A recent comment thread on Facebook about absurdly high counts of some species in the eBird database got me curious. Who has seen the most Green Herons at one time? Painted Buntings? Gyrfalcons? What is the most of any one species that has ever been reported at one time? And how reliable is this data? Once you start down such a rabbit-hole it is difficult to stop the plunge into full on data-nerd mode.

Before I continue and get into some interesting numbers I should point out that the high counts listed here are all the highest numbers ever reported to eBird and confirmed by an eBird reviewer. Obviously, not all bird records have been reported to eBird. Also obvious is that there has to be some level of trust for some of these records to be considered accurate. Counting huge numbers of birds is very difficult and the general goal of observers is to at least get within an order of magnitude, which, when the numbers are ten or a hundred is relatively easy but when you are talking about 100,000 birds or a million birds things can get a bit more difficult. After all, have you ever counted to a million? Even by 1,000s? I didn’t think so. All that said, checking out extraordinary records, which these are by definition, is pretty neat.

Also, if you are interested in looking at these records yourself head on over to eBird, click “Explore Data,” then “Explore Region,” choose “World” as your region, and click the “High Count” tab. Beware! You might get addicted to this stuff: I have and it’s not pretty. Let’s take a look at some of what I found so you can make an informed decision as to if this is something you want to get involved in.

The most Green Herons ever reported is 3,000.  The checklist is from 2005 in Nicaragua and the observer who wrote the notes, David Fraser, one of three observers named on the checklist, freely acknowledged that the number is an estimate:

Actual counts difficult to do given the numbers, for the commonest species (Neotropical Cormorant; Great and Snowy Egrets, Little Blue and Green Herons, Laughing Gull, Lesser Yellow-headed Vulture, Northern Jacana) the numbers here are estimates.

Still, even assuming that the number is off by 500 that would still be 2,500 Green Herons, which is a huge number! Of course, the party covered 24 kilometers and took six hours to do it, so it’s not like all the herons were lined up together but still, that is a huge number of herons!

The most Painted Buntings ever reported is 200. The observer, Brush Freeman, covered 71 miles of Texas in six hours in June of 2013 and didn’t even add notes about the world’s largest count of Painted Buntings which, considering the evenness of the number, must be an estimate.

Just one Painted Bunting is enough to make me lose my mind. 200? I would never recover!

The most Gyrfalcons ever reported is 8. Which, to be honest, is kind of disappointing. But I bet Eddie Shea, who reported the eight Gyrfalcons from Alaska in June of 2010, was pretty pleased to see them. Honestly though, I was hoping for a number like one hundred. Now that would be something!

The most of any species ever reported is 76,000,000 Brown-headed Cowbirds. It happened during a Christmas Bird Count in Louisiana in 1984. The same count had 15,000,000 Red-winged Blackbirds and 10,000,000 Common Grackles. The notes on this exceptional number of birds is “counted blackbirds in aggregates of 100,000 and estimated ratios of species every 10 minutes.” That means that the observer counted 1,010 aggregates of 100,000 birds. That is totally nuts. These numbers are clearly very rough estimates and, as was pointed out on the discussion on the Facebook eBird discussion group page, 76 million would be over 60% of the known population of the species of Brown-headed Cowbird. It seems unlikely, but, again, observers are striving to get within an order of magnitude when dealing with counts and if the number was 50 million or 76 million doesn’t matter so much as the fact that there was an insanely large number of cowbirds in Louisiana for that Christmas Bird Count.

Other fun numbers I dug up? The New Yorker in me likes that the world high counts of Black Scoter, Surf Scoter, and White-winged Scoter were all made off Montauk Point in January and February of 2011. Sharon Stiteler, the Birdchick, has the all time high count of Canvasback, in Iowa back in 2010. Some crazy guy reported eight of a mythical woodpecker (and even shared an obviously fabricated video of one of them). The most of any single species of hummingbird ever reported is 906 Anna’s Hummingbirds. The most owls? How about 248 Northern Saw-whet Owls banded in one night?!?!?!

I could go on forever. This stuff is fascinating. If you don’t hear from me within a week or two please send out a search party…or go look for yourself! If you find something cool, please let me know in the comments.

Written by Corey
Corey is a New Yorker who lived most of his life in upstate New York but has lived in Queens since 2008. He's only been birding since 2005 but has garnered a respectable life list by birding whenever he wasn't working as a union representative or spending time with his family. He lives in Forest Hills with Daisy and Desmond Shearwater. His bird photographs have appeared on the Today Show, in Birding, Living Bird Magazine, Bird Watcher's Digest, and many other fine publications. He is also the author of the American Birding Association Field Guide to the Birds of New York.