1. MEASURING POPULATIONS pp. 383-387

2. birth rate: # of births per given time death rate: # of deaths per given time Growth rate: the amount a population size changes in a given time

3. GROWTH RATE Net reproduction r = birth rate – death rate Growth rate= r = b – d/ total population If the value is +, the population is growing If the value is -, the population is declining

4. EXAMPLE of per capita rate In a rat cage containing 400 rats, 100 rats are born and 40 die. Growth rate= r = (b – d) / total population r= #of births - #of deaths total population r= 100 - 40 = 60 = 0.15 400 400

5. What the per capita means You can estimate the next year’s population size EX. original population + change = new pop. 60 + 400 = 460 How big would the population be the next generation? 460 x 0.15 = 69 69 + 460 = 529