Capture Recapture

Front

What is the Capture-Recapture method used for?

Back

The Capture-Recapture method is used to estimate the population size of a species in a given area.

Front

How do you estimate the total population using the Capture-Recapture method?

Back

The estimate is calculated using the formula: (Number of marked individuals in the second sample / Total number of individuals in the second sample) = (Number of marked individuals in the first sample / Total population size).

Front

In a Capture-Recapture study, what does marking an individual allow researchers to do?

Back

Marking allows researchers to identify previously captured individuals in subsequent samples.

Front

If 50 crabs are captured and 5 are marked in a second sample of 25, how do you estimate the total crab population?

Back

Using the proportion of marked crabs in the second sample, the estimate is: (50 marked crabs / Total population) = (5 marked crabs / 25 caught), leading to an estimated population of 250.

Front

What is the significance of the sample size in Capture-Recapture studies?

Back

A larger sample size generally leads to more accurate estimates of the population size.

Front

What assumptions are made in the Capture-Recapture method?

Back

Assumptions include that the marked individuals mix evenly with the unmarked population and that there are no births, deaths, immigration, or emigration between captures.

Front

What is the formula for estimating population size in Capture-Recapture studies?

Back

The formula is: N = (M * C) / R, where N is the estimated population size, M is the number of marked individuals, C is the total number of individuals captured in the second sample, and R is the number of marked individuals recaptured.

Front

What does 'N' represent in Capture-Recapture calculations?

Back

'N' represents the estimated total population size of the species being studied.

Front

Why is it important to release marked individuals back into the population?

Back

Releasing marked individuals allows them to mix with the unmarked population, which is essential for the accuracy of the Capture-Recapture method.

Front

What is a potential source of error in Capture-Recapture studies?

Back

A potential source of error is if marked individuals are more likely to be recaptured than unmarked individuals, leading to biased estimates.