Mark-Release-Recapture Method Concepts

Dr. Arpita introduces the mark-release-recapture method, also known as the Lincoln Index, for estimating the size of populations, particularly those of smaller, mobile organisms. The method involves capturing, marking, and releasing a sample of individuals, then recapturing another sample to estimate the total population size. Assumptions include equal mixing and capture probability. Errors can occur if marked animals are more or less likely to be recaptured. Practical considerations include careful marking to avoid affecting survival. The lecture concludes with an invitation for questions.

What is the primary purpose of the Mark-Release-Recapture method?

• To track migration patterns of large animals

• To estimate the size of populations of smaller, mobile organisms

• To study the behavior of stationary organisms

• To identify new species in a habitat

In the Mark-Release-Recapture method, what does the variable 'm' represent?

• The total population size

• The number of marked animals initially captured

• The number of unmarked animals recaptured

• The number of animals that emigrated

Why is it important to allow marked animals enough time to mix with the population?

• To ensure a random distribution among the population

• To increase their chances of survival

• To ensure they forget their original location

• To allow them to reproduce

How is the total population size 'n' calculated in the Mark-Release-Recapture method?

• By dividing the number of marked animals by the number of recaptured animals

• By adding the number of marked and unmarked animals

• By multiplying the number of marked animals by the number of recaptured animals

• By multiplying the number of marked animals by the total number of animals captured and dividing by the number of recaptured marked animals

What assumption is made about the marked animals in the Mark-Release-Recapture method?

• They will not survive until recapture

• They have the same chance of being recaptured as unmarked animals

• They have a higher chance of being recaptured

• They will not mix with the unmarked population

What could lead to an underestimation of the population size in this method?

• Marked animals being predated

• Marked animals being more active and entering traps more frequently

• Marked animals being less active

• Unmarked animals avoiding traps

What is a potential consequence of marking animals too boldly?

• Decreased chance of entering traps

• Increased mixing with the population

• Decreased chance of survival due to predation

• Increased chance of recapture

Why is it important that the ratio of marked to unmarked animals leaving the population remains constant?

• To decrease the number of unmarked animals

• To ensure the population size is overestimated

• To maintain the accuracy of the population estimate

• To increase the number of marked animals

What should be considered when marking animals in this method?

• The mark should not affect the animal's survival chances

• The mark should be permanent

• The mark should be visible only to humans

• The mark should be colorful

What happens if the marked animals do not mix well with the population?

• The population size will be accurately estimated

• The method will not be affected

• The population size will be underestimated

• The population size will be overestimated