The Houston Zoo successfully hatched two new Blue-billed Curassow chicks yesterday. Considered some of the most critically endangered birds, the Houston Zoo will be hand-rearing one chick (cared for by a person after hatching) and using the blue-billed curassow hen to parent-rear the other chick. Due to its rarity, it’s been over 25 years since the Houston Zoo has attempted parent-rearing after hatching a curassow chick.