Estimating numbers in flocks of birds is a skill that birders need to practice, but we rarely get a chance to test ourselves. We see a flock, guess the total number, and write it down. We might be off by a large margin, but we’ll never know.
Here is a quiz (and more to come) that will give you a chance to test your accuracy. These are lentils, photographed against a white background, but they simulate birds pretty well, I think.
One estimating technique you can try is to count the “flock” in segments. That is, count ten to see what a group of ten looks like, then superimpose that group across the flock, counting in groups of ten. Or you can just “eyeball” the flock of lentils and take a guess. Good luck, and feel free to offer suggestions or encouragement in the comments.
Test your number sense
Question 1 |
45 Hint: way too low | |
60 Hint: too low | |
100 | |
140 Hint: a little high | |
180 Hint: too high |
Question 2 |
50 Hint: too low | |
80 Hint: close, just a little low | |
100 | |
120 Hint: close, just a little high | |
150 Hint: too high |
Question 3 |
60 Hint: too low | |
90 Hint: too low | |
110 Hint: a little low | |
150 | |
190 Hint: a little high |
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This was good!! Keep em coming. & for future reference do not ask me to count birds this fall !!
Interesting… this is definitely a skill I could use some practice with.
Thanks for this, awesome idea… Anxious to see the other quizzes that will be arriving- the practice is needed & very much appreciated!!
Good practice. Will be useful with CBCs coming up. Question #2 may have a glitch.
Thanks Mike, The quiz works fine for me. Let me know if you still have a problem with it.
ARBIB, R. 1972. On the art of estimating numbers. Am. Birds 26:706-712
Thanks, Mr. Sibley. I also experienced a glitch w/ question 2. When I clicked on D there was no response. Then when I tried E a checkmark appeared.
These are great exercises, and I really need to practice this skill. This is a cool way to do it.
My only quibble: What level of precision is necessary? To my mind, there is no significant difference between the numbers 90 and 100 in this context. Even 100-120 are within the expected margin of error, I would think. If my estimates of birds in flight were regularly within 50% of the actual number, I’d call myself skilled enough. Am I setting the bar too low?
Hi Tim, Thanks for the feedback. I agree, if you’re getting within 50% consistently that’s pretty good. I did try to avoid making these quizzes too “nit-picky” with answer choices as close together as 90 and 100, so I’ve just fixed that one. I also added “hints” that show up to give instant feedback on which way you missed, as I think that is helpful also.