Question

Given this bird population growth data, answer the followign questions:

1) Explain why you think the population grew in the pattern it did

2) Model the population as closely as possible using the logistic equation. Lowever to do so, you'll need to predict the intrinsic rate of increase and carrying capacity. Estimate these vales as must as possible. Report the estimated R and K and graph 1) the populations (both modeled and real on the same graph) against time, 2) R vs. population size (for both) and 3) dn/dt vs. population size (for both). There will be 3 graphs total.

3) How close do you feel your best fit model explains teh data? You will find you never find a series of values that will exactly match the actual population. Thinking about the assumptions of logistic growth, explain why this is probabily the case.

4) Suppose I told you that birds can lay 4 eggs. Assuming equal sex ratios, each female has the potential to successfully hatch 2 young females. Assuming no density dependent constraints, this tells us that birds have a ? max = 2 or an Rmax = 1 (continuous rmax = 0.693). Using the theta-logistic equation with R = 1, remodel the population by tinkering with values for carrying capacity K and curvilinear term theta. As with part B, use 3 graph types to help model the data. What values best model the data? Given the now apparent curvilinear structure to the growth of the population, are birds an r selected or a K selected species? How can you tell?

1961 56 1941 1962 60 1942 1963 67 1943 61 1344 1965 59 1945 135 50 196 53 1947 1968 68 1949 1970 1950 1971 76 10 197 37 15 1973 89 1953 1974 1954 1975 100 1956 50 19 / 1958 50 82 1980 95 1960

Answer 1

1). As per the given data, we can observe that the bird population has increased from the year 1940 to 1980. This may be due to,

a). Increased availability of food resources and migration from other regions

b). Decreased predation.

c). Decreased mortality