Thanks Conrad, Ted, Herb, Bob, Socrate and Eric.
I shot these about 15 years ago. There were less than one million birds there when I visited- but probably more than 50,000. I don't know if the lake was especially low, but we couldn't get very close to the birds because of all the mud (these were shot with a 400mm lens).
I saw a few wild flamingos in Florida 15+ years ago- too far away for photos, though. I assumed there were a lot more of them, but apparently not.
In the Galapagos Islands I saw a flock of less than one dozen- at a distance.
They seem to be extremely shy unless you have a Nat Geo budget to work with.
Charlie