Question 1: A researcher captures 150 animals, tags them, and releases them. Later, they capture 120 animals, of which 30 are tagged. Using the Capture-Recapture formula, estimate the total population.

Answer: 600

Question 2: If 200 animals are tagged initially and in a second catch, 50 animals are caught with 10 tagged, what is the estimated population?

Answer: 1000

Question 3: In a study, 180 animals were tagged. Later, 200 animals were caught, with 40 tagged. Calculate the estimated population.

Answer: 900

Question 4: Explain why the Capture-Recapture estimate might be inaccurate if animals are trap-shy or trap-happy.

Answer: Animals avoiding traps (trap-shy) or being attracted to traps (trap-happy) can skew the number of animals caught, leading to overestimation or underestimation of the population.

Question 5: Construct a scenario where the estimated population is 500, with 150 animals tagged initially, and 75 animals caught in the second catch, with 30 tagged. What is the number of animals caught in the second catch?

Answer: 75

Question 6: Plot the graph of the estimated population (y-axis) against different numbers of tagged animals initially caught (x-axis) for a fixed second catch of 60 animals, with initial tagged numbers of 50, 100, 150, and 200.

Answer: Students will draw a graph; key points are at (50, estimated population), etc.

Question 7: A population estimate using Capture-Recapture is 800. If initially 200 animals were tagged, and 80 animals were tagged in the second catch of 160 animals, what is the size of the second catch?

Answer: 160

Question 8: Identify and correct the mistake in this estimation: 'If 100 animals are tagged, 50 are caught in a second catch, with 10 tagged, then the population is estimated as 500.'

Answer: The correct estimate is (100 x 50) / 10 = 500, so the calculation is correct. But if the number caught in second catch is not accurate or animals are not equally likely to be caught, the estimate can be inaccurate.

Question 9: Estimate the population if 180 animals are tagged initially, 200 are caught in the second catch, with 50 tagged. Then, calculate the error if the true population is 900.

Answer: Estimate = (180 x 200) / 50 = 720; Error = 900 - 720 = 180

Question 10: A researcher captures 250 animals, tags them, and later captures 300 animals, with 60 tagged in the second catch. What is the estimated population? Is this estimate likely to be accurate if animals tend to avoid traps?

Answer: 1250; likely less accurate due to trap-shyness