Twenty-five miles south of Baltimore~2,in a grassy pen~3enclosed by two rows of fences,electrified~4to provide protection against raccoons and monitored by video cameras,a pair of the tallest birds in North America emerge from their hut.Powder-white,all neck and legs5,they step through the rain with care,as if in high Twenty-five miles south of Baltimore ~ ​​2, in a grassy pen ~ 3enclosed by two rows of fences, electrified ~ 4to provide protection against raccoons and monitored by video cameras, a pair of the tallest birds in North America emerge from their hut. Powder -white, all neck and legs5, they step through the rain with care, as if in high