Oct 26 2011

Counting Crows

Published by at 7:20 am under Crows, Ravens

The crows are back in town.

Following their pattern of prior years they’ve begun their winter roost in Oakland and will slowly adjust its location until by December they’ll gather west of Polish Hill and roost in the Strip.

Or maybe not.  It remains to be seen.

Right now they fly over Peter Bell’s apartment every night.  On Sunday he shot this video of them flying southwest and pausing on the trees nearby.

Peter wrote on YouTube, “Every fall thousands of crows gather in Pittsburgh. I was lucky enough to be in a spot they all decided to pass over as they decided on a place to roost for the evening.  On this night, it took about 40 minutes from the first few I noticed until most had passed by.  This night they weren’t being too noisy, so most of the recorded audio was buses and other traffic, so I swapped it out.  Music: Schubert’s Serenade (Lied from Schwanengesang D.957) recorded by Anne Gastinel”

Inevitably a flock this large makes us wonder:  How many crows are there?  How do you even estimate their number?  Here’s how.

  1. Note the starting time.  (For example:  5:45pm)
  2. Pick a reference point in the scenery.
  3. Use a timer and count the number of crows passing the reference point for 1 minute or 3 minutes, whichever is most useful.  Make several of these timed counts so you can get a decent average of crows per minute.
  4. Now relax and watch the crows passing by.  If their concentration increases or decreases noticeably, redo the timed counts.
  5. When the crows taper or stop coming, note the ending time.  (For example:  6:30pm)
  6. For how many minutes did the crows pass the reference point?
  7. Use some easy algebra:  minutes * crows/minute = crows.

Ta dah!

You can try this while watching Peter’s video.  Count the number of crows exiting the frame, then multiply by 40 minutes.

How many did you count?

(video by Peter Bell)

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p.s.  Dedicated crow watchers (like me) have been noticing the crows for a couple of weeks.  I predict that everyone else will notice them for the first time on November 7.  Why?  Because we’ll change the clocks (“fall back”) on November 6 and suddenly, on Monday November 7, the crows’ rush hour will coincide with ours.

12 responses so far

12 Responses to “Counting Crows”

  1. Karen Langon 26 Oct 2011 at 8:29 am

    Really cool video Peter. I love when I drive down Polish Hill to the Strip after work, that’s when they start to mass. I have trouble watching the road, because I’m watching the crows. One winter there were so many gathered in the Strip the sky was actually black with crows, people who were out for their evening “smoke” noticed. I got to work early and not only did I see some crows, for some reason they were on Soldiers & Sailors rooftop, I saw both of the Peregrines, who cares if it’s raining :)

  2. sharon leadbitteron 26 Oct 2011 at 10:45 am

    I can’t wait to take more videos and pics this year of the crows. Karen I was in the strip taking video of that phenomena of the crows. I think Kate posted it on her blog. It was so COOL to be a witness to it.

    This year, since I’m not working right now, I’m going to try to get up to the Allegheny Cemetary to take some vids … this seems to be a big meeting point for them.

  3. Mary DeVon 26 Oct 2011 at 5:59 pm

    Very nice! Monday evening when I got home, they were flying over my house. Yes, thousands of them! Coming from the direction of the Parkway & the Mon River, heading north. It was so impressive — several people walking down Ward St. had their eyes on the sky, just watching the endless parade of crows! I didn’t think to count them, or time the procession.

    This morning, I didn’t *see* them, but I certainly heard them — they must have spent the night in the trees by Soldiers & Sailors, and were just waking up and cawing like crazy between 7 & 7:30 AM.

  4. Gintarason 26 Oct 2011 at 6:16 pm

    A Murder of Crows – very good video documentary about crows @ PBS:

    http://video.pbs.org/video/1621910826/

  5. Anne Marieon 26 Oct 2011 at 7:09 pm

    Thanks Peter and Kate! Great video.

    I noticed the crows on Monday night when I worked late. I saw a shadow outside of my window facing Forbes… and when I looked out there were many crows and the sky was growing dark. Yikes! time to leave work! While walking to my car I watched the crows flying and then roosting on Webster Hall and the surrounding area! Cool!

  6. Marianneon 26 Oct 2011 at 9:23 pm

    Cool video! Music is so apropos! Thanks Kate and Peter for sharing!

  7. Kate St. Johnon 27 Oct 2011 at 9:42 am

    Frank Warninsky sent me this link to a New York Times article about Crow Control in Terre Haute, Indiana: http://www.nytimes.com/2011/10/27/us/terre-haute-battles-crow-problem-this-land.html?_r=1&emc=eta1

  8. Mary DeVon 28 Oct 2011 at 4:56 pm

    The past 2 mornings, I’ve noticed them around Soldiers & Sailors — great crowds of crows rising from the trees & rooftops! They are very noisy when they wake up.

  9. Peteron 29 Oct 2011 at 7:49 am

    Well, I got to put this to the test. For sure I need practice (and a vantage point further away would help i think too) but at least 4,000 have just headed in the reverse direction (as shown in the video.)

    And it’s morning so they are noisy and have a lot to say to each other! Not complaining, just saying I’d still be asleep otherwise after staying up celebrating the Cardinals world series win.

    Perhaps that’s what they’re so excited about, a team with a bird mascot winning. That and the weather. I’ve never seen them fly like this in the morning still in such a large group.

    “Cardinals won!”
    “Go Redbirds!”
    “It’s snowing!”
    “Hey look – SNOW!”
    “Wake up, flurries!”

    Yes, everything they’re saying this morning sounds very excited to me. Still flying by now, stretching their wings for the morning. All the stragglers seem to be out there now. The leisurely flyers who prefer to coast and not do any more flapping than they must to keep up.

    One of the fun things I enjoy about our crows is their personalities for lack of better word. As they all fly over you get the guys who are out front beating their wings in the regular relaxed crow motion. You have the coasting guys, I don’t think soar is exactly applicable to them. And then the daredevils who turn around in circles amidst the whole group, or that actually fly counter to the rest. Better yet are the guys that dive through the rest of them as they beeline to a perch high in a tree below. They really can be quite acrobatic!

  10. Susanon 31 Oct 2011 at 6:52 pm

    When I arrive in Oakland early in the morning, I expect to see Alfred Hitchcock. It is straight out of his movie. They are so loud just before sunrise. It’s really remarkable to see and hear. Is there something that attracts the migrating crows to Oakland in particular? A food source? Do the large numbers agitate the falcons at all? Do they ever eat crows, or do they prefer something smaller?

  11. Stephanieon 04 Nov 2011 at 10:22 am

    Kate …. my kids and I have grown increasingly interested in the crows. We’ve lived in Highland Park for 10 years and have grown accustomed to seeing them this time of year but our level of interest has grown. My daughter texted me from the PAT bus on her way to school yesterday to tell me that a bunch of them just flew overhead.
    “Where are they coming from?” “Where are they going?” were the 2 questions we pondered this morning driving towards Oakland, so I told them I’d do some research today.
    I’ve read ‘Outside My Window’ several times over the past few years (mostly about the Cathedral falcons!!) so I decided to see if I could find anything about the crows. Wow! I didn’t expect to spend the last hour reading … and reading. Alot of really great material.
    Now I feel like I can talk with a small bit of intelligence about the crows in Pittsburgh … except … I still can’t determine:
    “Where are they coming from?”
    Are these migratory crows or are they hanging out in the Pittsburgh suburbs and coming to town for the fall/winter roost?
    Thanks!

  12. Kate St. Johnon 04 Nov 2011 at 12:33 pm

    >Are these migratory crows or are they hanging out in the Pittsburgh suburbs and coming to town for the fall/winter roost?
    Probably both. Some are locals who join the winter flock, others are coming from far away.

    The more interesting question to me is, Where do they go every day that we don’t notice 10,000 crows? My guess is that they disperse into the neighborhoods & suburbs and visit the landfills when they have nothing else to do … but I’ve not had time to prove it.

    Check out my Crows & Ravens category for all my musings about them: http://www.wqed.org/birdblog/category/crows/

    And …!… visit Kevin McGowan’s Crow pages: http://www.birds.cornell.edu/crows/
    McGowan is at Cornell & has been studying (and tagging) crows in the Ithaca area since 1988. He knows of tagged offspring that moved away to PA and came back for a couple of days to visit Mom & Dad. Is that cool or what!
    Click on the link to McGowan’s FAQ page for great answers to many of your questions.

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