Dr Jhala and colleagues assessed their method by collecting paw prints and faeces at 21 forest sites in central and northern India.
Jhala博士和同事们通过在印度中部和北部的21座森林里收集脚印和粪便来评估他们的方法。
Dr Yadvendradev Jhala of the Wildlife Institute of India, who led the study, said: "Tigers are cryptic, nocturnal and occur at low densities so they are extremely difficult to monitor.
