Question

Population densities are not easy to measure in natural populations, so ecologists have designed different methods to estimate densities. Complete the sentences with the correct terms to describe these different estimating methods.

a) The ________________ method involves capturing, marking, and recapturing individuals.
b) In the ________________ method, researchers count the number of individuals in a sample area and extrapolate to the entire population.

Answer 1

The methods to complete the sentences are 'mark and recapture' and 'quadrat.' Mark and recapture is used for mobile organisms, and quadrat for immobile organisms, such as plants.

Step-by-step explanation:

Ecologists use various methods to estimate population densities in natural populations. The answer to complete the sentences is:

1. The mark and recapture method involves capturing, marking, and recapturing individuals.
2. In the quadrat method, researchers count the number of individuals in a sample area and extrapolate to the entire population.

For mobile organisms such as mammals, birds, or fish, the mark and recapture method is commonly used. This involves marking a sample of captured animals, releasing them back into the environment, and then later recapturing some to estimate the entire population size. For immobile organisms like plants, the quadrat method is effective. This involves marking off square areas within a habitat and counting the individuals within these quadrats at several random locations to estimate the population size and density.