Final answer:
The mark and recapture method estimates population size by marking a sample of animals, releasing them, and then capturing a second sample to see how many marked animals appear. This ratio helps estimate population size, which is then divided by the area to find population density.
Step-by-step explanation:
The method of mark and recapture is a tool used by biologists to estimate the population size and density of wildlife, such as spotted gliders, in a given area. This technique involves capturing a sample of animals, marking them, and then releasing them back into the environment. After some time, a second sample is captured, and the ratio of marked to unmarked individuals in this sample is used to estimate the total population size.
The formula for population estimation using this method is M/N = m/n, where M is the total number of animals marked and released in the first sample, N is the total population size (an unknown we solve for), m is the number of marked individuals found in the second sample, and n is the total number of animals captured in the second sample. Once the population size (N) is estimated, it is divided by the area of the habitat to calculate the population density. This method assumes a random distribution of individuals within the area and that marked animals have thoroughly mixed back into the population.
For example, if 80 spotted gliders are captured, marked, and released, and in a later capture, 100 gliders are caught with 20 being marked from the original capture, the estimated population size (N) can be calculated and then used to determine the population density per square kilometer.