PRO: Quadrats work well for observing changes to whole populations over time, including distribution patterns, nesting and overall health. Some study techniques do not work with quadrats, however. For example, capture-recapture techniques that allow researchers to study individual animals do not work with quadrats because even slow-moving animals can move out of the study boundaries between sample periods.
CON: Despite the relative ease of designing quadrat studies, it is possible to introduce errors into a project. Quadrats that are too large, too small or spaced inappropriately often result in errors. For example, larger species require larger plots. Randomly spaced quadrats that are too small might miss too many individuals, resulting in under-representative estimates of population size.