Part A: Design & Execute Study
• Your assignment is to design and execute a study examining the influence of predation risk on other activities.
• Your study can be either experimental or observational, but it must examine the influence of one or more variables on behaviour.
• The following project suggestions include experiments that can be done using an aquarium or a terrarium, in your backyard, a nearby park, a woodlot, a stream, or, if you are lucky enough to live near it, the seashore.
• Each suggestion includes a brief explanation of a trade-off between avoiding predators and performing other activities, such as foraging, courtship, etc. Possible experimental manipulations and study organisms are suggested, and exemplary studies are referenced.
• Feel free to modify any of these project suggestions or to devise your own experiments.
• Your study should be written as if it were a paper to be published in a journal- look at any of the papers you have read in this course for examples.
• Your paper will be evaluated according to the "Project Write-up Guide" that follows the "Project Suggestions" below.
Project Suggestion (Chosen):
• Vigilance (scanning for predators) before and after the appearance of a predator.
Time spent watching for predators (being vigilant) increases an animal's safety but decreases the time it has available for other activities. After a predator appears, animals should become more vigilant. A potential experimental design involves comparing the vigilance of animals at a feeder before and after introducing a predator (a human sitting nearby, or a cat or dog tethered nearby). (Note: Group size must be accounted for because vigilance will vary with group size.)
Gluck, E. (1987). An experimental study of feeding, vigilance and predator avoidance in a single bird. Oecologia, 71, 268-272.
Project Write-up Guide
1. Introduction
The introduction should include a clear discussion of the background of the problem (referencing the relevant literature) and a logical development of the hypothesis (hypotheses), ending in a clear statement of the hypothesis (hypotheses).
2. Objectives
The objectives should include clear and unambiguous predictions.
3. Methods and Materials
Methods and materials should be clearly described. The project should be designed specifically to test the predictions.
4. Results
Presentation of the results should be well organized. Tables and graphs should illustrate results, and appropriate statistical tests and interpretations should be used.
5. Discussion
A good discussion should meet some or all of the following criteria:
• Interprets results with regard to the predictions.
• Relates results to the background literature.
• Suggests problems with the design and potential solutions.
• Raises other research questions.
Part B: Critique of Research Article
Please read the paper below.
Caro, T., Lombardo, L., Goldzien, A., & Kelly, M. (1995). Tail-flagging and other antipredator signals in white-tailed deer: New data and synthesis. Behavioural Ecology, 6(4), 442-450.
Critique Form
1. Introduction
a) What hypothesis (hypotheses) was (were) being tested?
b) If more than one hypothesis was being tested, were they competing hypotheses? Explain.
c) Into which of the three levels of explanation (of behaviour) introduced in Unit 1 did each hypothesis fit? Justify your answer.
d) If the hypothesis concerned the ultimate ("why") causes of the behaviour, was the logic based on individual or group selection? Explain.
e) Did the introduction develop the hypotheses logically? Justify your answer.
2. Predictions
a) For each hypothesis, state the predictions that were tested (using graphs wherever appropriate).
3. Methods
a) Was the method used to test the predictions experimental? Explain.
b) If the method was experimental, for each prediction tested, what experimental treatments were used, why, and what results were predicted?
c) If the method was non-experimental, were predictions tested using direct observation or comparative data from other species? Explain.
d) i) If direct observation was used, for each prediction tested, what aspects of behaviour were observed, why, and what results were predicted?
ii) If comparative data were used, for each prediction tested, how did the animals whose behaviours were compared differ? Also, why did the investigator feel that these differences would provide a test of that prediction?
4. Results and Discussion
a) What did the investigator(s) conclude?
b) Why did the investigator(s) conclude this from the data?
c) Are you convinced that the conclusion(s) is (are) correct? Justify your answer.
d) What would improve the strength of the conclusion(s)? Explain.
Part C: Long Answer Questions (60 Marks) - approx. 250 word response each
1. When Scott Creel and his colleagues studied elk behaviour in Montana, they found that elk tended to form larger groups when foraging in the open far away from forest cover. Why might this result lead us to interpret large group formation by elk as an antipredator response? Creel and company noted that the elk aggregated only on days when wolves were absent. In the presence of wolves, elk remained in small herds. What is the significance of these observations for the antipredator hypothesis for the tendency of elk to group together under some conditions? In scientific terms, what label should be given to these observations: hypothesis, prediction, test data, or scientific conclusion? What is the significance of this work for studies of mud-puddling by butterflies? (20 marks)
2. Inhibitory neural messages often play a key role in organizing the behaviour of an animal, as the mantis demonstrates. Mature female crickets (Gryllusbimaculatus) approach chirping males. About one hour after mating, during which the male transfers a spermatophore to his partner, the female stops tracking the calls of males of her species. If you found that emptying the sperm storage organ caused the female to resume responding to calling males, you could speculate on how the female cricket's nervous system controlled this aspect of her behaviour. How might inhibitory messages be involved? What is the adaptive significance of this proximate mechanism?
3. Although the number of cases of mate choice by females dwarfs the known examples of choosy males, that rarer form of mate choice does occur and may be more widespread than often appreciated. In this light, why might it be adaptive for male jungle fowl to enhance the speed with which their sperm can travel when roosters inseminate attractive versus unattractive females? Why might male potbellied seahorses strongly prefer to court large females, whereas females show no such preference for large males? And why might male black widow spiders bias courtship in favour of well-fed females as opposed to starved ones?