Crow roosts can range from small scattered roosts of under one hundred individuals to the spectacularly large roosts of hundreds of thousands, or even more than a million crows! These large, black birds can be difficult to tell apart from one another, especially at a distance. It's not just your imagination: Why a murder of 10,000 crows takes over Ottawa in the winter Crows have marked an area of Ottawa as a roost area. Where crows go in the winter — and other stories about migration We see them ever so often, but there's so much still shrouded in mystery. They often warn their flock if there is danger ahead. There are about 13,000 crows roosting together, according to an estimate by Kevin McGowan, an ornithologist in the Cornell Lab of Ornithology. Large flocks of crows — poetically called "murders" — are not unusual in the winter, but this year's flock is larger than normal in Ithaca. Build or buy crow birdhouses and roost boxes. One possible reason is that a flock provides better protection from predators. “If you live in a place, usually a city, with a huge winter flock of crows, you are seeing migratory birds that came south for the winter as well as your local, year-round crows,” says Townsend. Moreover, they can also find new friends and mates if they get the chance to belong on different flocks. There are some big advantages to flocking. Like many other species of birds, crows and ravens engage in what’s called communal roosting. Each morning the flock splits up and disperses in search of food, including such things as corn stubble or seedy grass. Birds of a Feather — Why Crows Congregate in Winter This time of year, there's an evening spectacle taking place in treetops in cities, towns and around the countryside. Want to help keep crows warm in the winter? Keep your feeders full, check daily. It is a common thought that there is increased survival if they are together. They can be alarmed easily if there are predators or people near to them. Crows have been congregating in large roosts in the fall and winter for as long as there have been crows. Each bird in a massive-size flock doesn’t have to be quite as vigilant as it would be if it was flying solo. 1)Why do I see large groups of crows flying over my house every evening? Safety is their main agenda. This is where groups of both kin and unrelated individuals flock to a particular location for, in part, the security of safety in numbers while they sleep. Put out winter bird foods such as suet, the bird peanut butter, seeds and other bird foods high in fat. Some Birds Use Their Brains to Survive Winter Explore the winter world of smart birds who store food and share secrets. They also lead one another to a source of food if there’s any. Or, why flock only in winter? This will save them the energy of trying to find water. Each winter a murder of thousands of crows would gather in the local Walmart parking lot and create a ruckus filled with cawing and pooping. While a few people I know enjoyed watching the crows, they created an unfavorable reaction among locals. There are several reasons why members of the corvid family, which includes several species of both crows and ravens, might make circles in the air. "If you live in a place, usually a city, with a huge winter flock of crows, you are seeing migratory birds that came south for the winter as well as your local, year-round crows," says Townsend. While crows tend to be mostly solitary, territorial birds in the summer, winter will find them congregating in "roosts" of a few hundred to a thousand or more birds at night. The Churchmans flock is one of about a dozen winter flocks in Delaware, according to Williams. As to why a bird would decide to hang out with millions of other birds each winter, scientists have several theories, says Williams. Posted Jan 31, 2013 They efficiently pass information by means of gathering into a particular place.