Counting all crows in Ann Arbor
The American crow (Corvus brachyrhynchos) is plentiful in Ann Arbor in the winter, so plentiful that if you find yourself under the wrong tree at the wrong time you can hear nothing but its cawing and see nothing but black where there used to be a sky.
If this is your first season in Ann Arbor, it's time to think about crows, and to be prepared to not be surprised when you see them. Crows are smart and well adapted to living near humans, and humans are just getting used to dealing with them on their own terms.
How many crows are there?
Every year an annual Christmas Bird Count is done by the local Audubon Society. Volunteers go out and identify and count all of the birds that they can see, and report these numbers in to the national organization. Locally, bird counting has been going on for more than 60 years, so there is some long-term tracking of area bird populations.
Crows are somewhat challenging to count accurately. Because they congregate in large flocks, the ability to accurately measure how many of them there are in an area depends on area birders' knowledge of where they are likely to gather. Dea Armstrong, the City of Ann Arbor ornithologist with the Natural Area Preservation unit, noted that any individual year bird count should not be considered as an exact measure, but rather that population trends should be looked at over a number of years.
The table of data below is from the Audubon Society's Christmas Bird Count database for crows in the Ann Arbor area.
Common American Crow from Audobon's "Birds of America" Volume 4, 1842.
Add this to your list of Top 10 lists for the Ann Arbor area: in a good year, we'll have a nationally outstanding crow population. (Top that, Boulder or Madison.) The Middle River Fork Valley in Illinois is regularly at the top of the crow-counting charts, with bird counts running 10 times what the Ann Arbor area has in peak years.
Why do crows like it here?
Kevin McGowan of Cornell University Ornithology has an excellent Frequently Asked Questions about Crows in which he attempts to answer the broader question of why crows like urban areas. Crow populations near cities all over the country have been growing, so it's not just that crows like Ann Arbor. He notes by way of historical comparison:
A number of possible explanations exist for the relatively recent influx of roosting crows into urban areas. The birds are not making drastic shifts in behavior; crows have been gathering into winter roosts for as long as there have been crows. We know, for example, from work done in the 1930s by John Emlen at Cornell University that approximately 25,000 crows were gathering in a roost near Auburn, N.Y., in the winter of 1932-33, and that a large roost was present in 1911-12 (Emlen, J. T., Jr., 1938, Midwinter distribution of the American Crow in New York State, Ecology 19: 264-275). The big difference is that they were roosting 3 miles south of town then and are roosting smack in downtown Auburn today. Any increase in size of the roost would be imperceptible, compared to the change of locale.
McGowan suggests possible reasons for crows moving to the city instead of the outskirts of town. Cities are warmer than the surrounding countryside, which may be attractive in the winter. There are fewer owls in cities, and the ambient light lets crows see whatever owls there are, helping them avoid their main predator. Urban areas have big trees, protected from logging and preserved in parks, which are suitable for large crow flocks.
Where do they live?
Crows generally feed in the countryside during the day, and come back to town in the afternoon and evening to flock together. Crows gathering in the area in the evening won't have spent their day in western Michigan, notes Armstrong, but they could have been in farm fields throughout the county or in adjacent counties.
The area where crows flock varies from year to year. In the past, black clouds of crows have been seen over the Diag, the Arboretum, Forest Hills Cemetery, the golf courses near Michigan Stadium, and Pioneer Woods. In recent years, a flock has been seen between South State Street and the Ann Arbor Railroad tracks and near the Ann Arbor Airport.
Crows are regular in their habits, and the same crows will show up at the same place time after time.
How do I get rid of them?
Basically, you don't get rid of them. There are so many crows in the area in good years that any effort to scare crows away from one location will simply cause them to move somewhere else nearby.
The Internet Center for Wildlife Damage Management has a guide to crow control, aimed primarily at controlling agricultural damage. It suggests a variety of methods used to scare crows away from your crops, including methods to frighten crows away with loud noises. Some frightening methods used are simply loud explosions, as with propane-powered cannons; others are more subtle and involve playing back recorded crow distress calls.
The University of Michigan has successfully discouraged crows from spending their time on the Diag, much to the relief of students who were tired of the loud noises and the messy crow poop. A 1999 University News Service release describes the use of "what is essentially a flare gun" to disperse crows on campus. "They don't like to be harassed, and, if you do it enough, they'll pack up and go, for a while. Persistence is the key," said University of Michigan pest specialist Dale Hodgson at the time. I attempted to contact Hodgson for this story, but an email was not returned and the phone number listed at the University for him was not a working number.
The amazing intelligence of crows
Crows are remarkably intelligent creatures. This TED talk by Joshua Klein has a wonderful illustration of their inventiveness, culminating in his demonstration of a vending machine operated by crows.
Edward Vielmetti writes about town fauna for AnnArbor.com.
Comments
jcj
Mon, Nov 22, 2010 : 11 a.m.
I used to have a pet crow 50 years ago. It would follow me to the neighbors and if I held out a chunk of burger it would land on my arm to get it. It used to like to follow us into the house. Until one day we did not notice it and the screen door broke its wing. Unfortunately our dog got loose before its wing healed. End of story.
Typha
Fri, Nov 19, 2010 : 8:37 a.m.
I lived in Newberry in 1997, and I used to love watching the crows wheeling and diving as they gathered together. They'd roost up in the tops of the old elms that still stood in front of Angell, and they were the most beautiful sight. You had a choice, be irritated by them, or enjoy them, you can guess what mine was. I doubt they knew that, but they never decorated my coat!
Vivienne Armentrout
Wed, Nov 10, 2010 : 6:50 p.m.
A caution - be careful walking under trees where they are resident. I was hit in the eye and chest by an emission of significant volume and weight. No permanent harm to either the eye or the garment.
Kim Kachadoorian
Mon, Nov 8, 2010 : 5:40 p.m.
I hate the crows and when they try and settle near my house I do a couple of things: 1. bang on a pie tin - that hate that noise so I keep a couple of them around. 2. hit them with a high beam flashlight and whip it around a lot on them - flashing them - they move on If you do either of these go out with an umbrella over your head - when they move away they leave poop and limbs behind. They also leave their dead buddies behind - usually 1-3 of them and then you have to call the county to get them. Once they covered my car in so much crow dung - it took 3 times through the car wash to clean it all off.
applehazar
Mon, Nov 8, 2010 : 7:36 a.m.
What about the thousand or so geese in the field just outside the airport runway on Lohr Rd - Oh I forgot - the airport administration says there are no geese in their FAA report. I must be dreaming. NOT
BHarding
Sun, Nov 7, 2010 : 4:05 p.m.
My stepfather raised a baby crow. It would watch for the news delivery, run out to the curb and grab the paper and plop it onto the workbench, and announce: "newspaper! ". As it got older, it would wander out to visit with other crows, but always come back at night. I remember it speaking about ten or fifteen words regularly, it lived to be about twenty.
Wystan Stevens
Sat, Nov 6, 2010 : 8:40 a.m.
@treetowncartel, this subject brings back memories for me. The first comic book I ever bought in a store (as a kid, in the early 1950s)was an issue of "The Fox and the Crow." I read it and laughed. Eventually I owned dozens of those comics -- but one day, foolishly, I gave them all away to chums in my Burns Park neighborhood. The crow was my favorite character, of course. Here's Wikipedia's take on the subject: http://en.wikipedia.org/wiki/The_Fox_and_the_Crow
treetowncartel
Fri, Nov 5, 2010 : 9:44 p.m.
For those who might have a curiosity, go to you tube and look for fritz the cat and black crow. BTW, the Fabulous Fury Freak Brothers was another great comic from that era.
treetowncartel
Fri, Nov 5, 2010 : 9:06 p.m.
@djm, it was the first adult movie I evedr rented, and to put it in perspective for everybody here is a link that should pass the smell test. http://www.youtube.com/watch?v=VXud20bKJnA&feature=related
Sam
Fri, Nov 5, 2010 : 3:44 p.m.
The October 24 PBS broadcast of Nature, called "A Murder of Crows" demonstrates the amazing intelligence of these birds. Watching them is a pleasure, and putting up with the small inconvenience that they sometimes present is well worth the trouble. The PBS show is viewable online, no charge.
robyn
Fri, Nov 5, 2010 : 3:24 p.m.
I like crows. They're interesting to watch. Way back when I was in elementary school - one of my classmates had a pet crow. His name was Ralph. He used to follow her to school and wait up in a tree or on the rail by the steps for the kids to come out for recess. This was pretty cool until he took a very strong dislike to one of the boys. For no apparent reason - I geuss Ralph just didn't like the way the kid looked. The principal had to make a new rule that Ralph was no allowed to come to school anymore...
rusty shackelford
Fri, Nov 5, 2010 : 3:23 p.m.
I love how they fly in big groups, but so loose and not at all in formation. It's eerie.
Wystan Stevens
Fri, Nov 5, 2010 : 3:13 p.m.
Fifteen years ago, people on my Sunday afternoon tours of Forest Hill Cemetery sometimes were treated to raucous concerts by a cacaphony of crows -- easily 25,000 of them, and quite likely more, high and shrill in the treetops. I understood that the same gang later moved over to State Street, where they chorused all night in the elms in front of Angell Hall. But these days the crows of Forest Hill are down to a relative handful of an evening: decimated, I gathered, by the West Nile Virus. However, I did see a swirling mob of them on Halloween this year; they darkened the sky above State Street as the circled from east to west, Angell Hall to Newberry Hall, and back again. Those who would like to share precious moments with the Forest Hill crows are invited to join me for the last two graveyard tours of this season, on November 7 and November 14, at two p.m. We meet inside the cemetery, where parking is available.
dading dont delete me bro
Fri, Nov 5, 2010 : 2:41 p.m.
http://www.michigan.gov/dnr/0,1607,7-153-10363_10874_11675---,00.html
bugjuice
Fri, Nov 5, 2010 : 2:22 p.m.
They love gathering in the trees in my neighborhood at dusk. I look forward to it every year. It's a sign of the change in seasons.
rusty shackelford
Fri, Nov 5, 2010 : 1:28 p.m.
How far will crows flight out from their home roost in a given day to feed?
Speechless
Fri, Nov 5, 2010 : 1:21 p.m.
Generally I prefer listening to not-yet-counted nighttime crows rather than to the ones Counting on alt rock radio. The collective cacophony emanating from high up among the tree branches can be heard as nature's freeform answer to lively peformances by Edgefest improvisational orchestras. Although perhaps not too practical at this time of year, you can nonetheless legally download these concerts for free by opening the window.
djm12652
Fri, Nov 5, 2010 : 12:50 p.m.
@treetowncartel....oh my...1] you're dating yourself and two, funniest cartoons ever!!!!!
treetowncartel
Fri, Nov 5, 2010 : 12:32 p.m.
Ed, you could have made reference to Fritz the Cat here too.
treetowncartel
Fri, Nov 5, 2010 : 11:58 a.m.
Thanks for the read, very insightful. In recent winters I have seen a flock on Rosedale Street, near the Packard and Platt intersection. In addition to owls, I lived with a cat years ago that attempted to drag one of these things back to the house. I personally adore the Raven more than the Crow.
DennisP
Fri, Nov 5, 2010 : 11:41 a.m.
Just tossing this out to you, Mr. Vielmetti. A brief internet search finds Dale Hodgson as an entomologist with Rose Pest Solutions out of Ohio: http://www.rosepestsolutions.com/why-rose/entomologists Per the biography, he still holds an interest in urban pest populations. The internet can be remarkable can't it?