ACT (Enhanced)ScienceEasy
A team of ecological researchers is monitoring the population of a specific bird species in a protected forest. They capture, band, and release 100 birds in the first year. In the second year, they capture 150 birds, and 10 of them are found to have bands from the previous year. Assuming no significant immigration or emigration, what is the estimated total population of the bird species in the forest?
- A1000 birds
- B2500 birds
- C1500 birds
- D2000 birds
Show answer & explanationAnswer & explanation
Correct answer: C. 1500 birds
The capture-recapture method is used to estimate population size. The formula is (M1 * M2) / R, where M1 is the number of individuals marked in the first capture, M2 is the total number of individuals captured in the second capture, and R is the number of recaptured marked individuals. (100 * 150) / 10 = 1500.
Why the other options are wrong
- A. This would result if the recapture count was 15, which is incorrect.
- B. This would result if the recapture count was 6, which is incorrect.
- D. This would be the result if 7.5 marked birds were recaptured, which is not the case.
Capture-Recapture Method
A technique used to estimate the population size of mobile animals. It involves capturing, marking, and releasing individuals, then later recapturing and counting the proportion of marked individuals.
- Used for estimating population size of mobile organisms.
- Assumes random mixing of marked and unmarked individuals.
- Assumes no significant births, deaths, immigration, or emigration between captures.
Memory trick: Marked Birds Return to Count