Smelling Out the Enemy. Snakes deposit chemical trails as they travel through their habitats. These trails are often detected and recognized by lizards, which are potential prey. The ability to recognize their predators via tongue flicks can often mean life or death for lizards.

Scientists from the University of Antwerp were interested in quantifying the responses of juveniles of the common lizard (Lacerta vivipara) to natural predator cues to determine whether the behavior is learned or congenital. Seventeen juvenile common lizards were exposed to the chemical cues of the viper snake. Their responses, in number of tongue flicks per 20 minutes, are presented in the following table. [SOURCE:

Van Damme et al., “Responses of Na¨ıve Lizards to Predator Chemical Cues,” Journal of Herpetology, Vol. 29(1), pp. 38–43]

425 510 629 236 654 200 276 501 811 332 424 674 676 694 710 662 633 Find and interpret a 90% confidence interval for the mean number of tongue flicks per 20 minutes for all juvenile common lizards. Assume a population standard deviation of 190.0.