When organisms face limiting factors, they show logistic growth (S-shaped curve, curve B: Figure below ). Competition for resources like food and space cause the growth rate to stop increasing, so the population levels off. This flat upper line on a growth curve is the carrying capacity. The carrying capacity (K) is the maximum population size that can be supported in a particular area without destroying the habitat. Limiting factors determine the carrying capacity of a population. Recall that when there are no limiting factors, the population grows exponentially. In exponential growth (J-shaped curve, curve A: Figure below ), as the population size increases, the growth rate also increases.
Mark had always wanted to go on a safari now that he was here he was amazed at the  huge herds of animals on the African Savannah but there is only grass to feed them part of the year and there are predators that hunt them for food.
Will larger herds eat more or less grass?