Once you've found the birds, the next job is harder: to investigate each stage in their natural history, from how they find food and grow to how they breed and die.
鳥兒有了，接下來的工作將更困難：鳥兒生活史得一一調查，從覓食、成長，到繁殖、死亡，每一步驟，都可以是一篇論文。