What happens in the night

Posted September 16th, 2011 by kcorliss. Comments (2).

In the big scheme of things this technology is fairly new–Doppler radar–particularly as it pertains to bird migration. I don’t have the time to dig into the research but it was someone from the Southeast who came upon this tool as a way to track migrating birds. Some of the radar images from the Gulf Coast are truly astounding as it pertains to birds migrating across the water.

I have previously confessed to a lack of understanding as to the manipulation of Doppler for birds (as an aviator I get the weather side of it). Others in the business, however, have a keener sense, especially the weather dudes.

It came into my inbox just the other day. Turns out it was Tuesday morning of this week. A time lapse video from that night that just happened to capture the intensity of bird migration, was recorded by a guy from Grand Forks. I offer up a still from said video with a confession that I can’t figure out how to post the entire video. Still, you get the idea. Lots and lots of migratory species heading out of territory for the season only to be seen again next spring. Here’s one of the screen captures:

It’s not as if the birds themselves are flying in a donut-shaped pattern. No. It’s merely the section of the sky the radar happens to be sampling at the time the shot was captured. As you can see, for reasons only the birds know for certain, this was a night for massive movement. Pretty cool.

Thanks goes out to Daryl Ritchison for keeping me in the loop and to Mark Ewens, who captured the video in question. Pretty impressive for North Dakota (and western Minnesota).

2 Responses to “What happens in the night”

  1. Andrea

    Here’s an easy way for your readers to see an animated loop of the radar for Tuesday:

    (1) Go to .
    (2) Enter “Grand Forks, ND” in the search bar.
    (3) Scroll down to the first radar map (just below “weather at a glance), and put your cursor over it. You should be able to select NEXRAD.
    (4) Scroll down. Just below the map and to the right, you can pick a date on the Radar Archive. Enter September 13, 2011, and hit “View Archived Image.”

    The big green and grey donuts at the start of the image are birds, bats and insects in the air. As sunrise approaches, they land. Throughout the day you can see various small precipitation events move through. Then, at about 9:00 or 10:00 PM, the donuts reappear as the birds again take flight.

    If you compare that loop to the one for September 15, they are totally different – no bird migration that day! And, this makes perfect sense because it looks like the winds on the 13th were northerly, and on the 15th they were southerly.

    One other really cool place to look for birds on radar is at . Click on the tab marked “Radar,” and then click on “Loop of this image.” If you do this in the evening, you see a progression of donuts from right to left across the country.

    The best site I know for learning about NEXRAD and birds is at . They have easy-to-understand explanations of how NEXRAD works and why it’s a useful tool for bird migration.

  2. kcorliss

    For whatever reason (filters?) Andrea’s links to websites were not included in her comment. Here are her three references in order of appearance: wunderground.com, nws.noaa.gov, and virtual.clemson.edu/groups/birdrad/

    Hope this helps and thanks for the info Andrea. Clemson’s site was the one I had referenced in the past on this blog and have found it very instructive.