Today in our biology lecture, we'll discuss the impact of climate change on migratory birds. Recent studies show that warmer springs cause insects to emerge earlier, but many bird species still arrive at their breeding grounds at the same time. This mismatch means that by the time chicks hatch, the peak insect availability has passed, leading to lower chick survival rates. Interestingly, some species, like the great tit, have adapted by laying eggs earlier. However, long-distance migrants, such as the cuckoo, cannot adjust their arrival dates because they rely on daylight cues, not temperature. As a result, their populations are declining more rapidly.
❓ 根据讲座内容，为什么杜鹃种群的下降速度比大山雀种群更快？
A. A. 布谷鸟受到日照变化线索的影响。
B. B. 杜鹃无法调整其繁殖时间以与昆虫高峰期相匹配。
C. C. 由于春季变冷，布谷鸟的雏鸟数量减少。
D. D. 杜鹃鸟依靠温度线索来开始迁徙。
✅ 正确答案
B. Cuckoos cannot adjust their breeding timing to match insect peaks.