Blog # 236 The Amazing Egg
The avian egg has all the embryo needs to survive and grow. Bird eggs are amazing: self-contained wonders, like tiny spaceships with life support systems. Eggs sustain life while inside, rapidly dividing cells miraculously construct a living embryonic bird, getting ready to break out into the world. It takes about 36 hours to form a fertilized osprey egg, but there is more to the story than that. Our osprey eggs’ tale began months ago in late winter when Ophelia’s shifting estrogen levels triggered her urge to migrate home. In non-migrant bird species, changing day length often stimulates this hormone surge, but not in the case of migrant ospreys. The cause of osprey “Zugenruhe” or the uncontrollable urge to migrate remains a true scientific mystery. During her 2,000-4,000-mile, month-long flight north to her nest, three eggs began to develop in her ovary and yolk was deposited in them. The lipid-rich yolk, filled with energy and tinted yellow-orange by anti-oxidants, will