Pittsburgh bird spotlight: the American crow

As I was at the bus stop waiting for a 61D in Squirrel Hill to come to campus on Saturday evening, I witnessed a very interesting event: over a thousand crows flying over my head over the span of five minutes. To me, I think the most interesting part was that no one else was paying attention to what was happening above them. Out of the 20-something people that walked by me on the street, I only saw one person look up at them. So why were there so many crows flying above Squirrel Hill?

The answer is that crows will stay in southern Pennsylvania for the winter in flocks of thousands. The region has mild winters and an abundance of food over the cold months. Crows go out during the day to search for food and return at night to their roosts — places where flocks of crows have sometimes been seen gathering for decades. Many of these birds follow the same flight path every day they go out for food.

I had witnessed a flock of crows returning to their roost for the night. It was entertaining watching as they flew overhead; they came in short bursts, so I kept expecting the last crow, but they kept coming. Occasionally, one crow would run into another and they would have a little fight.

While crows are found in Pennsylvania year-round, some migrate south for the winter while others stay local and forage. This makes them partial migrants. Younger crows are more likely to migrate while older crows are more likely to stay around their nest year-round.

These birds usually fly somewhere between 25 and 30 miles per hour. However, if a strong tailwind is blowing, crows can reach up to 60 miles per hour. Crows have good maneuverability when in flight, meaning they can throw off airborne predators.

During winter, crows have been observed to fly up to 30 miles in a single day in search of food. Their diet consists of grasshoppers, caterpillars, grubs, worms, most insects, grain, fruit, the eggs and young of other birds, and organic garbage. As a general rule of thumb, they will eat anything they are bigger than and can also overpower. They have also been observed eating the carcasses of roadkill.

While crows are predators of songbirds and waterfowl, they are also prey for some larger birds. Young crows and eggs fall victim to raccoons, opossums, and tree-climbing snakes if left unprotected. Hawks and owls will also attack crows in all life stages; they are especially vulnerable to night attacks from great horned owls. As a result, when crows spot owls and hawks during the day time, they will mob it. Mobbing involves crows swooping, calling out to other crows, and harassing the predator. However, crows will also be mobbed by smaller birds like kingbirds and red-winged blackbirds.

The next time you’re out and you hear a bird cry, look up. There’s a chance there’s hundreds of birds right above your head.