[00:00.00]NARRATOR: Listen to part of a conversation between a student and her biology professor.[00:06.53]MALE PROFESSOR: So the assignment is to reproduce one of the animal camouflage experiments we read about in our text book. [00:13.10]Which experiment did you pick?
[00:15.10]FEMALE STUDENT: Well... I was wondering if I could try to reproduce an experiment that's kinda the opposite of what was discussed in the textbook?[00:23.02]MALE 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? [00:31.51]Hmmm. Tell me more.
[00:33.66]FEMALE STUDENT: Well, I got the idea from one of the journals you said we should look at…[00:37.21]it's an experiment about, um, they called them eyespots in the article?
[00:42.95]MALE PROFESSOR: Eyespots, sure, [00:44.51] the patterns on the wings of moths and butterflies that are generally believed to scare off predators because they look like big eyes.
[00:51.77]FEMALE STUDENT: Yeah, except the article was about an experiment that disputes that theory.[00:56.14]MALE PROFESSOR: Well, we know that the markings do scare the birds, but the idea that the spots look like eyes is, well that's just a commonly held belief.[01:06.12]FEMALE STUDENT: So—that's not even based on research?
[01:09.33]MALE PROFESSOR: Well, this whole idea of moth or butterfly markings being scary because they look like eyes rests on how we imagine that their predators—like birds—perceive the markings. [01:20.62]And we can never really know that. [01:22.79]All we can do is observe bird behavior. [01:25.79]But tell me more about the experiment.[01:28.34]FEMALE STUDENT: OK, so the experiment looked at the shapes of the markings on moth wings. [01:33.10]The researchers wanted to know if the markings that were round or eye-shaped were more effective at deterring predators than square or rectangular markings.[01:41.33]MALE PROFESSOR: OK…
[01:42.44]FEMALE STUDENT: Yeah. So, they attached food to paper models of moths, with different shaped marks drawn on the wings, to see how birds reacted. [01:49.94]And what's interesting is, they realized that the round marks were not more effective at scaring birds than other shapes.[01:56.55]MALE PROFESSOR: Were they less effective?
[01:58.44]FEMALE STUDENT: No, they were about the same... [02:00.77]but what researchers did determine is that larger markings are more effective than smaller markings at scaring off prey. [02:07.23]They called this phenomenon “visual loudness.”
[02:10.49]MALE PROFESSOR: Visual loudness, huh. [02:12.62]Well, I guess it's not all that shocking, if you think about it.[02:16.80]FEMALE STUDENT: So, anyway, is it OK? [02:19.44]Can I repeat this experiment and write about it?[02:22.25]MALE PROFESSOR: Yes, I think that'll work. [02:24.46]The problem I foresee is, well, where? [02:28.16]This is an urban campus...You'll have a hard time finding a good place to set up the experiment.
[02:33.29]FEMALE STUDENT: Oh, I-I wasn't planning on doing it on campus. [02:36.17] I'm going home for spring break, and my family lives in the country, far from the nearest city. [02:40.77]I can set it up in the backyard.
[02:42.60]MALE PROFESSOR: Good idea. [02:43.66]Except one week is not a lot of time. So you'll need to make some adjustments to have enough data. [02:49.99]I'd set up the experiment near a bird feeder, and get in as much observation time as you can.
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