Tagging Animals Is Indicative Of Which Type Of Method To Determine Population Size?

Mark-Recapture

The Marker-Recapture technique is used to estimate the size of a population where it is impractical to count every individual. The basic idea is that you lot capture a minor number of individuals, put a harmless mark on them, and release them back into the population. At a afterwards appointment, you catch another small group, and tape how many have a marking. In a small population, you lot are more likely to recapture marked individuals, whereas in a large population, you are less likely. This can be expressed mathematically using the equation below.

N = (One thousand*C) / R

N = estimated N umber of individuals in the population

M = number of individuals captured and M arked

C = total number C aptured the second time (with and without a mark)

R= number of individuals R ecaptured (those with a mark)

Example: Let's say that your neighborhood has a population of snails, which come up out onto the sidewalk when the sprinklers come on, and the remainder of the time they hide in the vegetation. If you catch 20, and mark them and, and then, a week later, after they accept had a chance to disperse into the population, you catch xv, and six accept marks on them, what is the estimated size of the population?

N = (G*C) / R

North = (20 * 15) / 6

North = fifty

Assumptions: If any of the following assumptions or conditions are violated, it may touch on the accuracy of the population guess.

1. If no marked individuals are recaptured, R = 0 and your upshot is undefined. Mark more individuals and try once again.
2. The marking technique must not damage the private or affect its survival by predation.
3. The mark must not launder off or wear away.
4. At that place must be no immigration into or emigration out of the population.
5. In that location must be no mortality betwixt the mark and recapture times.
6. The marking feel must non make an private more than or less probable to exist recaptured.

Questions:

1. Describe how a mark might bear upon the survival of an individual. Would that cause an over- or nether-estimate of the population size?
2. What if the marker done off the animal? Would that crusade an over- or under-estimate of the population size?
3. What if many unmarked individuals are immigrating into the population? Would that cause an over- or under-estimate of the population size?
4. What if many of the marked individuals are emigrating from the population? Would that crusade an over- or under-estimate of the population size?
5. What if most of the marked individuals die earlier the recapture is conducted? Would that cause an over- or under-estimate of the population size?
6. Can you propose some reasons why an individual might be more likely than boilerplate to be recaptured? Would that crusade an over- or nether-guess of the population size?
7. Can you think of a reason why an individual might be less likely to be recaptured? Would that crusade an over- or under-guess of the population size?

References:

https://www.youtube.com/watch?v=240806aPHVg

https://en.wikipedia.org/wiki/Mark_and_recapture

Source: https://www2.nau.edu/lrm22/lessons/mark_recapture/mark_recapture.html

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