The mark and release method can be used to estimate penguin population size. Let's say a researcher traps 20 penguins in a specific population. These penguins would be tagged and released. After enough time has passed to allow those 20 penguins to redistribute themselves into the population, the researcher captures another sample of 25 penguins. There are 12 previously tagged penguins in this second sample. Using the equation to estimate population size using the mark and release method, the total number of tagged penguins (20) are then divided by the proportion of tagged penguins from the second sample (25/12) in order to give an estimate of total population size (approximately 42).