If you’ve been captivated by the starling murmurations this winter, you may be wondering how many birds are in those vast swirling flocks. There’s no easy way to count them on the wing, but you if you can get a decent photo with the bulk of them in the frame, there’s a simple technique to get a rough estimate that will give you a good idea of numbers
So, here’s a photo of a small murmuration I took locally. As you can see, I overlaid a grid on the photo. The simplest way to estimate bird numbers is to zoom in on a representative looking square and count them in just that one square. An average looking square in my photo has 70 or so birds in it. There are a few squares that have no birds (ignore those) some that look like they have just a couple of dozen and some that are much denser, so perhaps 100 or so.
So, counting all the squares with birds and multiplying by 70 would give you a rough number. A slightly more accurate way, might be to count only the average looking squares, multiply that number by 70. Then pick a sparse square and do a count, 30, say, multiply that by the number of sparse squares and add to the earlier tally. Then, do the same with the more densely populated squares. You could tally the sparse and dense as an average by counting how many squares and halving it and adding that instead. Lots of ways to do it.
While I was watching this murmuration, I guesstimated about 3000 birds in the flock. Using the method above the number comes out at double that! About 6000 birds, just in this frame. There were actually more that aren’t in the shot!
I did the same sort of counting at RSPB Ouse Fen at Earith in March 2024 where a friend had suggested the murmurations contained about 100,000 birds. The evening I was there the sky was filled with starlings. I took a lot of photos to get all the sections of this vast flock. I then did a grid count as above. I got a much larger number – 500,000 to 750,000. There may have been a few more. That’s the biggesst number of birds I’ve seen in one place!