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Listen to an Academic Talk Test #006
Listen to an Academic Talk
1. What is the lecture mainly about?
A) The nesting habits of warblers
B) A reproductive strategy used by some birds
C) How birds learn to identify their own chicks
D) The physical similarities between different bird species
2. According to the professor, what does a newly hatched cuckoo chick do?
A) It learns to mimic the host bird's song.
B) It helps the host parents care for other chicks.
C) It removes the host's eggs or chicks from the nest.
D) It changes the color of its feathers to match the host.
3. What does the professor imply about host birds?
A) They often abandon their nests if a parasite is found.
B) They are not very attentive parents to their own young.
C) They are under evolutionary pressure to detect foreign eggs.
D) They have larger nests than parasitic birds.
4. Why does the professor mention a "co-evolutionary arms race"?
A) To describe competition for food between different species.
B) To explain why cuckoos are becoming less successful.
C) To illustrate the conflict between male and female cuckoos.
D) To characterize the ongoing adaptations of hosts and parasites.
Professor: Today we'll discuss a fascinating, if a bit ruthless, survival strategy in the animal kingdom: brood parasitism.
This is when one animal, the parasite, tricks another, the host, into raising its young.
The classic example is the Common Cuckoo. A female cuckoo will find the nest of a smaller bird, like a warbler, and lay her own egg in it, often removing one of the host's eggs.
The cuckoo's egg is often a very close match in color and pattern to the host's eggs, making it difficult to detect.
Once the cuckoo chick hatches—which it usually does first—it instinctively pushes the other eggs or chicks out of the nest.
This ensures it gets all the food from the unsuspecting host parents.
It's an incredibly effective strategy for the cuckoo, but it has led to what biologists call a co-evolutionary arms race, with hosts evolving better defenses and parasites evolving better trickery.
This is when one animal, the parasite, tricks another, the host, into raising its young.
The classic example is the Common Cuckoo. A female cuckoo will find the nest of a smaller bird, like a warbler, and lay her own egg in it, often removing one of the host's eggs.
The cuckoo's egg is often a very close match in color and pattern to the host's eggs, making it difficult to detect.
Once the cuckoo chick hatches—which it usually does first—it instinctively pushes the other eggs or chicks out of the nest.
This ensures it gets all the food from the unsuspecting host parents.
It's an incredibly effective strategy for the cuckoo, but it has led to what biologists call a co-evolutionary arms race, with hosts evolving better defenses and parasites evolving better trickery.
Highlights
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