What is the most common method used to count a large species population

Ecologists

Explanation

often estimate the size and density of populations using quadrats and the mark-recapture method. A population can also be described in terms of the distribution, or dispersion, of the individuals that make it up. Individuals may be distributed in a uniform, random, or clumped pattern.

Sampling

Explanation:

In research terms a sample is a group of people, objects, or items that are taken from a larger population for measurement. The sample should be representative of the population to ensure that we can generalize the findings from the research sample to the population as a whole.