in a mark/recapture study, an ecologist traps, marks, and releases 25 voles in a small woodland. A week late the trap is reset and she captures 30 voles. 10 of the 30 were marked. What is her estimate of the population?
2007-02-26 09:24:44 · 2 answers · asked by Anonymous in Environment
To estimate the population you usually use this equation:
Population size= (total caught 1st time)*(total caught a week later)/(number recaught)
So for these numbers that should be:
25*30/10=75
There are lots of things that could have interfered with this estimate, such as animals removing marks, animals that learn to like being trapped, animals that learn to be afraid of traps, how far the animals disperse in a week, any territorial behaviour ect. So you should try and use more than one method to estimate the population if possible, or at least repeat the mark/recapture study a few times.
2007-02-26 10:23:48 · answer #1 · answered by Ombry 3 · 1⤊ 0⤋
The Lincoln index is used to calculate pop size from mark and recapture studies. The formula is at this link:
2007-02-26 18:10:51 · answer #2 · answered by formerly_bob 7 · 1⤊ 0⤋