 |
|
|
|
|
|
Which species of Whales & Dolphins
can I see in Oman? |
|
|
|
To find out more click here... |
|
|
|
|
|
Are Dolphins Fish? |
|
|
Despite the fact that they live in the ocean, dolphins are
warm-blooded mammals that breathe air and suckle their
young.
They seem to have arisen from a family of hoofed land
mammals, of which the dog-sized Mesonyx is an example. |
|
|
|
|
|
What is the difference between
dolphins and whales? |
|
|
|
There is a difference between what we call a whale and what
biologically is a whale. We tend to use whale for larger
mammals living in the sea. Biologically, however, whales
have baleen whereas dolphins have teeth. Killer whales for
instance therefore are technically dolphins. |
|
|
|
|
|
What do they eat? |
|
|
|
Dolphins feed on most kinds of fish, including mullet,
whiting, snapper, tuna, bream and invertebrates such as
squid. |
 |
|
|
|
How do they sleep? |
|
|
|
Dolphins sleep on the surface with only the blowhole
exposed. Dolphins are 'conscious' breathers, which means
that they have to be awake or semi-conscious to breathe,
otherwise, they would drown. They doze for a few minutes at
a time, and their blowhole periodically opens and closes by
reflex action. They sleep in a semi-conscious state, resting
one side of the brain for a short time then swapping over.
This technique also allows them to be aware of any dangers. |
|
|
|
|
|
How deep can dolphins dive? |
|
|
|
Bottlenose dolphins can dive to depths of 21 metres and even
to 30 meters. Risso's dolphins can dive to over 1000 meters. |
|
|
|
|
|
Why do they jump? |
|
|
|
There are four probable reasons that dolphins jump: either
to play, for communication with other dolphins, to get rid
of parasites, or to get a better view over the water. |
|
|
|
|
|
Do they migrate? |
|
|
|
Some species of dolphins migrate. Some species travel
hundreds of kilometres over a roughly circular territory,
most probably due to food sources. |
|
|
|
|
|
What is their gestation period? |
|
|
|
Gestation lasts for 10 to 12 months. |
|
|
|
|
|
How long do calves stay with their
mothers? |
|
|
|
Calves can stay with their mothers for up to five years or
longer. Mothers are very protective and keep the calf at
their side at all times during this period. |
 |
|
|
|
What do their sounds mean? |
|
|
|
Dolphins use sound (i.e. sonar or echo-location) to find
objects and hunt for fish. These sounds are high frequency
are may be sent out at a rate of several hundred per second.
The sounds bounce off objects in the water and are picked up
by special tissue in the lower jaw of the dolphin which
conducts the echo through to the inner ear. This allows
dolphins to identify objects without having to touch them.
Dolphins also sometimes use their sonar to stun fish. They
also use sound to communicate with one another. |
|
|
|
A Dolphin Echolocates |
|
|
|
 |
|
|
|
|
|
How long can dolphins stay under
water? |
|
|
|
For periods of up to 1 hour, although five minutes is
usually the average. |
|
|
|
|
|
Do dolphins look after their sick? |
|
|
|
They are famous for doing so, although this behaviour has
rarely been observed in the wild. Dolphins stay underneath
and at the sides of the sick and by doing so keep them close
to the surface so that they can breathe. They do give up
after some time though. Dolphins also have been observed
swimming away from another dolphin entangled in a net. They
might therefore have the ability to discriminate between
situations, in which an attempt to save another dolphin's
life poses a threat to their own life and situations in
which that is not the case. |
 |
|
|
|
How intelligent are dolphins? |
|
|
|
Since no one has come up with a method to successfully rate
the intelligence of a human being, measuring the
intelligence of other species has proven difficult if not
impossible. The evaluation of dolphins' intelligence is
especially difficult, because they are adjusted to an
entirely different medium, ie. water. However, we can say
that dolphins are fast learners and are able to generalize
and to learn sign systems. |
|
|
|
|
|
Are whales local or migratory? |
|
|
|
Most whales are migratory and travel to the poles in the
summer and back to warm temperate waters in winter. Some
populations are resident though. |
|
|
|
|
|
Are whales and dolphins happy in
captivity? |
|
|
|
No, not at all. Wild dolphins and whales reach ages well
above 30 years. In captivity, however, the average age for
dolphins is 6 years. They tend to develop disturbed
behavioural patterns too. Some countries, for example
Britain have given up on keeping dolphins in zoos. |
|
|
|
|
|
Can you feed dolphins and whales? |
|
|
|
No, you should not. Feeding them will change their feeding
behaviour and will have a detrimental effect on the marine
life in general. If you feed dolphins or whales, you
interrupt the natural food chain. How long is the gestation
period for whales? It is between 10 to 13 months. Whales
give birth to a calf every 2 to 3 years. |
|
|
|
|
|
Can whales and dolphins communicate
across species? |
|
|
|
They understand basic elements of other dolphin or whale
species behaviour, some to the extent that they interbreed
like rough toothed and bottlenose dolphins. |
|
|
|
|
|
How long is their lactation period? |
|
|
|
The calf is breast fed for 3 to 9 months. |
 |
|
|
|
How many calves do whales have? |
|
|
|
Whales gives birth to one calf at a time. |
|
|
|
|
|
How long do whales stay underwater? |
|
|
|
They mostly stay underwater for short periods of time like 3
to 8 minutes. However, longer periods of up to 30 minutes
have been recorded. |
|
|
|
|
|
Are whales and dolphins aggressive
and dangerous? |
|
|
|
Most dolphin and whale species are peaceful and rather shy.
So far humans have proven to be of much greater danger to
whales and dolphins than the other way round. However, some
species like killer whales and pygmy killer whales can
become aggressive. They are much less aggressive than their
names imply though. If you go diving with whales, the danger
is mostly a result of their size. They might harm you
without intending to do so. |
|
|
|
|
|
Why do whales strand? |
|
|
|
There are different theories on this issue. The most recent
evidence suggests that whales strand if their hearing is
impaired by loud noise which can be caused be the Navy's
sonar systems for instance. |
|
|
|
|
|
Why are killer whales called killer
whales? |
|
|
|
They are called killer whales due to the fact that feed
largely on warm blooded prey. They hunt down whales
occasionally, therefore the name "killer (of) whales". |
|
|
|
Why are sperm whales called sperm
whales? |
|
|
|
Sperm whales were hunted for spermacetes, a substance found
in their heads which was used to the production of perfumes,
candles and ointments. |
 |
|
|
|
How well do whales and dolphins
hear and see under water? |
|
|
|
Whales and dolphins hear very well underwater, though not in
air. A human being's hearing ranges from 40 Hz to 20 kHz.
Dolphins use very high sounds for echolocation, so they can
hear sounds as high as 150 kHz. Low sounds travel very far
underwater, so whales can hear up to 20 Hz. Their sight,
however, is not very good, because it is not very important
to them underwater. In deeper waters there is darkness,
because light waves donŐt travel very far into water.
Dolphins and whales therefore navigate by their hearing
instead of their sight. |
|
|
|
|
|
How can I distinguish a male whale
from a female? |
|
|
|
At sea it is difficult to distinguish the two. In the baleen
whales, females tend to be larger than males. In the toothed
whales males tend to be larger. They might also have other
distinguishing features such as larger melons, larger dorsal
fins or distinctive teeth. the genital organs are internal
for both sexes. However, the genital sex is located midway
between naval and anus in males and farther back, joined
with the anal slit, in females. |
|
|
|
|
|
Whale and Dolphin Watching
Guidelines |
|
|
 |
Do's:
Let the whales or dolphins choose how they will interact
with you.
Slow down to a "no wake" speed 300m from whales or
dolphins.
Approach from a position parallel and slightly behind.
Limit your approach to 100m for whales and 50m for
dolphins.
If the whales or dolphins approach closer, turn off your
engine and let the motor idle.
Maintain a predictable course of speed. |
|
|
Don'ts:
Speed through groups of Whales or Dolphins.
Seperate groups (particularly groups with young).
Block their direction or travel or attempt to herd them in
any way.
Throw rubbish in the water or attempt to feed them.
Chase animals if they are clearly trying to avoid the boat
or leave the area. |
|
|
 |
|
|
|
|