SCIENTIFIC THINKING Another hypothesis for snowshoe hare population cycles proposes that they are caused by sunspot activity. According to this hypothesis, sunspot activity affects the chemicals present in the plants eaten by hares, which in turn affects the quality of the food. What testable predictions are generated by this hypothesis?

Describe the factors that might produce the following three types of dispersion patterns in populations.

Burmese pythons (Python molurus bivittatus) are constricting snakes that can reach enormous sizes (up to 7 meters in length). They are native to Southeast Asia but were released into southern Florida from the pet trade. Many other snakes occur naturally in this area. Are the introduced pythons a problem?Researchers hypothesize that the severe winter of 2010 caused the decline in the number of pythons encountered that year. Is cold weather typically a density-dependent factor or a density-independent factor? Explain the difference.

The mountain gorilla, spotted owl, giant panda, snow leopard, and grizzly bear are all endangered by human encroachment on their environments. Another thing these animals have in common is their K-selected life history traits. Why might they be more easily endangered than animals with r-selected life history traits? What general type of survivorship curve would you expect these species to exhibit? Explain your answer.

Burmese pythons (Python molurus bivittatus) are constricting snakes that can reach enormous sizes (up to 7 meters in length). They are native to Southeast Asia but were released into southern Florida from the pet trade. Many other snakes occur naturally in this area. Are the introduced pythons a problem?The data in the graph show the number of pythons that were encountered, not the total number of pythons in the population. Design a mark–recapture experiment to estimate the total population size of pythons, and list at least twoassumptions you would be making in your experiment.

Burmese pythons (Python molurus bivittatus) are constricting snakes that can reach enormous sizes (up to 7 meters in length). They are native to Southeast Asia but were released into southern Florida from the pet trade. Many other snakes occur naturally in this area. Are the introduced pythons a problem?A life table would help researchers make predictions about python population growth. If you were to track a cohort of pythons over time to construct a detailed life table, what kind ofdata would you want to collect?

Many people regard the rapid population growth of developing countries as our most serious environmental problem. Others think that the growth of developed countries, though slower, is actually a greater threat to the environment. What kinds of environmental problems result from population growth in (a) developing countries and (b) developed countries? Which do you think is the greater threat? Why?

Burmese pythons (Python molurus bivittatus) are constricting snakes that can reach enormous sizes (up to 7 meters in length). They are native to Southeast Asia but were released into southern Florida from the pet trade. Many other snakes occur naturally in this area. Are the introduced pythons a problem?Pythons are generalist predators, consuming a wide variety of prey including birds, mammals ranging from rodents to deer, and alligators. A road survey showed a 99 percent decrease in the frequency of raccoon and opossum observations within python areas from 2003 to 2011. Rabbits and foxes have also disappeared from the area. Do you think food availability limits, or could limit, the carrying capacity of Burmese pythons in the Everglades?

Burmese pythons (Python molurus bivittatus) are constricting snakes that can reach enormous sizes (up to 7 meters in length). They are native to Southeast Asia but were released into southern Florida from the pet trade. Many other snakes occur naturally in this area. Are the introduced pythons a problem?The range of Burmese pythons in Florida is expanding rapidly. List at least one abiotic factor and one biotic factor that might limit the range of pythons.