One of the world’s most endangered species — a North Island brown kiwi — has just hatched at the Smithsonian’s National Zoo Bird House. Keepers had been incubating the egg for five weeks, following a month long incubation by the chick’s father, carefully monitoring it for signs of pipping: the process in which the chick starts to break through the shell. The chick remained in an isolet for four days and is now in a specially designed brooding box.