Lincoln Index

Formula to estimate the size of the population

N = n1 x n2/n3

N

total size of the population

n1

the size of the first sample

n2

the size of the second sample (marked and unmarked)

n3

the number of marked individuals recaptured in the second sample

1st assumption of Lincoln Index

the population of organisms must be closed, with no immigration or emigration.

2nd assumption of Lincoln Index

the time between samples must be very small compared to the lifespan of the organism bein sampled.

3rd assumption of Lincoln Index

the marked organisms must mix completely with the rest of the population during the time between the two samples.

When estimating an organism's population size, why is it important that the time between first and second samples be a short time compared to the organism's lifespan?

It is important because the organism from the population might pass away and the population decreases. Therefore, the estimation might be incorrect.

Why is it important to be able to determine population size?

The ability to determine population size it important to describe the current status of the population and for making the prediction about how it could change in the future. so that they can monitor endangered/extinct organisms.

Three organisms that could be examined using lincoln index

whales, turtles, snails

Why would a large pond tend to have fewer recaptures than small pond?

The large pond will tend to have a fewer recaptures than a sall pond, because it has more goldfish so the probability decreases to have recaptures.

Which of the following examples do you think reflects the largest population?

large first sample, large second sample, small recapture

Which reflects the smallest?

small first sample, small second sample, large recapture