Using PopEcoLab Carrying Capacity for the Population of Sparrows Leaving all parameters (figure 1) at their default values, the habitat being studied has a carrying capacity of 1,250 brown sparrows. The experiment was ran over 100 years (figure 2.1) and 200 years (figure 2.2), but the results remain the same. This is no surprise since default environmental conditions are kept constant and the experiment did not take into consideration predators and other competitors for resources.