The total number of the species of the same kind in a given habitat is

Explanation

Population size is simply the total count of all individuals of one species in a habitat. If a forest has 500 rabbits, the rabbit population size is 500. This number tells us how many organisms are living in that area.

Population density measures how crowded the organisms are in a space, like 10 rabbits per square kilometer. Population frequency is not a standard ecological term. Population growth rate shows how fast the population is increasing or decreasing over time.

Scientists count population size to understand if a species is healthy or struggling. Large population sizes usually mean the habitat provides enough resources. Small population sizes might signal problems with food, space, or predators.