Is it normal for crows to stay in large flocks of around 200 birds all summer long starting in the spring?

Question

Where I live in Northern Ontario, Canada there is a huge flock of crows that nest in a big colony starting in the spring and lasting all summer long, then they break up in winter. I have looked up information but there is no mention of this behaviour, and no they are not rooks they are Common Crows and they all nest in one spot near where I live and they fly out in the morning and back at night. I am just wondering if anyone has seen this before and if you can direct me to more information about this behaviour..

Mr C crows do not destroy trees...WTF! are you on crack?? A whole freakin colony of them doesnt even destroy trees....

jiggyscrewy I have read about winter roosting habits but this is in the spring and summer in nesting time...

All of these links describe WINTER and FALL flock behaviour, these crows do it every spring every year and it is the first sign of spring to me because they start thier huge flock when it starts to get warm and break up in the winter...every thing I read posted here says the exact opposite!! It says the gather only in winter.

Answer 1

Crows form large family groups, there are territory holders and what are known as floaters. The territory holders are usually related even if the generations are far apart. The floaters are unpaired males and females that fly around the territory waiting for the opportunity to steal a mating or to userp a nest site.

I have never heard of 200 hundred individuals, but I have seen about 2 dozen before. I am also from Montreal, so the chances of finding optimal habitat like in Northern Ontario is quite rare. So I guess under optimal conditions, these groups could potentially reach large numbers.

I hope this answers your question. I have read several ethology books in my day and read things about grouping behaviour of crows, maybe try something like that for a little more information!

Answer 2

Crows tend to follow food. If you are in N.Ontario, they will probably be gone in a few weeks. Some people (scientists included) have begun to track these "flocks" Or "murders" (it is called a murder of crows-seriously) to see if there is a tendency of them being able to predict weather patterns, not just by looking for food, but also barometric pressures, temps and even ionic activity in the upper atmosphere. If you are near a library, a lot of good papers have been published about murders of crows in the journal "Nature".

Answer 3

I have seen them too. Some cities here up upstate NY (USA) are just plagued by them...huge flocks of them. They try to get rid of them but having difficulty.

http://www.audubon.org/bird/BoA/F18_G1b.html
http://www.birds.cornell.edu/crows/planta.htm
http://www.birds.cornell.edu/crows/crowfaq.htm
lots of interesting facts about crows, and lots of info about roosting spots in the fall and winter (up to million crows can congregate in roosting spots), but can't find any info on spring/summer roosting behavior ..maybe because you are so far north they act differently?

Answer 4

If they're right outside your window it sounds like 200 birds. Damn crows. I hate em. After they get done destroying the tree, they'll move on to another one... hopefully not near you!

Answer 5

That is odd....your right, it is usually the opposite, they should be pairing up in the spring, and then when breeding season is over getting back into their flocks to disperse.

Answer 6

Have you seen the movie the Bird's by Alford Hitchcock

Answer 7

yes in Auburn NY
http://www.cnylinks.com/crows/
there are many websites about the crows in Auburn because they are killed to lower their numbers because of the fear of west-nile virus

Answer 8

sounds ok to me...