Return to Lab Notes A literature review of wolf-moose interactions in North America was conducted. Studies from different locations across North American were included, however only studies in which moose were the dominant prey species of wolves were included. Three parameters were obtained from each study. These parameters were moose density (number/km2), wolf density (number/1000 km2), and kill rate (number of moose killed/wolf/100 days). All three parameters were measured during winter when moose and wolves were observed from aircraft. Data from different areas were partitioned into low vs. high wolf kill rates. We collected these data because we were interested in looking at the functional and numerical responses of wolves to changes in moose density in relation to low and high kill rates.
Download the file wolfmoosedata.xls from K:/WLF/448/2004/Lab2004/Predation/ onto to your zip or H: drive. In this file you will find 2 worksheets (low vs. high kill rate) and data on the three parameters explained above. These data are generally based on Messier (1994) and Hayes and Harestad (2000). Use these data to explore the functional and numerical responses of wolves to moose density by addressing the following questions.
Define functional response in relation to our predator prey interaction using wolves and moose. (1 point)
Define numerical response in relation to our predator prey interaction using wolves and moose. (1 point)
Using the low wolf kill rate data graph the functional and numerical responses of wolves to moose density. Create 2 separate graphs and be sure to correctly title and label the axes. You can use MS Excel to create the graphs. Be sure to choose the 'XY Scatter' plot to look at the data. Once you have created the 2 graphs, draw a line through the points that you think best fits the data. You can draw this by hand. For the functional response, is the line you drew through the data points, a Type 1, 2, or 3 curve? For the numerical response, is the line you drew through the data points, a Type 1, 2, 3, 4 or 5 curve? For each the functional and numerical response, is the predator-prey interaction stable? (5 points)
Explain why you think wolves show these types of functional and numerical responses at low wolf kill rates. Be sure to discuss predator and prey density dependence, handling time, prey switching, etc. (2 points)
Using the high wolf kill rate data graph the functional and numerical responses of wolves to moose density. Create 2 separate graphs and be sure to correctly title and label the axes. You can use MS Excel to create the graphs. Be sure to choose the 'XY Scatter' plot to look at the data. Once you have created the 2 graphs, draw a line through the points that you think best fits the data. You can draw this by hand. For the functional response, is the line you drew through the data points, a Type 1, 2, or 3 curve? For the numerical response, is the line you drew through the data points, a Type 1, 2, 3, 4 or 5 curve? For each the functional and numerical response, is the predator-prey interaction stable? (5 points)
Explain why you think wolves show these types of functional and numerical responses at high wolf kill rates. Be sure to discuss predator and prey density dependence, handling time, prey switching, etc. (2 points)
Why do you think there are different functional and numerical responses of wolves to moose density at low and high wolf kill rates? (4 points)
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Revised: 13 November 2004