Why are there so many crows in downtown Portland?

(JANUARY 6, 2019) Crows are migratory birds. Migratory means they move between homes. They live in one place during the winter. Then they live in another place during the summer.

Downtown Portland is one of the places where crows like to live. More and more crows now spend the winter in downtown Portland. There is a website called Portland Crow Roost. It studies the birds in order to learn more about them.

Portland Crow Roost says there are between 5,000 and 13,000 crows in Portland during the months of November, January, and February. The birds migrate in the spring. They move to suburbs or further for the summer breeding season. The summer breeding season is when crows have offspring (babies). From May to July, there are only a few dozen crows downtown. However, other crows return in late August.

People think this might be a new migration pattern. There is little history about the crows in downtown Portland. In fact, news reports say nothing about the large number of crows until 2013. People at that time said they had "never seen anything like it."

Crows usually fly downtown before sunset. They come from many different directions. They gather, fly around, and make a lot of noise. When it is dark, they sleep in the trees. They are quiet until sunrise. When they wake up, they call to each other again. Then they fly out of the city. They travel many miles to look for food. The birds come back again in the evening.

Some businesses and people do not like the crows. They don't want them to be downtown. They think the birds are noisy. They say the birds poop everywhere. It is expensive to clean sidewalks, benches, buildings, and streets. For example, TriMet runs the busses and trains. It spends $1.5 million every year to clean the Portland Transit Mall.

A different organization is trying to solve the problem. The organization is Portland Clean and Safe. It tries to make the crows move. It uses other birds -- falcons and hawks -- to harass the crows.

Some people like the crows. They don't think it is a big problem. They think the crows should be left alone. The birds are a part of nature. Harassing the crows will hurt them, the people say.

It is not clear why the crows migrate to downtown Portland during the winter. There are different ideas. Some people think it is because the weather is warmer downtown. Some people say maybe they like the visibility of streetlights. Others say maybe the tall buildings protect the birds from wind.

Volunteers for the Portland Crow Roost website count the birds. The volunteers study what the birds do and where they go. The volunteers hope the information will help understand the crows better.