alfred seonyatseng is a senior wildlife warden. >> i think it's going to help all the african countries to know and conserve and to know exactly what the number they have and that they can know how they can conserve their elephants. >> if we don't intervene it's going to be a problem, the elephant will soon disappear. >> reporter: chase is encouraged by the response so far he says that trip to ethiopia gave him a lot of reasons to be hopeful. >> as soon as a government hears that they have 3,000 elephants tucked away in the southern corner of their country, which they didn't know about--man! that changes things, that gets people excited and that's what we've discovered on the great elephant census. >> reporter: and there are many more countries still to be counted. >> sreenivasan: how do you count all the elephants on an entire continent? get an inside look at newshour.pbs.org. >> sreenivasan: there is no shortage of reporting about the health dangers associated with obesity. but scientists at cambridge university in england followed more than 300,000 people over 12 years and concluded