Hervey Bay, Queensland, Australia, 1990 |
Each year humpback
whales migrate long distances from polar waters near ice zones to tropical
winter breeding grounds near islands and bank areas. They tend to prefer
breeding waters 25 degrees C, quiet bays and leeward sides of exposed reefs
with depth of 200 m. or less, and large banks wider than 3-5 km. Research
indicates that the whales may use acoustical orientation and sensitivity
to water and temperature currents or even rely on changes in the earth's
magnetic field to "home in" on their breeding and feding grounds.
Whatever their secret of pathfinding, humpbacks reguarly appear in Australian
waters in June. they don't arrive en masse but flow in and out
over a five mont period. The fact that humpbacks swim south in October and north in may in both hemispheres assures the northern and southern populations do not intermingle. Even where both populations use the same equatorial waters (10 degrees north), they are never there at the same time. |
The Humpback whale (Megaptera novaeangliae) is the
fifth largest of the great whales. The females are slightly larger than
the males in the adult stage, reaching 15 m. and 14 m. in length, respectively.
A mature humpback may weigh up to 2,7 tonnes/m., or nearly 36 tonnes (36,000
kg) when fully mature. Calves range from 4 to 6 m. in length and average
1,35 tonnes (1,350 kg) at birth.
The Humpback whale is an endangered species that has been protected from whaling since 1963 in the Southern Hemisphere. The east Australian stock is estimated to be in the order of 1,200 animals and the west Australian stock, 1,400 animals. Both groups arte believed to winter in different aras of Antarctic, although some limited exchange may occur between the two groups. |
The likelihood of seeing a whale decreases with increases in sea states, wind speed, sun glare, or other conditions which may hamper visibility. Midday is the preferred time to observs whles from land or air, since the sun is almost deirectely overhead. From a boat whalewatching is more dependent upon weather and less influenced by the time of day. |
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SPY HOP: The whale rises relatively straight up out of the water rather slowely, maintains its head above the surface to just below the eye, often turns 90-180 degrees on its longitudinal axis, then slips back below the surface. |
Whether you use an instamatic camera or one more sophisticaded, there arew several basic rules to follow when attempting t photograph whales. Hold your camera steady. Make ceartain that the horizon line is level in your viewfinder. Slowly depress the shutter release. Never follow the whale through it's movements while taking a picture as this will blur the image. Set your shutter speedfor at least 500th of a second; this will freeze the movement of the whale, the boat, the ocean and your body. When using a camera with a light meter, set the correct aperture by aiming your camera on the water in the direction of the whale, not on the sky and the water. This will give the proper color balance for the whale and the water, with the sky slightly over-exposed. |
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