Question

Question: How does prey density affect search time and handling time? Hypothesis: Greater prey density  lower search time, handling time You will need 2 timekeepers – one for search time (t.t.d. = time to discovery) One for handling time (h.t.) 1 data scribe 1 predator Experimental design: make a field of background objects, place your prey items randomly in this field. For example: Your setup could be a field of less desirable wrapped candies, and the prey can be more desirable Hershey’s kisses; or perhaps a background of peanuts in the shell, and the prey some other more delectable object (in these cases the predator can really eat the prey); or you might use all non-edible objects for background and prey, but something to manipulate on the prey items like folding them up, unwrapping, something to represent “handling time”. The blindfolded predator must search until one prey is encountered and picked up (t.t.d. recorded); then the predator unwraps and eats the prey (h.t. recorded when finally swallowed and finger signals ‘done’) The predator keeps searching and eating until all prey are discovered. REPEAT for each density with same predator. Repeat overall experiment at least once, changing roles, with a different person as predator. With your data: For each predator, calculate the mean search time and handling time for each density. Plot your results on a graph with prey density on the x-axis and the response variable(s) on the y-axis. What can you conclude? Interpret your results. Compare among predators and discuss possible reasons for any differences. Each student will write a short report describing their set-up, their data summary, and interpretation, and submit it for one essay credit.

Answer 1