eagles once on the brink of extinction are again taking flight. but with success there's often struggles. cbs's lilia luciano has more. >> like many expectant couples jackie and shadow anxiously await a new addition to their family. from a 150 feet up on this pine tree overlooking california's big bear lake. america's bald eagle population has more than quadrupled in the last decade. but here in the golden state the species is still in endangered. the stakes are high for jackie and shadow who have been protecting their egg for 45 days. >> can you give us a status update. what is the latest. >> at this point it's very unlikely that it would hatch. >> sandy helps run the conservation group friends of big bear valley where she has been watching the feathered pair for years. >> what is the challenge in getting them to hatch. how difficult is it. >> they have to guard them all the time from predators. they have to keep them warm and