# Grassland - The mark and recapture method.

INTRODUCTION
The mark and recapture method is used in science to estimate the population size of mobile animals and other vertebrates. There are many methods used and each is more accurate under different circumstances. The method used in this assignment is the
Lincoln - Peterson Method. How this method works is that a number of individuals in a population are captured and marked in some way that is identifiable and then released.

### METHOD

1. A site, of 60m long, is chosen at random for the investigation.
2. The site is split in to 6 sections and assigned to each group.
3. Groups have 15 minutes to capture a random sample of the population, mark individuals, and release them so that they remix with the rest of the population.
• When animals are marked, precautions are made to use methods that will not harm the animal in any way or that would jeopardize its chances of survival once released again. For example: when working with snails, they are given a small dot of polish on their shell.
1. After 24 hours, groups then capture another sample of animals in the same area for 15 minutes.
2. Captured animals are counted and the number that are marked, as well as those that are not marked, are recorded.
• It is expected that if the population is large there would be relatively few animals recaptured. On the other hand, in a small population there should be a large number of animals recaptured.

RESULTS

Individual group results

Total data obtained.

STATISTICAL ANALYSIS

Lincoln - Peterson Method

In theory, the ratio of the total population (N) to the number of marked individuals (M) is equal to the ratio of the number captured (n) at a later date to the number that were recaptured (R) on the later date. This equation can be rearranged to the following equation.

In essence, by knowing the number of individuals captured and marked on the first day (M), the number captured on the second day (n), and the number recaptured on the second ...