How can I estimate the number of individuals in a large group of animals?
If you are looking at large groups of animals, such as a colony of black-tailed prairie dogs, a migrating flock of robins, or a school of salmon, you may have a hard time estimating the total number of individuals you are seeing. Here are two ways to make an estimate of the total number of individual animals: • If you can see the whole group at once (such as a far away flock, or a relatively stationary herd of animals), try counting a small section of the total group (anywhere from 10 to 50 individuals). Then estimate the space those individuals take up. For example, 30 robins in a far away flock take up an area the size of my fist when I hold it in front of my face. I will then see how many of these fist-sized areas (or blocks) it takes to visually cover the whole flock. Let’s say there are 22 blocks. My estimate is then 30 individuals per block, multiplied by 22 blocks, for a total of 660 individuals. You might also consider taking a picture of the group of animals, and estimating or
