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.
❓ Согласно лекции, почему популяции кукушек сокращаются быстрее, чем популяции больших синиц?
A. A. Кукушки подвержены влиянию изменений световых сигналов дня.
B. B. Кукушки не могут корректировать сроки своего размножения, чтобы совпадать с пиками численности насекомых.
C. C. У кукушек меньше птенцов из-за более холодных вёсен.
D. D. Кукушки полагаются на температурные сигналы для начала миграции.
✅ 正确答案
B. Cuckoos cannot adjust their breeding timing to match insect peaks.