I heard this story many times in my childhood but never as well told as it is in Wild Birdwatchers I Have Known by Gerry Bennett. Here is his account.
Several winters ago a barred owl showed up in the downtown district of Toronto. There was a tree at the back of the Y.M.C.A. building where it frequently spent the day. Birders enjoyed walking down an alleyway behind the “Y” and, with no more effort than looking up, adding it to their winter list.
The owl spent a most pleasant winter. For lunch it had only to knock a pigeon off the eave of a nearby building. Following this, a comfortable nap in the one and only tree in the neighbourhood got the day in rather nicely.
One of the employees at the “Y” developed quite an affection for the bird and started leaving the window of a vacant third-story room open in case the owl might like a warmer place to spend the night. Sure enough, the owl moved right in and would often roost on the foot of an old iron bedstead.
Birders didn’t like this at all at first because the bird was no longer easy to find from the street. However, word soon got around that if you wanted to see the owl you should ask for the caretaker. If the owl was in, he would say, “Yes, she’s up in her room.” He would then escort you to the door and there would be the owl looking at you whammy-eyed.

Gerry Bennett