye is composed of every
colour, but the greens and blues are more likely to make it all the way to
your eye than the reds and oranges. At night, the beluga isn't very well lit
up, so all you see is the green light.
Light is very fascinating!
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What
a Beluga Does in a Day
Q: Can you tell me about
what a Beluga Whale would do in a day?
A: What a beluga does in a
day, not only depends on where they live, but also what time
of the year it is. One thing most belugas would do in a day is
EAT! Belugas eat a wide variety of fish, shrimps and octopus.
Belugas use sound to find their food! They emit clicks from their
nasal passages. These clicks travel through water and bounce
off objects like ice, food or the ocean floor. Belugas listen
for the echoes of these clicks to determine where their food
is located. That is another thing belugas would do in a day,
sing. Well not sing songs like ones we would listen to, but belugas
communicate with a wide range of sounds: clicks, chirps, grunts,
squeals, screeches and whistles. Sound is an effective means
of communication for belugas because it travels long distances
through water. Belugas make such an array of sounds that nineteenth
century sailors and explorers of the high Arctic named them "sea
canaries". Belugas may also need to avoid predators. Killer
whales in the Arctic eat belugas, so belugas will hide under
ice patches avoid these hungry predators. In the summer and spring
an activity that would be included in a beluga day would be mating
and after 14 months a mother would give birth to a calf. These
are just a few things that a beluga may do in a day, but there
are still many things that we still do not know about belugas
and there is definitely a lot more research that needs to be
done. If you would like to know more about belugas I suggest
you check out the OceanLink website under the AquaFacts section
and check out the beluga whale page.
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Beluga
Whales - Received from Jonathan in Washington.
Q: I am doing a school report on Beluga Whales. I would appreciate a bit of
information to share with my 5th grade class. Here are a few questions: How
did the Beluga get its name? Can you teach Belugas tricks? Do you have some
Belugas in captivity, if so, what special types of care do you have to do for
them? Thank you. I appreciate this.
A. The
name "Beluga" comes from the Russian word for "white".
This sure makes sense, since these arctic whales are all white
in colour - in fact, their other name is "white whale".
The Vancouver Aquarium does
not teach the marine mammals there to do "tricks".
Instead, the focus of the programs at the aquarium is on public
education. The animals are encouraged to perform natural activities,
and the public is told why the animals do these activities, and
what it means for them in their natural habitats. Belugas are
very intelligent, however, and learn things very quickly.
There are five Belugas in
captivity at Vancouver Aquarium. Their names are: Aurora, Qila,
Allua, Kavna, Nanuq and Imaq. The water in the Arctic Exhibit
is kept at a chilly zero degrees Celsius (32 degrees F), just
like the water in the Arctic Ocean.
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Pollution
and Beluga whales
Q: How has oil and other types of pollution
affected Beluga whales?
A: Oil pollution will cause liver disease
and reproductive problems in spome spcies of bony fishes. It
is possible that this can affect Beluga whales as well. Oil pollution
does have other effects on whales however. Oil will often kill
many other organisms and this will affect the food chain. If
the Beluga's food source is killed by oil pollution the Beluga
will be in serious trouble. Most world oil pollution is from
natural sources, routine machinery maintenance and from people
pouring engine oil down the drain rather than dispose of it properly.
Other types of pollution that negatively affect Beluga whales are heavy metals
poisoning and PCB's (Polychlorinated Biphenyls). Heavy metals can cause birth
defects in whales and nervous system damage while PCB's can cause reproductive
troubles in whales. The Beluga whales of the Saint Lawrence in Canada are dying
from metals and PCB's more than from oil pollution.
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NARWALS
Narwhals
- Received by Anisa in Sydney, Australia.
Q: I am mentoring a year
5 child researching narwhals as her major project. She is writing
it in a journal format, as a scientist studying narwhals, and
so needs to ask someone who has been in the field, as she is
to write about those experiences. If you can answer these questions,
we are grateful.
While I have never personally
been in the field studying narwhals, I'm more than happy to answer
your questions as best I can.
1. What is the estimated
population of narwhals and where are they located?
Narwhals (Monodon
monoceros) have a discontinuous circumpolar range primarily above
the Arctic Circle, and they are rarely found south of 70 N. Their
population is estimated to be between 25,000 to 45,000 individuals.
2. Has global warming affected
their migration patterns, and if so, how?
Narwhals migrate northward
in the spring and southward in the fall, travelling in groups of
up to 2,000 individuals. I'm unaware of any recent studies pointing
to a change in migratory patterns in relation to global warming,
although I imagine that if there were changes in ocean temperatures
which affected the range of species narwhals prey on, the whales
might be required to alter their migration accordingly.
3. Are narwhals known to
be friendly towards humans?
The narwhal's predators
include killer whales, walruses, sharks and polar bears. However,
its main predators are humans. Narwhals are hunted primarily by Inuits
both in Canada and Greenland for their tusk, skin, meat and blubber.
I would imagine that narwhals are therefore rather wary of humans
and might not approach them freely.
4. Is it suitable to dive
with them for documentary purposes, and when is the best time
of year?
Marine scientists
and photographers have SCUBA dived with narwhals and documented their
behaviour. The best time of year to observe narwhals in this manner
would likely be in the summer, when weather conditions are favourable.
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Narwhal
Info - Received from Isabella in Sydney, Australia
Q: Can't find anything
on narwhal. Thank you. (her Dad typed this for her, she is
4)
A. The Narwhal (Monodon
monoceros) is closely related to the beluga whale, and
both are in the family of whales known as the Monodontidae.
These gregarious whales are common in subarctic and arctic
waters, where they feed on a variety of fish species, squid
and shrimp.
The Narwhal is usually greyish-white
in colour, with dark mottling of the back and sides. These whales
lack a dorsal fin, which is replaced by a distinct hump. The
animals have a bulbous forehead, a slight beak, and short, upcurled
flippers. The Narwhal has an unusually shaped fluke with convex
trailing edges. The male has a long spiralling tusk (like the
fabled unicorn) which is actually a modified tooth, and is used
like the antlers of deer in fights over females and a visual
display of strength. Female Narwhals do not have tusks, and can
be almost completely white in colour. For this reason, female
Narwhals are often mistaken as Belugas.
During feeding, the whales
spend little time at the surface, usually diving for periods
up to 20 minutes. Members of a group may surface and dive at
the same time. These whales have been seen spyhopping, lobtailing
and flipper-slapping, but rarely breaching. The Narwhal blow
is fairly weak and inconspicuous.
Predators of Narwhals include
killer whales, walruses, polar bears and sharks. However, these
whales have also been traditionally hunted by the Inuit for its
valuable tusk and its thick skin.
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Narwhal's
horn - received from Branden in New York
Q: What is a narwhal's horn
made out of?
A: The horn of a male narwhal
is actually one of it's two teeth. The left tooth usually grows
into the long twisted tusk, while the right tooth remains within
the gums. Female narwhals have two teeth as well, but they don't
grow out past the gums. Some male narwhals hae been found with
two tusks, in the case of both their teeth growing out.
I found this info in Eyewitness Books: Whale, by Vassili Papastavrou.
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Narwhal
relationships -
received from Karolina in Sweden
Q: I wonder if you know:
How is the relationships between the whales in a narwhal stock?
A: That is great question!
Narwhal's (Monodon monoceros) travel in groups of 3 or 4 or
up to 10 whales. During the breeding season they have been
observed in large groups of up to 20 or 50 males showing "fencing" exercises.
Fencing is a sexual display put on by males to compete for
females. The size of tusks (often used in violent battles)
will define the hierarchical status of males in a group. During
migrations groups are often segregated by sex and age. the
following groups have been observed travelling together:
1.immature males
2.mature females and calves
3.large adult females
These groups will generally hunt and feed together, often diving and surfacing
at the same time.
Here are some websites with info on narwhals:
Enchanted Learning
Thinkquest.org
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Narwhal
Tusks
Q: If only male Narwhals have
tusks how do females break through the ice to breathe?
A: Narwhals do not appear
to use their tusks for breaking the ice. Biologists believe that
the male Narwhal uses the tusk for fighting with other males
for mating rights with females. Narwhals with larger tusks may
have a better chance at mating with a female. For the most part
Narwhals keep breathing holes open by simply using them a lot
and preventing them from freezing up.
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TOOTHED WHALES
Baird's
beaked whale - Received from Stephanie on Parris Island.
Q: Can you tell me anything
about the bairds beaked whale? We are studing this in my fourth
grade class.
A: Beaked
whales are classified in the Family Ziphiidae, and are the least
known of all cetaceans (whales, dolphins and porpoises). Some
species of beaked whales have never been seen alive and are known
only from dead specimens which have washed ashore. One of the
reasons that Ziphiids are so elusive is that they live far from
shore in very deep water. The most distinguishing characteristic
of beaked whales is the presence of tusk-like teeth on the lower
jaw of male animals (often females do not have teeth). There
are 20 known species of beaked whales, although it is possible
that there are others yet to be discovered.
Baird's beaked whale (Berardius
bairdii) is thought to be the largest of all beaked whales,
with adults measuring between 11-13 m (35-42 ft) in length
and newborns estimated at 4.5 m (15 ft) in length. Both male
and female B. bairdii have two pairs of teeth, with
the front pair protruding out of the dolphin-like beak. Baird's
beaked whales have a prominent bulbous forehead, small dorsal
fin, small and rounded flippers, and a long, spindle-shaped
body. Adults are usually greyish in colouration and males often
display heavy scarring on their dorsal surface (upper side),
likely due to fights with other males.
B. bairdii is
found in deep temperate and subarctic waters in the north Pacific
Ocean. When observed on the surface, they are found in a tightly
organized group of 10-30 animals. They are usually visible for
less than 5 minutes, after which they dive for approximately
25-35 minutes. These whales are known to congregate in offshore
waters at least 1000 m (3300 ft) deep, and they rarely enter
shallower waters.
For more information on these
cetaceans see the
Beaked Whale Resource page.
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Sperm
Whales - Receiver from Emma in New Jersey
Q: Where did Sperm Whales
get their name? What do Sperm Whales eat? and where do they
live? Do Sperm whales Migrate?
A: The adjectival noun Sperm
in the common name that refers to the spermaceti or sperm oil
obtained from the animal's head, although some have suggested
that it may refer to the large size of the male's retractable
penis (approximately 2m). The latin name for of the Sperm whale
in the Northwest Pacific is Physeter macrocephalus. Physeter is
a Greek word meaning "blower," and refers to the whale's
behaviour of making a vapor spout when it exhales air from its
lungs at the surface. "Macro" means large and "cepahlus" means
head, therefore "macrocephalus" means large head.
Sperm whales feed mainly on
squid but also eat octopus and a variety fish such as salmon,
rockfish and skates, some which are found at depths as great
as 1,500 feet to perhaps 2 miles. The average male will consume
up to 3.5 percent of it's body weight in squid. Sperm whales
are found throughout the deep waters of the world's oceans, from
the equator to the polar seas. Sperm whales do migrate from their
breeding grounds and feeding grounds. To find out more information
on sperm whales I suggest you check out this website and search
for information on sperm whales, I am sure you will find more
information there!
Animal Diversity at University of Michigan
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Ambergris
in Sperm Whales - from Raul M. Orozco in Ontario,
California, United States
Q: I know that ambergris
is produced in the Sperm Whale's intestines. However I would
like to know how it is extracted? Or does the whale dispose
of it by vomiting or by a bowel movement?
A: Yes, ambergris is produced
in the large intestine of only sperm whales, but only occurs
in 1-5% of the animals and how it is formed is unknown. Ambergris
is round-shaped, usually weighs between 0.1-10.0 kg, but some
have weighed as much as several hundred kilograms! It is mainly
composed of an ester of ambreine (a non-volatile, high molecular
weight alcohol) and usually contains chitinous cephalopod beaks.
Finally, to answer your question ambergris is passed through
with the feces and also extracted in autopsies of dead sperm
whales.
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Giant
squid vs. sperm whale - Received from Mrs. Dello Russo's
class in Cambridge, MA
Q: In a battle between
a giant squid and a sperm whale, who wins and why? How can
scientists tell is the scars on a sperm whale's body are from
fights with a giant squid on the bottom of the ocean?
A: In battles between sperm
whales and giant squid, it's hard to tell who wins all the time.
Considering giant squids have been found in the stomachs of sperm
whales, and that sucker scars are often found on these whales,
chances are the whales win a lot of the time. However, if a giant
squid won, we'd really have no way of knowing because the whale's
body would sink to the bottom of the sea.
Scientists can tell if the
scars on sperm whales are from giant squid by comparing them
to the suckers found in the stomachs of whales, and from squid
washed up on beaches. The scars would tend to be pretty near
circular and have serrated cut from the teeth in the suckers.
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Whale
or dolphin? - received
from Kevin in Washington.
Q: Is a Killer Whale related
to a dolphin or is it really classified as a whale?
A: Killer whales (and five
other small toothed whales, known as "blackfish") are
classified in the family delphinidae, which also includes 26
species of dolphins. The blackfish are generally considered more
related to dolphins than to other whale species, even know they
are quite unlike dolphins in appearance.
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Blackfish
Q: While fishing yesterday I saw a
large jet black animal in the ocean with a curved dorsal fin.
The locals called it a blackfish but I could not find any information
on this generic name. Any idea what I saw?
A: Blackfish is the generic name to
describe a group of smaller toothed whales. These whales include
species such as the Killer whales, the false killer whales, the
pilot whales, melon headed whales and so forth. These whales
are from the family Delphinidae that includes all of the oceanic
dolphins.
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