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Conversation 1 - Biology Experiment Reproduction

Listen to part of a conversation between a student and her biology professor.

Professor: So, the assignment is to reproduce one of the animal camouflage experiments we read about in our textbook. Which experiment did you pick?

Student: Well, I was wondering if I can try to reproduce an experiment that’s……kind of the opposite of what was discussed in the textbook?

Professor: So instead of how and why an animal might hide itself, you want to do something about why an animal might want to be seen? Em? Tell me more.

Student: Well, I got the idea from one of the journals you said we should look at.

It’s an experiment about ah……they called them eyes spots in the article?

Professor: Eyes spots, sure. The patterns on the wings of moths and butterflies that are generally believed to scare off predators because they look like big eyes?

Student: Yeah. Except the article was about the experiment that disputes that theory.

Professor: Well, we know that the markings do scare the birds but the idea that the spots looked like eyes is……well, that is just a commonly held belief.

Student: So, that’s not even based on research?

Professor: Well, this whole idea of moths and butterfly markings being scary because they looked like eyes, rest on how we imagine the predators, like birds, perceive the markings. And we can never really know that. All we can do is observe bird behavior. But tell me more about the experiment.

Student: Ok. It said the experiment looked at the shapes of the markings on moths’ wings. The researchers wanted to know if the markings that were round and eyeshaped were more effective in deterring predators than square and rectangular markings.

Professor: OK.

Student: Yeah. So they attached food to paper models of moths with different shaped marks drawn on the wings to see how birds reacted. And what’s interesting is they realized the round marks were not more effective in scaring bird than other shapes.

Professor: Were they less effective?

Student: No, they were about the same. But what researchers did determine is that larger markings were more effective than smaller markings in scaring off prey.

They call this phenomenon “visual aliveness”.

Professor: Visual aliveness. Um. Well, I guess that it is not all that shocking if you think about it.

Student: So anyway, is it ok? Can I repeat this experiment and write about it?

Professor: Yes, I think that’ll work. The problem I proceed is……well……where?

This is an urban campus, you’ll have a hard time finding a good place to set up the experiment.

Student: Oh, I wasn’t planning on doing it on campus. I’m going home for spring break and my family lives in the country, far from the near city. I can set it up in the backyard.

Professor: Good idea. Except one week is not a lot of time, so you will need to make some adjustments to have enough data. I’d set up the experiment near bird feeder and get in as much observation time as you can.