What is the Lincoln Peterson equation?

N = (n1 + 1)(n2 + 1) -1 (m2 +1) Page 2 where N is the Lincoln-Petersen estimate of total population size, n1 is the number of marked animals released into the population, n2 is the total number of animals in the second sample, and m2 is the number of marked animals in the second sample (i.e. recaptures).

What are the disadvantages of the capture mark recapture method?

They offer the advantage that accuracy does not depend on an assessment of the amount of habitat; their disadvantage is that accuracy does depend on capturing a large proportion of the population.

Is the capture-recapture method accurate?

Capture-recapture methods are more likely to produce a biased estimate of the population size if one source (or combination of sources) captures very few cases. However, the assumptions made when using simple capture-recapture methods are unlikely to be true in epidemiological studies.

How do you do a capture mark-recapture?

The basic idea is that you capture a small number of individuals, put a harmless mark on them, and release them back into the population. At a later date, you catch another small group, and record how many have a mark.

Who created the mark and recapture method?

The first person to introduce the K-sample capture-recapture method was Schnabel in 1938(12), in the context of fishing in a lake. She made the usual assumptions about the sampling and the marking processes such as each sample is a simple random sample and animals do not lose their tags.

What is Lincoln Petersen estimate?

Lincoln–Petersen estimator The Lincoln–Petersen method (also known as the Petersen–Lincoln index or Lincoln index) can be used to estimate population size if only two visits are made to the study area. This method assumes that the study population is “closed”.

When would mark and recapture not work?

The mark must not wash off or wear away. There must be no immigration into or emigration out of the population. There must be no mortality between the mark and recapture times. The marking experience must not make an individual more or less likely to be recaptured.

What is capture recapture technique?

The method involves capturing a number of animals, marking them, releasing them back into the population, and then determining the ratio of marked to unmarked animals in the population.

What is wrong with the mark recapture method?

One disadvantage of this method is that recapture data is typically lost when capture and recapture occur during the same pooling interval. Longer pooling intervals result in greater loss of information about recapture.

How does capture mark recapture ( CMR ) work?

Capture-Mark-Recapture (CMR) can be viewed as an animal survey method in which the count statistic is the total number of animals caught, and the associated detection probability is the probability of capture.

How is the capture recapture method of sampling used?

Capture – Recapture Method of Sampling. Capture – Recapture is a common method used to estimate the size of a population by sampling. Biologists and ecologists use this method extensively to estimate wild animal populations. • Step 1: Capture a sample of the animal you want to count in the area you want to know about.

What are the assumptions in Mark and recapture?

Assumption 1. During the interval between the preliminary marking period and the subsequent recapture period, nothing has happened to upset the proportions of marked to unmarked animals (that is, no new individuals were born or immigrated into the population, and none died or emigrated).