ML531171581
Contributor
Date
Location
- Age
- Not specified
- Sex
- Not specified
Media notes
Photo taking for sole purpose of determining how close my estimate in the field was. I was off by a factor of 1/2 in under estimating the number.
Observation details
Flyovers of three separate flocks originally estimated at 2500, 1200, and 1500 individuals. I purposely took photos of the one largest flock (in 2 frames) to calculate the number per square inch and then get total # square inches. I determined that there is a total of 180 sq. combined in the two frames with an average of about 30 birds per square inch. Thus the largest flock should have been 5000, not 2500- I grossly under estimated the number. Assuming I did the same on the other two flocks (i.e. 2400 and 3000), I have adjusted my total to 10,400- exactly 2x what I estimated originally. This exercise was undertaken to see how close my field estimate was compared to calculating the number in my photos. When birding with Van Remsen, he noted that I generally under estimate large flocks of birds, especially icterids. This exercise confirms his observations.
Technical information
- Model
- COOLPIX P950
- ISO
- 100
- Focal length
- 67.8 mm
- Flash
- Flash did not fire
- f-stop
- f/6.3
- Shutter speed
- 1/1600 sec
- Dimensions
- 4608 pixels x 3456 pixels
- Original file size
- 3.55 MB