Final answer:
To quantify well-camouflaged organisms, the mark-recapture method is used, allowing ecologists to estimate the population size and density of mobile species.
Step-by-step explanation:
The best way to quantify well camouflaged organisms is by using the mark-recapture survey method. This approach is especially effective for mobile organisms, such as mammals, birds, or fish, which might possess natural camouflage aiding them in blending with their environment. Initially, scientists capture a sample of these animals, then mark them with tags, bands, paint, or other body markings before releasing them back into the wild. The marked individuals are given time to mix with the rest of the population. After this, a subsequent sample is captured, from which the proportion of marked to unmarked individuals is used to estimate the total population size.
The mark-recapture method provides an estimate of both population size and density, thus answering both the student's question and the review question regarding which method informs an ecologist about the size and density of a population. It is important to use a method that can capture the elusive nature of camouflaged organisms, and mark-recapture is well suited to this task.