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The power and efficiency of the killer whale predator can be fully appreciated when porpoising out of the water.
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Photo : Chris Johnson |
May 6, 2004
A 'Killer' Visit
Real Audio Report
28k
Log Transcript
Most days onboard Odyssey start out the same way, but then something unbelievable happens. Suddenly you know today is a day you will remember for the rest of your life.
At 10am this morning, the wind speed picked up, the whitecaps steadily increased in size and number and the swells moved to the north with greater energy. At 11 am, Chris called down from observation watch - "I see several blows off the port bow at 2,000 meters."
Captain Mark Preedy turned Odyssey 10 degrees, Ildiko continued to call direction and bearing from the observation platform and the rest of the crew scurried up from below, spilling out onto the deck. We were six miles off the coast of Eritrea in 30 meters of water. We followed the blows through binoculars, eager to identify the species. Then a towering black dorsal fin rose from beneath the crest of a wave - it was a group of killer whales (Orcinus orca).
There now appears to be more than one type of killer whale, in fact genetic studies are revealing the possibility of several types. It was likely this group was a family of transients, the marine mammal eating type, as opposed to residents the fish eating type. Transient groups tend to be smaller in number than resident groups, reflecting their specialization in cooperative foraging on marine mammals. Killer whales are the only cetacean species that routinely prey upon other marine mammals ranging from seals and sea lions, to porpoises, dolphins and sperm whales and even the largest baleen whales. To date, over 35 different marine mammal species are recorded as being attacked by killer whales.
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Exuberant leaps reveal the black and white tuxedo that makes this the most widely recognized toothed whale in the world.
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Photo : Chris Johnson |
The group traveled in the same direction as Odyssey at four knots. At 400 meters, the whales turned, ploughing through the waves directly toward us with a boldness and confidence reserved only for apex predators.
Within seconds, they were upon us. We counted six animals. The first impression was vivid, an immense set of black dorsal fins and white eye patches, the only visible clue to the three and four ton mammals below. The adult male was enormous, his towering dorsal wobbled like rubber without the support of water. A mother and calf pair swerved by on their sides rolling beneath the bow in unison - the calf trailing something indiscernible from its mouth, perhaps food or maybe it was playing with a mat of seaweed. It was impossible to determine the sex of the other three - adult females or sub-adult males, most likely a combination of both.
Their curiosity temporarily satisfied, they dove and surfaced moments later almost 300 meters off our stern and heading away from Odyssey. We turned and followed the group, desperately hoping they were interested enough to make another pass by us. They continued on their course at a distance and submerged, we thought the encounter was over.
The crew was all on deck, scanning in every direction. Suddenly, a whale exploded through the surface only meters away, a white belly and black back hanging suspended against a blue sky - we were breathless. Next the mother and calf surfaced at our beam, the adult male only a few meters beyond them. The group had circled back to join us.
While most of the crew watched and called directions from the bow, Mark yelled from the pilothouse door "There are whales right next to the boat" The mother and calf were swimming so close to us, Mark could have leaned over and touched them. The crew lined up along the railing on the starboard beam. We could see the whales only inches below the surface hugging the hull - they were catching a free ride by drafting Odyssey.
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This adult male uses his two meter pectoral flipper to slap the sea surface. Mature males develop disproportionately larger appendages than females, although scientists are unsure why.
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Photo : Chris Johnson |
Our attention moved from the whales at our beam to an animal porpoising out of the water five meters off our stern. We stared at the whale in disbelief; you don't see a four-ton predator coming at you head on everyday. The girth of the robust, muscular body was striking, a black and white torpedo with two oval pectoral flippers flung out on either side. The re-entry caused a splash large enough to soak the aft deck. It is only at close range, and fully clear of the water that one is able to fathom the awesome strength, size and grace of these marine mammals.
Killer whales are anatomically similar to smaller dolphins and are the largest, most dramatic species in the dolphin family (Delphinidae). Killer whales are one of the oldest Delphinids, branching off from the main evolutionary group comparatively early. Over time, most Delphinids diversified from the basic plan, each genera developing specialized adaptations. Killer whales in comparison underwent fewer refinements to the general type, specializing in a large body size to exploit large prey. Their simple counter-shading is believed to be the most primitive within the dolphin family.
We were surrounded - the whales porpoised and breached on both sides of Odyssey. Their exuberant leaps revealed the black and white tuxedo that makes this species the most recognized in the world. The group continued to travel with us. The adult male barrel-rolled several times before stopping mid-roll with belly facing skyward and starting slapping a huge pectoral flipper against the surface, the two-meter paddle hitting the water with a crack.
Mature males develop disproportionately larger appendages than females, including wide tail flukes, a tall dorsal fin and rounded, paddle shaped pectoral flippers. Scientist are unsure of the reason behind a phenomenon that does not occur to the same extent in any other dolphin species.
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Close social bonds unite killer whale society and are often made up of several generations.
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Photo : Chris Johnson |
An animal spy-hopped next to the male, rising vertically through the surface revealing a blunt snout and rounded black head. It sunk back beneath the green water and followed up with a breath-taking sequence of breaches. A third animal burst through the swell breaching on its back and exposing its porcelain white belly. On the other side of Odyssey, the mother and calf were tail-slapping.
The crew was stunned - it was as though the whales were showing us what they could do. We were completely absorbed for what seemed like an eternity, but in reality was only five minutes. The whales moved beside us with such ease and confidence - two warm-blooded, air-breathing mammal species, sharing a few brief moments. Killer whales like humans have risen to the top of the food chain and are adaptable to a variety of habitats; they have a long life span, and live in highly social cooperative groups organized by complex vocal repertoires. The Killer whale is second only to humans as the most widely distributed mammal on earth and has no natural predators other than humans.
Killer whales are most commonly found off the continental shelf in the cooler waters of the north and south poles where productivity is highest. One is less likely to encounter them in the tropics where productivity is lower. Very little is known of their movements on a global scale and there is no reliable population estimate. Each observation in the wild is highly valuable and enriches our understanding of these unique marine mammals.
For the crew of the Odyssey, these five minutes were a highlight of the expedition so far. This is Genevieve Johnson speaking to you from Eritrea, on the southeast coast of the Red Sea.
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A Killer whale tail-slaps.
The trailing edge of the flukes are marked by notches and scars that assist in identification of individuals.
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Photo : Chris Johnson |
Links:
Log written by Genevieve Johnson.
