What is a common reason researchers may underestimate the actual size of a population during a Mark Recapture study?

In a Mark Recapture study, the size of a population is estimated by capturing, marking, and then recapturing individuals to determine the proportion of marked ones in the total catch. If the time of the study is too short, it can lead to an inaccurate assessment of the population size. A short study duration may not allow for enough marked individuals to be recaptured or for sufficient time to elapse for the marked individuals to mix back into the population. This limited timeframe can create a skewed perception of how many individuals are present, as many may not have had the chance to be recaptured or have died, leading to an underestimation of the actual size.

Other options focus on aspects such as marking methods, population size, and environmental factors. While these can impact the accuracy of the study, a short time frame directly affects how representative the recapture data is, leading researchers to misjudge the population size.