How Many Blue Jays?

Great Backyard Bird Count 2019

In the winter of 2012 Pittsburghers noticed we had very few blue jays in our area. It was such a mystery that I posted an article in February asking folks to tell me if they’d seen any blue jays lately. Seven years later the responses are still coming in.

Most people respond when they don’t see any blue jays because they miss them. It turns out that blue jay frequency varies throughout the year and can drop locally when the habitat changes, especially if oaks are cut down. (Blue jays rely on acorns.)

Our blue jay count surges during spring and fall migration because a lot of them breed north of us. In Allegheny County (Pittsburgh) there’s also a mysterious mini-surge every year in mid February. What’s that about?

eBird frequency of blue jays in Allegheny County, PA, 2014-2019

See seven years of blue jay reports and musings at Have You Seen Any Blue Jays Lately?

Count your own blue jays during the Great Backyard Bird Count this weekend. How many birds will you find?

(image credits: Great Backyard Bird Count poster, eBird report on frequency of blue jay sightings in Allegheny County, PA, 2014-2019; click on the captions to see the originals)

5 thoughts on “How Many Blue Jays?

  1. I may not see any blue jays for a while, but within a minute of putting out peanuts, especially in the shell, I’ll have a dozen. (Albany, NY, area.)

    I think you posted something a while ago that showed that they weigh the peanuts before choosing the heaviest one. I see them do that, too, but I didn’t realize why until reading your post. 🙂

  2. Can we assume that fewer bluejays in Pittsburgh has something to do with the Oak Wilt — lots of trees being cut down?

  3. Lots of blue jays (and oaks!) in Allegheny Cemetery, but I didn’t start seeing many around my house until December. I hear one outside right now!

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