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| 50 Owen St, Huskisson NSW 2540, Australia. Ph: 02 4441 6311 Fax 02 4441 5885 |
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Distinguishing features
Very long flippers (pectoral fins) which are mottled on
the upper surface and white underneath. The flippers are
about one-third of the body length. Fleshy, knoblike swellings
(tubercles) on head and lower jaw. |
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Social Unit
At their breeding -grounds, humpbacks generally congregate
in small groups but in the colder waters where they
feed, they have been observed in large groups. During
migration between the breeding and feeding grounds,
humpbacks usually travel alone or in small groups scattered
over a wide area. The newborn calf travels with its
mother until it is weaned. |
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Length
Adults up to 15m. Females grow larger than males. At birth
about 4.5m; at weaning (I year old) 8.5m. |
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Weight
Average adult 40,000 kg, maximum 48,000 kg. Calves weigh
about 1,300 kg at birth |
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Profile
Rotund body with the dorsal fin about two-thirds of the
way back along the body. Broad tail (flukes)
rippled on the rear margin. The flippers are scalloped
on the front margin. About thirty pleats extend from the
chin to the navel. Barnacles and whale lice are commonly
found on humpbacks. |
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Markings
Basically black or grey on the upper surface, with a mottled
black and white area on the throat, flanks and belly.
The tail has a dark upper surface but the under side is
a variable pattern of black and white plus scars of all
shapes and sizes. This pattern is visible when the whale
raises its tail just before a dive. Each whale has a unique
pattern, and photographs of the pattern are used to identify
individuals. Many whales are sighted again and again but
there are always new ones passing along our coastline
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Vocalisations
The underwater sounds of the hump-back include grunts,
groans, moos, cries, brays, whistles, rasps and twitters.
Adult males are very vocal, and because their vocalisations
have a formal structure they are called songs. For some
time it was thought the adult males only sang when they
were at the breeding grounds in tropical waters. But researchers
have recorded humpbacks singing at Jervis Bay and Eden.
Humpback songs are long and complex; all phrases are repeated
in the same sequence by each whale. Each year the song
changes slightly from the previous year. |
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Surface Behaviour
Of all the large whales, the humpback is the most acrobatic
and whale watchers use the following words to describe
each action:
- Breaching: leaping clear of the water and spinning
- Lobtailing: raising the tail and then crashing it
down
- Spyhopping: poking the head above the water
- Flipper slapping: raising a flipper and slapping
it on the water
- Waving: lying on its back waving both flippers in
the air.
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Diving
When the humpback starts a long dive, it will arch its
back and raise the tail high into the air. As soon as
the whale returns to the surface it will blow (a cloud
of vapour produced by condensation when the whale exhales).
The shape of the humpback's blow is distinct: a balloon
of spray up to 3m tall. |
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Feeding
Instead of teeth, the humpback whale has baleen which it uses
to catch its prey. There are up to 800 baleen plates rooted
in the top jaw, and' the largest plate is 65 cm, long. The baleen
is constructed of material much like fingernails and claws.
The outer edge of the baleen is smooth, and the inner edge is
covered with bristles which intertwine to form a sieve. To feed,
the whale gulps a huge mouthful of water containing krill (shrimplike
crustaceans) and small fish. The mouth is then closed, forcing
the water out through the baleen plates, and the food is trapped
in the bristles on the inside of the baleen. The humpback is
a seasonal feeder, consuming huge quantities of food during
summer; for the rest of the year it mainly lives on reserves
of body fat. |
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Distribution and Migration
During winter humpbacks are concentrated in their breeding
grounds-tropical waters, often near the coast and around islands.
In early spring they leave the warm waters and travel thousands
of kilometres to their summer feeding grounds-the krill-rich,
polar waters. At the end of summer, humpbacks head back to their
breeding grounds. |
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| Limits of Approach to Whales |
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Strict regulations govern
approaches to whales and the law provides heavy penalties
for disturbing or harrassing them.
Swimmers and divers
- Do not approach closer than 30metres.
Powered and unpowered vessels (including surfboards)
- Must never approach closer than 10Ometres. Jetskis(PWCs)
must never approach closer than 300 metres
- If a whale is accompanied by calf do not approach closer
than 200 metres
- Within 300 metres of a while' (400 metres for jetskis)
move at a constant speed no faster than the slowest whale
or at idle 'no wake' speed
- Approach from a direction parallel to the direction of
movement of the whales and slightly to their rear
- Avoid sudden or repeated changes in speed or direction
- When stopping to watch whales either place your engines
in neutral or allow the motor to idle for one minute before
switching off
- No more than three vessels should attempt to watch a whale
or whales at one time
- Do not 'box' whales in, cutoff their path, or prevent
them from leaving
- When leaving whales, move off slowly at 'no wake' speed
until at least 300 metres away (400 metres for jetskis).
Aircraft
- Fixed-wing aircraft, including ultralights and hang gliders,
MUST not be flown closer than 300 metres (approx 1,000 ft)
above or near a whale
- Helicopters must not be flown closer, than 400 metres
(approx 1,300 ft) above or near a whale.
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| Information on the Humpback whale from NSW National Parks
and Wildlife Service and Organisation for the Rescue & Research of Cetaceans
in Australia |
| "Free return cruise if no dolphins are sighted
on a dolphin cruise" |
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| 50 Owen St, Huskisson
NSW 2540, Australia. Ph: 02 4441 6311 Fax 02 4441 5885 |
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