Peacock butterfly: Eye spots

Question 1

Prey survival by predator intimidation: an experimental study of peacock butterfly defence against blue tits.

Auther and date?

Answer 1

Vallin et al (2004)

Question 2

How does the Peacock butterfly intimidate potential predators?

Answer 2

Flashing eye spots and hissing noises

Question 3

What were the experimental predators of the peacocks?

Answer 3

Wild-caught Blue tits

Question 4

What was the experiment?

Answer 4

Manipulated different areas of the butterflies defence (e.g. eye spots or hissing).
Experimentally exposed them to wild-caught blue tits to see outcome of defences.

Question 5

How were the butterflies modified for the experiement?

Answer 5

• Eye spots were covered.
• Wings were cut to change their shape.
• Hissing noise from wings was blocked.

Question 6

How long did a trial last?

Answer 6

• 30 minutes
• would be terminated early if a butterfly was consumed.

Question 7

What was considered an interaction?

Answer 7

1. Would start when a butterfly reacted in a visible way to a bird on the log.
2. Would end with butterfly being eaten or bird flying away from the log.

Question 8

What was measured?

Answer 8

• Survival of the butterfly
• Distance to bird when butterfly initiated wing-flickering
• Number of interactions
• Time between interactions

Question 9

How did the butterflies react to the birds?

Answer 9

They would show their wings and tilt their bodies and rotate on the log in the direction of the bird.

Question 10

What did the butterfly do if the bird returned for another attack?

Answer 10

Flick their wings and increase the rate of the flicking as the bird approached.

Question 11

Results

Answer 11

• All butterflies were found and attacked by birds
• Forty butterflies survived
• 14 were consumed
• 1 of 34 butterflies with intact eyespots died.
• 13 out of 20 butterflies with covered eyespots were killed.
• Hissing had no effect.

Question 12

How would hissing be effective with other predators?

Answer 12

Hissing may be effective for intimidating bats

Question 13

When did wing flicks increase?

Answer 13

Butterflies with covered eyespots showed higher rates of wing-flicks.

Possibly due to birds spending more time closer to butterflies with covered eyespots so the butterflies flicked their wings more.

Question 14

Eyespots are imitation strategy, why?

Answer 14

All killed butterflies were eaten which suggests they were not distastful.
The eyespots are a form of bluffing and are an efficient way of defending against predators.