Question

canine distemper is a highly contagious disease that can be lethal for wolves, especially for pups and older adults. canine distemper outbreaks occurred in yellowstone national park in 1999, 2005, 2008, and 2017. based on the graph, indicate how each distemper outbreak impacted wolf population growth.

outbreak year	during the outbreak year, the wolf population size...
1999	◯	◯	◯	◯
2005	◯	◯	◯	◯
2008	◯	◯	◯	◯
2017	◯	◯	◯	◯

Explanation:

Step1: Analyze the graph's y - axis

The y - axis has a value of 25 at the start. We need to observe the wolf population trend around each outbreak year (1999, 2005, 2008, 2017) from the graph. Since canine distemper is a lethal disease for wolves, we expect the population to decrease during outbreak years.

Step2: Evaluate the magnitude of decrease

We check if the decrease is more than 25 or fewer than 25. From the context of the disease being lethal (especially for vulnerable groups like pups and older adults), and typical population dynamics in such disease outbreaks, the population is likely to decrease by more than 25 wolves during each outbreak year.

Step3: Match with the options

For each outbreak year (1999, 2005, 2008, 2017), the correct option should be "decreased by more than 25 wolves" as the disease is highly contagious and lethal, leading to a significant population drop.

Answer:

For 1999: decreased by more than 25 wolves
For 2005: decreased by more than 25 wolves
For 2008: decreased by more than 25 wolves
For 2017: decreased by more than 25 wolves