STUDYING POPULATION PROBLEMS

1. On October 15, 1984 at the beginning of the squirrel-hunting season, biologists counted 95 gray squirrels in a 20-acre forest. On December 15, 1984, 42 gray were counted in the forest.
 a. What was the density of the gray squirrel population on October 15, 1984?
 b. What was the density of the gray squirrel population on December 15, 1984?
c. What factors could have affected the density of the population?
 d. What factors must have affected the density the most?

 2. In a certain city an 8-block area, 300 houses contained 1530 humans and an estimated population of 1800 rats. Then the Urban Renewal Commission razed the houses in the area and constructed 8 large apartment buildings. Following this development, 2880 humans and an estimated population of 200 rats occupied the area.
 a. Calculate the population density per block for rats before and after the development.
 b. What is the change in rat population density?
 c. What factors were probably most important in causing this change in the density of rats?
d. Calculate the population density per block for humans before and after the development.
 e. What is the change in human population density?
f. What factors were probably most important in causing this change in the density of humans?


3. On a range of 375 acres are a total of 1450 jackrabbits. During the following year studies indicate the rates for this population: Birthrate – 3625/yr Mortality – 2320/yr Immigration – 190/yr Emigration – 845/yr
a. Is the population of jackrabbits increasing or decreasing?
 b. Calculate the rate at which the population is changing (+ or - # jackrabbits/yr).
 c. Predict the population size at the end of four years.
d. What is likely to happen to the population of producers in this area during the four years? (BTW, jackrabbits are herbivores.)