We had our first proper snow yesterday and the flock of crows was visiting the berm area. In recent years every fall and winter a flock of crows forms in Ottawa. Each evening they pass Manordale in a long steady stream heading back to their roost on the Rideau river. They don't clump together and often you only see a few flying by at a time but it is a steady stream that mounts to hundreds passing over head in just a few minutes. Yesterday a part of the flock settled in the trees along the berm. Their tracks were all over the place in the fresh snow. They seem to be very mindful of what the passing human is doing; as soon as I stopped to take out my camera, a large portion of the flock flew off.