it's amazing to think that we now have over 150,000 elephant seals just here in california. at piedras blancas we had around 4,500 seals born last year. all these pups out here on the beach but no mothers, where's mommy at? she's back out at sea. the amazing part about these animals is that they fast when they're here. and the pups, right now they're even fasting. these seals are born and then fed the richest milk in the entire animal kingdom, super rich in fat. and in only four weeks time, they quadruple their body weight. the females lose about a third of their body weight between giving birth and fasting when they're here. but then they take off and they leave the pups here where for 8 to 10 weeks they're going to learn how to be seals, how to swim on their own. during this time they call them weeners and that's what we have a beach full of here - a beach full of seal weaners. the big males fast too and that's even more extreme. a giant male like we see here may have lost 1500 pounds over the breeding season because they're here for three months. and these animals don't j

. >>> tonight on "quest" -- elephant seals dive deeper, swim farther and hold their breath longer than almost any mammal on earth. but how do they accomplish such remarkable feats? bay area scientists have begun to unlock the secrets of these aquatic athletes. >>> and after multiple unmanned missions to mars, we still don't know if life has ever existed there. nasa scientists are hoping a new high-tech rover will help them solve the mystery. >>> major funding for "quest" is provided by the national science

. >>> tonight on "quest" -- elephant seals dive deeper, swim farther and hold their breath longer than almost any mammal on earth. but how do they accomplish such remarkable feats? bay area scientists have begun to unlock the secrets of these aquatic athletes. >>> and after multiple unmanned missions to mars, we still don't know if life has ever existed there. nasa scientists are hoping a new high-tech rover will help them solve the mystery. >>> major funding for "quest" is provided by the national science foundation and the corporation for public broadcasting. additional support is provided by -- the richard and rhoda goldman fund.

. >>> tonight on "quest" -- elephant seals dive deeper, swim farther and hold their breath longer than almost any mammal on earth. but how do they accomplish such remarkable feats? bay area scientists have begun to unlock the secrets of these aquatic athletes. >>> and after multiple unmanned missions to mars, we still don't know if life has ever existed there. nasa scientists are hoping a new high-tech rover will help them solve the mystery. >>> major funding for "quest" is provided by the national science

seals like kasey are musical by nature. they sing to their mates an the zoo says kasey even seemed to sing along with the saxophone. by the way the elephantsgot a saxophone concert but they couldn't have cared less. >>> coming up next here the epidemic of tiny toddlers with dad's smart phone. the random tapping that purchases some really pricey items. let's play: [ all ] who's new in the fridge! i help support bones... [ ding! ] ...the immune system... [ ding! ] ...heart health... [ ding! ] ...and muscles. [ ding! ] that can only be ensure complete! [ female announcer ] the four-in-one nutrition of ensure complete. a simple choice to help you eat right. [ major nutrition ] nutrition in charge. i took my son fishing every year. we had a great spot, not easy to find, but worth it. but with copd making it hard to breathe, i thought those days might be over. so my doctor prescribed symbicort. it helps significantly improve my lung function starting within five minutes. symbicort doesn't replace a rescue inhaler for sudden symptoms. with symbicort, today i'm breathing better. and that means...fish on! symbicort is for copd including chronic bro