Evaluate how the authors set up an experiment to test their idea that male metabolic rate might respond differently to the threat of a predator than female metabolic rate does

Journal Article: Lagos, P.A. and M.E. Herberstein. 2017. Are males more scared of predators? Differential change in metabolic rate between males and females under predation risk. Physiology andBehavior. 173:110-115.

The purpose of this discussion is to evaluate how the authors set up an experiment to test their idea that male metabolic rate might respond differently to the threat of a predator than female metabolic rate does. Pay careful attention to which variables the authors keep the same for all the animals and which variable(s) they manipulate to test their idea. Look at the authors’ results and decide what you think the answer is to their question.

Discussion Questions

Introduction

1. What is the authors’ research question?

2. What hypothesis are the authors testing?

3. What specific predictions do the authors make from their hypothesis?

4. Knowing the authors’ hypothesis, state the null hypothesis. (It is not stated in the article, only

implied.)

5. What specific predictions can you make from the null hypothesis?

Materials and Methods

6. What were the living conditions of the crickets before the experiment?

7. What dependent variable do the authors measure?

8. What independent variable do the authors manipulate?

9. What other variables do the authors take into consideration that might influence the

independent variable?

10. A treatment is the range of conditions for the independent variable. What are the treatments in

this experiment?

11. Describe the control.

12. How was the procedure different between the control treatment and the predator treatment?

13. What do the authors do to find out if the procedural difference matters?

14. How many animals were tested in total? Were equal numbers of males and females tested? Do

you think it matters?

Results: Figure 2.

15. What do the bars show? What do the error bars represent?

16. Data in Figure 2 were collected from how many animals?

17. Does CO2 production change in response to the smell of a predator?

Results: Figure 3.

18. Fig. 3A. What was the test procedure for Control 1?

19. Fig. 3A. What is the logic behind the test procedure used for Control 2? 20. Fig. 3B. What is the logic behind testing the response to eucalyptus scent?

Results: Figure 4.

21. What is missing from Figure 4 that you should always include in graphs?

22. Is CO2 production different between males and females in the control treatment? 23. What effect does the smell of a predator have on CO2 production?

24. Is the effect different between males and females?

Inference

25. Are males more scared of predators than females? Give evidence from the results to support

your answer.