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.
❓ 講義によると、カッコウの個体数がシジュウカラの個体数よりも急速に減少しているのはなぜか。
A. A. カッコウは日照の変化の手がかりに影響を受ける。
B. B. カッコウは、昆虫の発生ピークに合わせて繁殖時期を調整することができない。
C. C. カッコウは春の寒さにより、雛の数が少なくなっている。
D. D. カッコウは渡りを始めるために温度の手がかりに依存している。
✅ 正确答案
B. Cuckoos cannot adjust their breeding timing to match insect peaks.