If you walk out of the main doors of the Hilton in Portland at night, you will find strange and dark things in the trees that line the section of 6th Avenue between Salmon Street and Taylor Street. At first, you will think it's just some lame public art work that city promoters hope will capture the weird spirit of the town. But a little movement in the dark branches will make you think twice. You will readjust your eyes and realize the things in the trees are crows. Hundreds of them. Just sitting up there. Almost as still as a work of art.

After a moment, your attention leaves your eyes and settles in your ears, which have detected the patter of something that's clearly much heavier than rain. It is crow shit. It's falling all of the time. You look on the ground: shit everywhere. It then quickly enters your awareness that if you do not move to a spot clear of the trees, you will be hit by what remains of all the garbage and roadkill those omnivorous birds ate during the day.

"They come every night," a handsome and young concierge will tell you. "They like it here because the buildings block the wind. It's nice and peaceful. The people who clean the streets have to shake the trees to get rid of them, but they always come back here."

According to a piece in October in the Oregonian, the crows of Portland roost together in the city in the cold and dark seasons. When night falls on the city, they fill the sky with their flights to parks and streets sheltered by buildings. The city is where these birds want to be. This is how they "remind humans that [the] city does not entirely belong to them." These animals are with us. We have become a dependable niche for their wild lives.