Eyeliner On Spiders: It's For Science

Aug 18, 2018
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JENNIFER LUDDEN, HOST:

We learned this week that scientists in Florida are putting eyeliner on spiders. Why? Well, to understand, you need to know male jumping spiders are pretty flamboyant during mating rituals. They vibrate and dance. And they're pretty colorful too.

LISA TAYLOR: A lot of males have bright red faces, and a lot of males have like these bold black-and-white stripes.

LUDDEN: Lisa Taylor is a biologist at the University of Florida who studies the arachnids. And her lab is in the middle of an experiment to find out what those colors mean.

TAYLOR: A lot of these color patterns are similar to the color patterns that prey use to identify that they are toxic. So like, things like ladybugs are toxic, and they advertise that with a red body and black dots. And so what we think is going on is that the males are putting these color patterns on their faces to kind of, like, make them look like unappealing prey.

LUDDEN: And they want to look unappealing because the females are hungry. We asked Dr. Taylor to explain.

TAYLOR: So most jumping spiders of females are a lot bigger than the males. And they're tiny, but they're voracious predators. And so the male has this challenge where he has to attract the attention of the female and convince - you know, send the female a little bit of information that he wants to mate, and he's the right species but then, also at the same time, convince the female that he's not an appealing meal.

LUDDEN: The females are cannibals.

TAYLOR: They are, yes.

(LAUGHTER)

LUDDEN: OK. So you have been experimenting with the color. First, what question are you trying to answer?

TAYLOR: So we're trying to understand how males can achieve this delicate balance of attracting a female's attention and sending her the information that she needs while also avoiding getting eaten.

LUDDEN: What are you actually painting on them?

TAYLOR: We needed something that could go on really delicately that was also nontoxic. So the best thing we found is makeup. One of the species that we're working with - the males have these bright red faces. And so we want to know whether the females are paying attention to that bright red face. One thing we can do is take this fancy liquid eyeliner and cover up the male's face - so he no longer has a red face, now he has a completely black face - and then ask the female, OK, does this change how you would interpret that male's display. Would this make you less likely to eat him? Would it make you less likely to mate with him?

LUDDEN: Have you noticed any different reactions in the females?

TAYLOR: Yeah, so with the stripes, we know if we give them prey that have different colors and patterns, we know that females are more attentive to the striped prey. But they're not more likely to attack it. So that kind of supports the idea that maybe those stripes are a strategy that's used by males to get the females' attention without eliciting extra attacks.

LUDDEN: So you go shopping for your supplies where?

TAYLOR: Sephora often (laughter). We get a lot of strange looks because we often go, and we're looking really closely at these things. And we're, you know, having conversations - like, how do you think this one will look? Or, you know, do you think this one will go on really cleanly on the face? And so usually the makeup artists will come and say, can we help you? Sometimes we tell them what we're doing. Sometimes if a store is really crowded, we just kind of keep to ourselves (laughter).

LUDDEN: Dr. Lisa Taylor researches behavioral ecology and evolution at the University of Florida. Thanks, very much.

TAYLOR: Yeah, thanks for having me.

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