INTELLIGENCE, POWER, 



The beautiful egrets are largely insectivorous. They 

 follow the herds of buffalo and elephant through the dense 

 swamps of reeds and feathery papyrus, often lighting on 

 the backs of these large animals. Their habit of darting 

 after swift-flying insects, taking them on the wing, as the 

 elephants and buffalo force their way through the thick 

 reeds, or searching out worms and larvae as the feet of 

 these animals uncover them in the marshy ground suggest 

 that the egret bird possesses a preponderance of adrenal 

 glands over thyroid gland, as compared with the ratio 

 found in the passively soaring vulture or in birds such 

 as the stately crested crane that quietly pick up their 

 food while they walk on the veldt. 



The adrenal glands in the African yellow-billed egret 

 showed a preponderance over the thyroid gland of 14 to 7, 

 and in the great white egret, of 21 to 13; in the crested 

 crane the preponderance was 30 to 26 and in the guinea 

 fowl, 36 to 29. The greatest preponderance of adrenal 

 glands over thyroid gland, hence of flash energy over con- 

 stant energy, that we found among the birds in Africa, was 

 in the eagle, which is a bird of prey. 



Another interesting contrast in the energy characteristics 

 of birds is seen between the European stork and the 

 adjutant or marabou stork. Each year the European stork 

 makes its migration from Northern Europe to the Rift 

 Valley, where locusts drop at its feet. Such a long migration 

 would necessitate sustained energy. The European stork 

 exhibits an adrenal-thyroid energy pattern of 49 to 43. 



The marabou stork of Africa is not a migrating bird. 

 Like the vultures, it is a scavenger. Its flight is powerful 

 and reaches incredible heights. But the marabou stork is 

 pugnacious. It dominates the vultures at the kill. The 

 adrenal glands of the marabou stork are more than three 

 times larger than the thyroid gland. 



The pink flamingo, one of the goose tribe, lazily feeds on 

 aquatic invertebrates and seems to make no special energy 



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