As forests shrink and conflicts rise, conservationists race to protect the last 50,000 of the species Populations have declined by more than 50% in the past three generations, and the largest land mammals in Asia now occupy just 15% of their historical range Experts stress the need for coordinated measures to protect a ‘keystone species’ whose presence shapes ecosystems and supports countless others ISTANBUL  Once dominant in the vast forests they roamed freely, Asian elephants now walk a