Petersen capture-recapture formula (AQA GCSE Statistics): Flashcards
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What is the Petersen capture-recapture method?
What is the Petersen capture-recapture method?
A method to estimate wildlife population sizes.
What does the formula N = (M × n) / m represent?
What does the formula N = (M × n) / m represent?
It estimates total population size using marked samples.
If 50 animals are marked, 100 recaptured, 10 marked found, N?
If 50 animals are marked, 100 recaptured, 10 marked found, N?
N = (50 × 100) / 10 = 500 total animals.
What is a key assumption of the capture-recapture method?
What is a key assumption of the capture-recapture method?
The population must remain closed during the study.
Why must marked animals be equally catchable?
Why must marked animals be equally catchable?
To ensure unbiased results in the recapture sample.
If 80 marked, 200 recaptured, 20 marked found, N?
If 80 marked, 200 recaptured, 20 marked found, N?
N = (80 × 200) / 20 = 800 total animals.
What happens if marks are not visible during recapture?
What happens if marks are not visible during recapture?
It can lead to inaccurate population estimates.
What is the first step in the capture-recapture method?
What is the first step in the capture-recapture method?
Capture and mark a sample of the population.
If 30 marked, 60 recaptured, 15 marked found, N?
If 30 marked, 60 recaptured, 15 marked found, N?
N = (30 × 60) / 15 = 120 total animals.
What should you check after calculating N?
What should you check after calculating N?
Ensure N is larger than both sample sizes.