Rising Tide Images
Beach Find
Back from its annual breeding migration, this ruddy turnstone finds something of interest. Its nesting range on the tundra of Alaska, Canada, and Siberia requires a return trip to tropical Hawaii of approximately 3,000 miles of open ocean in an exhaustive, marathon effort of 3 to 4 days and nights of nonstop flight. Turnstones use the stars and the earth’s magnetic field to find their way over the featureless ocean to the same small patch of territory every year. They may use the earth’s magnetic field visually with the magnetoreception molecules of cryptochrome in their retina. The Hawaiian name, ‘akekeke, resembles the sound of their call. The physiological changes in migratory shorebirds, like this ‘akekeke, are astonishing. The necessity of increasing fat load for the sustained energy demands of long-distance migration has been compared to, in terms of percentage body fat, larding up to morbid obesity in humans. The surge in heart and lung capacity and increase in pectoral flight muscle are driven by hormonal changes (without the drudgery of exercise!).
Beach Find
Back from its annual breeding migration, this ruddy turnstone finds something of interest. Its nesting range on the tundra of Alaska, Canada, and Siberia requires a return trip to tropical Hawaii of approximately 3,000 miles of open ocean in an exhaustive, marathon effort of 3 to 4 days and nights of nonstop flight. Turnstones use the stars and the earth’s magnetic field to find their way over the featureless ocean to the same small patch of territory every year. They may use the earth’s magnetic field visually with the magnetoreception molecules of cryptochrome in their retina. The Hawaiian name, ‘akekeke, resembles the sound of their call. The physiological changes in migratory shorebirds, like this ‘akekeke, are astonishing. The necessity of increasing fat load for the sustained energy demands of long-distance migration has been compared to, in terms of percentage body fat, larding up to morbid obesity in humans. The surge in heart and lung capacity and increase in pectoral flight muscle are driven by hormonal changes (without the drudgery of exercise!).