4. Suppose that an ecologist is studying the population of the golden-throated song sparrow and he finds the relationships illustrated in the graph below between the hatch and death rates and population, given that the existing food supply, level of predation, and so on are fixed.
a) What will happen if the population is at level a? At level b? At level c?
b) Show on the graph what will happen if the food supply increases.
c) Explain what will happen on the graph if, due to an increase in the use of pesticides, fewer eggs hatch.
d) Explain what will happen on the graph if the number of predators increases.
e) In what ways do the mechanics of this model resemble the mechanics of the supply and demand model?