Question

The technique to mark, release and recapture is a practical method for

• A. Estimating the endangered species in a population.
• B. Estimating the population size of mobile animals
• C. Estimating the population size of umbrella species.
• D. Estimating the population size of indicator animals.

Hint:

Remember that mark-recapture relies on the "mixing bowl" assumption. You mark some, release them, and assume they mix evenly throughout the entire population. This can only happen if the animals move around. Therefore, the technique is fundamentally linked to the mobility of the species.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
The mark-release-recapture method is a widely used ecological technique to estimate the total size of a population when a direct count of all individuals is not feasible. The method involves capturing a sample of individuals, marking them in a harmless way, releasing them back into the population, and then capturing a second sample after a period of time.

Step 2: Detailed Explanation:
The core principle of this method is based on the Lincoln-Petersen index:
\[ \text{Population Size (N)} = \frac{(\text{Number marked in first catch}) \times (\text{Total number in second catch})}{(\text{Number of marked recaptures in second catch})} \] For this estimate to be accurate, several assumptions must be met, one of the most critical being that the marked individuals have had enough time to disperse and mix randomly with the unmarked population. This random mixing requires the animals to be mobile. The technique is not suitable for sessile (non-moving) organisms like plants or barnacles. While it can be applied to endangered, umbrella, or indicator species (options A, C, D), its fundamental requirement and most general application is for populations of mobile animals.

Step 3: Final Answer:
The most accurate and fundamental description of the utility of the mark-release-recapture technique is for estimating the population size of mobile animals. Option (B) is the best choice.