Crows By The Thousands

Originally posted August 27, 2009

Note: It appears that the crows are not roosting in the usual spot on Nose Hill this year.  If anyone knows of a large night-time crow roost in the city, please leave a comment.

A sure sign that autumn is here is the sight of thousands of American Crows gathering together in huge communal roosts every night.  On August 20/09 at 6:00 pm there were several hundred gathered along the south side of Nose Hill Park west of 14th Street in NW Calgary.  The crows accumulate throughout the evening, arriving from all over the city and from the surrounding countryside, and then move farther into the park to roost in trees overnight.  Yesterday, August 25, I walked into the pre-roost area at 8:45 pm, as it was getting dark. I can only guess at the number of crows gathered there but it surely must have been many thousands.  At 9:00 pm they were still arriving from the south at the rate of about one hundred a minute.

American Crow

This same area was used as a roost last fall.  One observer reported on Albertabird that there were almost 8,000 crows there on August 25, 2008.   The largest night-roost reported, from Oklahoma, had over a million birds!

The reason that crows gather in large roosts like this is for protection from predators, which large numbers in a small area offers.  In the daytime the crows are scattered over hundreds of square miles.  If they were to stay there overnight, they potentially would be prey to the dozens of Great Horned Owls which occupy that large area.  By concentrating in a small area, the crows reduce their losses to a minimum - one or two that might be taken by the owls that occupy this small territory.

Unless you are the kind of person who is freaked out by being surrounded by a huge mob of chattering birds in near-darkness, it is well worthwhile to take a walk to this roost before the crows migrate.  The area is easily accessible.  Park in the lot near Brisebois Drive NW, on the north side of John Laurie Boulevard, about halfway between 14 Street and Shaganappi Trail.  A short walk up the paved path in Many Owls Valley will take you into the midst of the crows.

If you know of another nighttime crow roost in the city, please leave a comment.

Posted by Bob Lefebvre

Previously posted comments:

  • c lannan Says:
    September 22, 2009 at 1:21 am editfor the last two weeks, hundreds (maybe a thousand)crows arrive on the rooftops and fences of Edgebrook Point (which backs on to Shaganappi Trail) across from the NW corner of Nose Hill around 7 p.m and stay for about an hour. Do you have any idea how much longer this will last and if it is likely to reoccur in future years.
    Reply
    • Bob L Says:
      September 24, 2009 at 1:15 am editThe crows will probably depart in mid- to late October. They roosted in the same area last year and sometimes crows will use the same roost for years, so they may be back again next fall. But they do sometimes change roost locations, so maybe not.
      Reply
  • Marlo Says:
    October 2, 2009 at 5:06 pm editLast night (October 1st, 2009) I left my office building about 7:40 pm (around dusk) at 7th Street and 5th Avenue SW. Across the street at MacDougall Centre, there were anywhere from 200-400 crows, maybe more, perched on the building and the park that surrounds it. They were flying back and forth, and you could see massive spots on the sidewalk and street where they collectively relieved themselves. I had never seen any birds on the building as there are gargoyles on the roof to keep the pigeons away, so it came as quite a surprise. My colleage mentioned to me that she’s seen them cluster in that spot around dusk and dawn at this time of year for the last few years now.
    Reply
  • Kevin Says:
    October 5, 2009 at 1:31 am editI have been working the graveyard shift @ my work downtown on 3rd Ave and 6th for the past week. I have noticed that every evening hundreds of these crows fly in from the north between 7:00pm – 7:15pm, and perch themselves on the nearby apartment buildings. It’s almost eerie to watch, with their precise timing and all, and if you’re ever up to see, they all flee back to where they came around sunrise. A word of warning though, make sure you carry an umbrella if you’re in the area then.
    Reply
  • Darlene Says:
    October 12, 2009 at 11:59 pm editThank you to all who took the time to put these comments in. I just watched a program about crows, and they are quite smart. I used to feed them in my backyard and am fascinated with them. I will for sure be out with umbrella to watch them next year at McDougal and Nose hill.
    Reply
  • Sara Says:
    October 29, 2009 at 5:17 am editwe just got freaked out but the hundred or so crows roosting in the trees surrounding our house tonight. about a mile from the park but still in a populated residential area. i was worried it was some sort of bad omen.
    Reply
  • Rob Jobst Says:
    February 25, 2010 at 8:54 am editThe Mount Royal Escarpment, which separates eastern Mount Royal from the community of Cliff Bungalow, sees hundreds of crows gathering every evening from mid- to late-summer through some point in the fall. If you want to take in a good show, go to the little park at 5th Street and 24th Avenue SW and watched the “squadrons” of crows fly in from the east and settle on the wooded hilllside. Every once in a while they will get spooked and all explode into the sky at once and the sky almost goes black with the hundreds of swirling crows. I very much enjoy the spectacle from my apartment a block away, but I wouldn’t want to be those people that live in the condos right across the street from the roost… 800 crows make a lot of noise!
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