What’s that Smell?

1. What’s that Smell? Alyson McCroskey, Lauren Williams, Maggy Gleason

2. What’s That Smell?Habitat Preference for decorated crickets, Gryllodes sigillatus,based on predator olfactory cues from feces of the Leopard Gecko, Eublepharismacularius.

3. Introduction: • Predator avoidance may occur if prey can detect predators early, which therefore may increase fitness. (Brettschneider & Bateman 2004). • Visual, acoustic, and olfactory cues • Predators may leave behind olfactory cues in the form of feces. Feces supplies the prey with information about the threat status of a predator(Madison et al., 1999).

4. Introductions: • Gryllodes sigillatus – known as the decorated cricket. • Located in South Western United States • Common predators include; spiders, birds, mice, and lizards. (Kortet, R. & Hendrick A. 2004)

5. Introduction: • Eublepharis macularius- known as Leopard Gecko • Geckos orient themselves to the male cricket call, so they can consume the females that come looking for a mate. (Sakaluk & Belwood, 1984).

6. Introduction: • Crickets may use olfactory cues to identify predators in their habitats. • Females use chemosensory cues to detect males they have previously mated with to avoid mating with that male again.(Ivy et al., 2005).

7. Introduction: Hypothesis • If crickets use olfactory cues to detect a predator, then they would prefer habitats without the predator. • Prediction: When crickets are given a choice between two habitats, one with the presence of predator olfactory cues and one without, they will choose the habitat without the cue.

8. Methods: • November 16, 2008 at Illinois State University • Sampled 30 male and 30 female decorated crickets that were previously isolated into male and female containers for 1 week. • Trials were conducted during the dark phase of the photoperiod under red light illumination. • Feces was collected from 2 leopard geckos at University High School which are fed mainly meal worms, and sometimes crickets.

9. Methods: • 12 shoebox sized plastic containers • Solution of Leopard gecko feces- 90ml of tap water and approximately 2 grams of crushed feces. • Cotton balls • One zero sampling in 30 second intervals for a total of 15 minutes

10. Display of Containers and Cotton Ball Positioning

11. Lab Set UP

12. Under Red Light

13. Methods: Calculations • Statistical analysis using a one – tailed t-test, with a significance level of α = 0.05 • Calculations were done using proportions • Intervals spent on the side ÷ total number of intervals

14. Results: Male: t58= 1.51, P > 0.05Not Significant

15. Results:Female: t58= 4.79, P < 0.05 Significant

16. Discussion • Our hypothesis was not supported, male and female decorated crickets did not spend a larger proportion of time on the side without the feces olfactory cue. • Both spent a larger proportion of time on the side with the feces olfactory cue. • Only significant in females

17. Discussion • Predator avoidance is less common in invertebrates (Brettschneider & Bateman 2004). • In another experiment, Platygryllus primiformis, preferred shrew feces-treated habitat to a water treated habitat(Brettschneider & Bateman 2004)

18. Discussion: • Females use olfactory cues for mating(Ivy et al., 2005). • Crickets raised in captivity, never exposed to predators • Novel smell, curiosity

19. Discussion • Error: Geckos did not consume crickets before feces samples were collected • Predator feces give off olfactory cues based on the prey they consume. The prey can chemically label these cues as a high risk predator. (Madison et al., 1999). • Larger sample size and increase total time of experiment.

20. Discussion: • Future experiments • Possible differences in the development of male and female sensory organs. • Test different sensory cues visual and auditory.

21. References: • Brettschneider, H. & Bateman, P. 2004. Differential shelter selection in response to predator chemical cues by two orthopterans: Libanasidusvittatus(Anostostomatidae) and Platygryllusprimiformis(Gryllidae). Journal of Insect Behavior, 18: 381-387.  • Ivy, T. M., Weddle, C.B., Sakaluk, S.K. 2005. Females use self-referent cues to avoid mating with previous mates. Proceedings of the Royal Society of London Series B, 272: 2475–2478. • Kortet, R. & Hendrick, A. 2004. Detection of the spider predator, Hololenanedra by naïve juvenile field crickets (Gryllus integer) using indirect cues. Behaviour 141: 1189- 1196. • Madison, D.M., Maerz, J. C., and Mcdarby, J. H. 1999. Optimisation of predator avoidance by salamanders using chemical cues: Diet and dieleffects. Ethology105: 1073-1086 • Sakaluk, S.K. & Belwood, J.J. 1984. Gecko Phonotaxis to cricket calling song: A case of Satellite Predation. Animal Behanivor, 32: 659-662.