The Great Migration
The Great Migration
By T.C.Evamay
This month, my letter from Hawaii is posted from England where I had the privilege of watching David Attenborough’s documentary entitled, ‘The Great Migration,’ in which he describes, with his typical eloquent and knowledgeable manner, the journey of the wildebeests in Africa I know that many of you would have watched this also. However, another great migration came to my mind; a journey just as perilous but so much longer and of which I am often reminded when I gaze seaward from my home in Hakalau on the east coast of the ‘Big Island’ of Hawaii. Each year Humpback Whales make the journey from Hawaii and back again; a feat no less incredible than that of the wildebeests and it inspired me to write my letter on this occasion, not so much about the migration, but about the mighty humpback whale itself. Nothing to do with England of course, but in Hawaii the humpback is the centre of attention for tourists and marine biologists alike.
With a graceful splendor this 50’ giant glides effortlessly through the depths. With few natural predators, the humpback whale roams the oceans of the world with almost total impunity. During the fall, it will begin its migration from the rich but icy cold feeding grounds off the Alaskan coast to the warm tropical seas around the equator. Some make the annual pilgrimage to Baja Mexico, while others travel to a small group of islands just south east of Japan. In the main however, almost 70% of north Pacific humpbacks power their great bulk gracefully across 3,500 miles of ocean to the warm waters surrounding Hawaii. There is a definite pattern to the migration with juveniles usually arriving in Hawaiian waters first, followed by adult males, adult females, and finally the pregnant females, who feed for as long as possible to build up reserves enough for them and there unborn calves. The majority of humpbacks settle in the waters off Maui, however, they can be seen from most vantage points around the islands and as I watch them from my home in Hakalau, I can say with confidence, that there is nothing more exhilarating than watching a humpback breach.
The thrill of watching this monster breach is unrivalled.
Relatively speaking… if the humpback had teeth, we would be easy meat. Humpbacks feed only in summer and live off their fat reserves in winter. The long arctic days bring many hours of sunshine and therefore photosynthesis which creates nutrients in the waters for krill and small schooling fish feed upon. The Humpback employs several methods to hunt its prey, but perhaps the most inventive and impressive technique is known as ‘bubble net fishing.’ A group of whales swim in circles and blow bubbles to create a ring of bubbles around schooling fish. The ring encircles the fish, which are confined in an ever-decreasing area as the whales swim in smaller and smaller circles.
The "bubble net" encircles its catch.
Suddenly, the humpbacks, mouths wide open, will swim upward through the bubble net and swallow thousands of fish in one gulp. This species of whale is a ‘baleen,’ which means it has no teeth. Instead, a protein substance called keratin (which incidentally makes up human hair and fingernails), creates approximately 335 baleen plates totaling 2 to 2 1/2 feet in length.These plates hang vertically from the whale’s upper jaw. The whale filters its food by straining water out through its baleen with its tongue. This allows the whale to gulp between 500 and 1000 gallons of water along with 40 to 50 lbs. of food in one mouthful. It can consume approximately one ton of food per day.
Lunging through the bubble net… Yummy! The tropical waters of Hawaii are too warm and nutrient free (which is why our waters are so clear & blue) to support the quantity of the humpback's food sources to sustain them year round. For this reason, after they have given birth and weaned their calves, they must migrate back to the colder northern waters to feed and rebuild their blubber supply. The humpback has few predators; Orcas, some species of sharks, and humans. Individually, although faster, Orcas lack the size and stamina to be successful in an attack against its larger cousin, however, on occasion they will group together into a pack and maintain a sustained attack – which often last for days at a time. A healthy adult humpback will survive such an attack, but juveniles and the infirmed usually succumb to exhaustion. Approximately 20% of all humpbacks have battle scars depicting survival from the angry teeth of battle. On rare occasion, a sick and dying animal might be attacked by some species of sharks, but normally healthy individuals will have nothing to fear from these formidable creatures on a day-to-day basis. By far the biggest predator to worry the humpback is human. A target for the whaling industry throughout the 19th and early 20th centuries, the humpback whale was hunted almost to extinction until in 1966 a whaling moratorium was introduced and the species has since recovered to a worldwide population of 80,000. Humans still remain the biggest danger to these giants of the sea however, as they are still hunted under the guise of ‘scientific research.’ Humans are also responsible for other major causes of humpback deaths… entanglement in fishing gear; collision with ships; noise pollution and underwater electronic warfare are but to mention a few which remain major threats to the survival of the humpback whale to this day. The Humpback Whale is truly a magnificent creature; a gentle giant; a ballet dancer of the deep. The world would be the worse without them and I consider myself privileged to be able to share my home with them.
By T.C.Evamay
This month, my letter from Hawaii is posted from England where I had the privilege of watching David Attenborough’s documentary entitled, ‘The Great Migration,’ in which he describes, with his typical eloquent and knowledgeable manner, the journey of the wildebeests in Africa I know that many of you would have watched this also. However, another great migration came to my mind; a journey just as perilous but so much longer and of which I am often reminded when I gaze seaward from my home in Hakalau on the east coast of the ‘Big Island’ of Hawaii. Each year Humpback Whales make the journey from Hawaii and back again; a feat no less incredible than that of the wildebeests and it inspired me to write my letter on this occasion, not so much about the migration, but about the mighty humpback whale itself. Nothing to do with England of course, but in Hawaii the humpback is the centre of attention for tourists and marine biologists alike.
With a graceful splendor this 50’ giant glides effortlessly through the depths. With few natural predators, the humpback whale roams the oceans of the world with almost total impunity. During the fall, it will begin its migration from the rich but icy cold feeding grounds off the Alaskan coast to the warm tropical seas around the equator. Some make the annual pilgrimage to Baja Mexico, while others travel to a small group of islands just south east of Japan. In the main however, almost 70% of north Pacific humpbacks power their great bulk gracefully across 3,500 miles of ocean to the warm waters surrounding Hawaii. There is a definite pattern to the migration with juveniles usually arriving in Hawaiian waters first, followed by adult males, adult females, and finally the pregnant females, who feed for as long as possible to build up reserves enough for them and there unborn calves. The majority of humpbacks settle in the waters off Maui, however, they can be seen from most vantage points around the islands and as I watch them from my home in Hakalau, I can say with confidence, that there is nothing more exhilarating than watching a humpback breach.
The thrill of watching this monster breach is unrivalled.
Relatively speaking… if the humpback had teeth, we would be easy meat. Humpbacks feed only in summer and live off their fat reserves in winter. The long arctic days bring many hours of sunshine and therefore photosynthesis which creates nutrients in the waters for krill and small schooling fish feed upon. The Humpback employs several methods to hunt its prey, but perhaps the most inventive and impressive technique is known as ‘bubble net fishing.’ A group of whales swim in circles and blow bubbles to create a ring of bubbles around schooling fish. The ring encircles the fish, which are confined in an ever-decreasing area as the whales swim in smaller and smaller circles.
The "bubble net" encircles its catch.
Suddenly, the humpbacks, mouths wide open, will swim upward through the bubble net and swallow thousands of fish in one gulp. This species of whale is a ‘baleen,’ which means it has no teeth. Instead, a protein substance called keratin (which incidentally makes up human hair and fingernails), creates approximately 335 baleen plates totaling 2 to 2 1/2 feet in length.These plates hang vertically from the whale’s upper jaw. The whale filters its food by straining water out through its baleen with its tongue. This allows the whale to gulp between 500 and 1000 gallons of water along with 40 to 50 lbs. of food in one mouthful. It can consume approximately one ton of food per day.
Lunging through the bubble net… Yummy! The tropical waters of Hawaii are too warm and nutrient free (which is why our waters are so clear & blue) to support the quantity of the humpback's food sources to sustain them year round. For this reason, after they have given birth and weaned their calves, they must migrate back to the colder northern waters to feed and rebuild their blubber supply. The humpback has few predators; Orcas, some species of sharks, and humans. Individually, although faster, Orcas lack the size and stamina to be successful in an attack against its larger cousin, however, on occasion they will group together into a pack and maintain a sustained attack – which often last for days at a time. A healthy adult humpback will survive such an attack, but juveniles and the infirmed usually succumb to exhaustion. Approximately 20% of all humpbacks have battle scars depicting survival from the angry teeth of battle. On rare occasion, a sick and dying animal might be attacked by some species of sharks, but normally healthy individuals will have nothing to fear from these formidable creatures on a day-to-day basis. By far the biggest predator to worry the humpback is human. A target for the whaling industry throughout the 19th and early 20th centuries, the humpback whale was hunted almost to extinction until in 1966 a whaling moratorium was introduced and the species has since recovered to a worldwide population of 80,000. Humans still remain the biggest danger to these giants of the sea however, as they are still hunted under the guise of ‘scientific research.’ Humans are also responsible for other major causes of humpback deaths… entanglement in fishing gear; collision with ships; noise pollution and underwater electronic warfare are but to mention a few which remain major threats to the survival of the humpback whale to this day. The Humpback Whale is truly a magnificent creature; a gentle giant; a ballet dancer of the deep. The world would be the worse without them and I consider myself privileged to be able to share my home with them.
Posted by Wildlife Sketches at Tuesday, May 05. 2009 
Categories: Amazing Animals,News articles
Tags: wildebeest David Attenborough Hawaii Alaskan Mexico Hakalau Baja Pacific The Great Migration Humpback Whales
Categories: Amazing Animals,News articles
Tags: wildebeest David Attenborough Hawaii Alaskan Mexico Hakalau Baja Pacific The Great Migration Humpback Whales
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