Capture, Mark &

RecapturePopulations Estimates

AP Environmental Science

C-M-R• How do we estimate the number of animals out there?

Elk? Wolves?

Lincoln-Petersen Technique

• 1. Capture animals and mark all that you caught• 2. Release these animals• 3. Capture again and count the number of marked animals.

What do we need to capture and mark

animals• Think….How are fish caught?

How are they marked or tagged? How are birds caught? Marked?

Male vs Female

Male

Female

Large Oviposit

or

Lincoln Petersen Model

• Population Estimationn1 = m2 or N= n1 x n2N n2 m2

Closed model (meaning that population is constant during the time of experiment.)

Variables IdentifiedN = estimate of population

sizen1 = # of animals marked and

released first timen2=# of animals captured

second timem2=# animals with marks at

the 2nd session.