Capture-Recapture

• What method is used to estimate the population size of motile organisms?

  Mark-release-recapture method
• What are the four parts of the lesson on the mark-release-recapture method?

  Method, ethics, assumptions, calculation
• What type of organisms does the mark-release-recapture method estimate?

  Motile organisms
• What is the first step in the mark-release-recapture method?

  Capture an initial sample and mark them
• What is an ethical way to capture insects for the mark-release-recapture method?

  Using pitfall traps
• Why is it important for the marking method to be weather resistant?

  To prevent the mark from washing off
• What should be provided inside larger box traps for captured animals?

  Food and water
• Why must animals be left for a period of time after release?

  To allow random dispersion in their habitat
• What data must be collected during the second sample capture?

  Total number captured and marked individuals
• What is the purpose of the calculation in the mark-release-recapture method?

  To estimate the size of the entire population
• If 20 butterflies are initially caught and 22 are recaptured with 9 marked, what is the population estimate?

  48.89, rounded to 49
• What is a key ethical consideration when marking animals?

  It must not cause permanent harm or pain
• What type of paint should be used for marking animals?

  Non-toxic and weather resistant
• Why should the marking not increase predation risk?

  It should not disrupt their camouflage
• What assumption is made about population size during the mark-release-recapture method?

  No new births, deaths, or migration
• What is assumed about the redistribution of animals after release?

  They redistribute evenly in their habitat
• Why might the estimate from the mark-release-recapture method be inaccurate?

  Assumptions about population dynamics may not hold
• What might cause animals to huddle in one area instead of redistributing evenly?

  Proximity to food or water sources