Sunday, January 11, 2015

Counting Birds...Estimating and Using Photoshop

This is a follow-up to a blog posted several days on a large waxwing flock (http://goo.gl/QCwMFX). In the past, I've just estimated the flock size without using a camera. The immediate photo below illustrates a traditional method of estimation used "live". One applies a "block" (really an area measure) of known quantity to the entire flock as quickly as possible. In this case I used 25 birds as the block...it seems about right. So, I wind up with 5 groups of 25 or roughly 125 birds. In larger flocks 25-bird-groups would be too small.

The bottom photo is an actual count of the birds using Adobe Photoshop CC. You use the Count Tool (one of a couple methods); this tool is a dropdown under the Eyedropper Tool. It is somewhat tedious manually clicking on each bird image, but it is very accurate. The count is 147; did you come up with that number? My estimate is 85% of what was recorded by camera. Do you think that is good enough? Try estimating the birds at your feeders for practice; use your camera as the check...good counting :-)